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MOSBY’S COMPREHENSIVE REVIEW FOR VETERINARY
TECHNICIANS, FOURTH EDITION ISBN: 978-0-323-17138-0
Copyright © 2015 by Mosby, an imprint of Elsevier Inc.
Copyright © 2008, 2003, 1998 by Mosby, Inc., an affiliate of Elsevier Inc.
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any
means, electronic or mechanical, including photocopying, recording, or any
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This book and the individual contributions contained in it are protected under copyright by the
Publisher (other than as may be noted herein).
Library of Congress Cataloging-in-Publication Data
Mosby’s comprehensive review for veterinary technicians / Monica M. Tighe, Marg Brown. – Fourth
edition.
p. ; cm.
Comprehensive review for veterinary technicians
Includes bibliographical references and index.
ISBN 978-0-323-17138-0 (pbk. : alk. paper) 1. Animal health technology. I. Tighe, Monica M., editor.
II. Brown, Marg, editor. III. Title: Comprehensive review for veterinary technicians.
[DNLM: 1. Veterinary Medicine–methods–Examination Questions. 2. Veterinary Medicine–methods–
Outlines. 3. Animal Technicians–Examination Questions. 4. Animal Technicians–Outlines. SF 774.4]
SF774.4.M67 2015
636.089073'7069--dc23
2014016500
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Content Manager: Shelly Stringer
Publishing Services Manager: Jeff Patterson
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Printed in China
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NOTICES
Knowledge and best practice in this field are constantly changing. As new research and experience
broaden our understanding, changes in research methods, professional practices, or medical treat-
ment may become necessary.
Practitioners and researchers must always rely on their own experience and knowledge in evaluating
and using any information, methods, compounds, or experiments described herein. In using such
information or methods they should be mindful of their own safety and the safety of others, including
parties for whom they have a professional responsibility.
With respect to any drug or pharmaceutical products identified, readers are advised to check the
most current information provided (i) on procedures featured or (ii) by the manufacturer of each
product to be administered, to verify the recommended dose or formula, the method and duration
of administration, and contraindications. It is the responsibility of the practitioners, relying on their
own experience and knowledge of the patient, to make diagnoses, to determine dosages and the best
treatment for each individual patient, and to take all appropriate safety precautions.
To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors assume
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![Chapter 1 Animal Anatomy and Physiology 13
C. Atrial systole: atria are contracting
1. Sinoatrial (SA) node fires, causing contraction of
the atria; blood is pushed through the tricuspid
andbicuspidvalvesintotherightandleftventricles
D. Ventricular diastole
1. Ventricles receive blood from the atria
E. Ventricular systole
1. Impulse from the SA node has been conducted
to the atrioventricular (AV) node, which con-
ducts the impulse down the bundle of His (AV
bundle) to the Purkinje fibers
2. Ventricles are now stimulated to contract;
blood is forced through the semilunar valves
into the pulmonary artery to the lungs, and out
of the aorta to all parts of the body
VIII. Heart sounds
A. Auscultation (listening to heart sounds)
1. Lubb, dupp, pause
a. Lubb is the first sound; it is a long sound
made when the AV valves close
b. Dupp is the second sound; it is a short, sharp
sound made when the semilunar valves close
IX. Heart rate
A. Animal heart rates vary with age, size, breed, health,
and fitness; heart rate is also affected by chemicals,
hormones,temperature,behavior,andrespiratoryrate
B. Dog: 70 to 160 beats per minute
C. Cat: 150 to 210 beats per minute
D. Horse: 28 to 50 beats per minute
E. Cattle: 40 to 80 beats per minute
X. Electrocardiography (ECG [or EKG])
A. Electrocardiogram records the electrical activity
of the heart
B. First wave is the P wave, which represents the elec-
trical events during atrial systole (depolarization)
C. Large QRS complex represents the electrical events
of ventricular systole (depolarization)
D. T wave represents the electrical events during ven-
tricular diastole (repolarization)
E. Atrial diastole occurs during ventricular systole;
therefore it is masked by the QRS complex
Central Vascular System
I. Blood vessels
A. Arteries
1. Carry blood away from the heart
2. Carry oxygenated blood (except for pulmonary
artery)
3. Are thicker and stronger than veins
4. Pressure within is greater than in veins
B. Arterioles
1. Small arteries
2. Lead to capillaries and regulate the blood flow
into them
C. Capillaries
1. Consist of one layer of endothelium
2. Microscopic diameter
3. Exchange of oxygen and carbon dioxide takes
place here
D. Venules
1. Emerge from capillaries and enlarge into veins
E. Veins
1. Are larger than arteries and have thinner walls
2. Venous blood pressure is low; therefore they
have valves to prevent the backflow of blood
3. Carry blood back to the heart
II. Blood pressure
A. The force exerted by the circulating blood on the
vessel walls
B. Systolic: Force exerted during contraction of the
ventricles (maximum)
C. Diastolic: Force exerted while the ventricles are re-
laxed (minimum)
III. Fetal circulation
A. Lungs, kidneys, and digestive tract are nonfunc-
tional in fetus but must be nourished with oxygen
B. Exchange of nutrients and waste takes place within
the placenta
C. Oxygenated blood enters the fetus via one umbilical
vein
D. Vein ascends toward the fetal liver and divides into
two; one branch joins the hepatic portal vein and
enters the liver, and the majority of blood flows into
the ductus venosus, which connects to the postcava
E. Postcava enters the right atrium; precava from the
head also enters the right atrium
F. Most of the blood goes directly through the fora-
men ovale to the left atrium, into the left ventricle,
and out of the aorta to all parts of the fetus
G. Blood that goes into the right ventricle passes
into the pulmonary artery; most blood is diverted
through the ductus arteriosus into the aorta (a small
amount goes to the lungs)
H. Blood in the descending aorta branches into the
iliac arteries; the two umbilical arteries branch off
and return deoxygenated blood to the placenta
I. Both the foramen ovale and ductus arteriosus close
shortly before birth
Digestive System
The digestive system breaks down foodstuff into absorb-
able nutrients to fuel the body. There are anatomical varia-
tions among different species depending on their diet.
I. Process
A. Digestive system uses five basic processes to prepare
the food for utilization by the body
1. Ingestion of food
2. Mechanical and chemical digestion
3. Peristalsis: moving food through the digestive
tract via smooth muscle contractions
4. Absorption
5. Defecation
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![Chapter 1 Animal Anatomy and Physiology 17
D. Urethra
1. Tube of smooth muscle to transport urine from
the urinary bladder to the exterior
II. Physiology: three phases to urine production
A. Filtration
1. Blood enters glomerulus by the afferent arteriole
2. Various pressures cause water, salt, and small
molecules to move out of the glomerulus into
Bowman’s capsule
a. The filtrate is now called the glomerular fil-
trate; rate at which it is formed is called the
glomerular filtration rate (GFR)
B. Reabsorption
1. Occurs in the PCTs and loop of Henle;substances
needed by the body are reabsorbed from the glo-
merular filtrate into the peritubular capillaries
C. Secretion
1. Substances are selectively secreted from the peri-
tubular capillaries into the DCT
III. Urination (micturition)
A. The voiding of urine
B. Filtrate flows into collecting ducts,renal pelvis,ureter,
urinary bladder, and urethra and is voided as urine
C. Urine is water plus waste products (e.g., urea, excess
ions)
IV. Hormonal influence
A. Antidiuretic hormone (ADH [vasopressin])
1. Increase in ADH release increases the reabsorp-
tion of water within the kidney
B. Aldosterone
1. Stimulates sodium reabsorption in the kidney
Reproductive System: Male
I. Male anatomy
A. Testicles
1. Two oval glands in a skin-covered scrotum
2. Seminiferous tubules produce sperm
3. Interstitial cells of Leydig produce testosterone
4. Epididymis adheres to the side of the testicle; it
connects the seminiferous tubules to the vas def-
erens and provides storage for sperm and a place
for maturation
5. Testicles develop inside the abdomen but de-
scend into the scrotum (after birth in dogs and
cats), where the body temperature is more favor-
able for sperm development
B. Vas deferens (ductus deferens)
1. Connects the epididymis to the urethra
2. Is a part of the spermatic cord, along with blood
vessels and nerves
3. Spermatic cord passes through the inguinal ring;
at this point, the vas deferens separates and joins
the urethra
C. Accessory sex glands
1. These glands produce semen
2. Semen provides a transport medium for sperm,
protectsthespermagainsttheacidityinthefemale
genital tract, and provides a source of nutrition
3. Glands vary with the species
4. Dogs have a prostate only
5. Cats have a prostate and bulbourethral (or
Cowper’s) glands
6. Stallions have seminal vesicles (vesicular glands),
prostate, bulbourethral glands, and ampulla
D. Penis
1. Houses the urethra, which transports sperm into
the female genital tract
2. Consists of a shaft and the tip, known as the
glans penis
3. Erectile tissue surrounds the urethra; with sexual
excitement the tissue becomes engorged with
blood, leading to an erection, followed by the re-
lease of sperm during ejaculation
a. Penis of the cat, dog, and stallion is composed
of mostly erectile tissue and a small amount
of connective tissue
b. Penis of the bull, ram, and boar is composed
of mostly connective tissue and very little
erectile tissue
(1) These animals achieve erection by the
straightening of the sigmoid flexure of
the penis
4. Dog penis is unique in that it has a very long
glans penis
5. Cat penis is retracted and covered with spiny epi-
thelial projections
Renal
corpuscle
Bowman's
capsule
Capsular
space
Glomerulus
Efferent
arteriole
Afferent
arteriole
Distal
convoluted
tubule
Branch of the
renal artery
Ascending
loop of Henle
Descending
loop of
Henle
Peritubular
capillaries
Peritubular
capillaries
Proximal
convoluted
tubule
Collecting
duct
Renal
cortex
Renal
medulla
Branch of the
renal vein
FIGURE 1-5 Microscopic anatomy of nephron. (From Colville T,
Bassert JM: Clinical anatomy and physiology for veterinary
technicians, ed 2, St Louis, Mosby, 2008.)
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![20 PART l Anatomy and Veterinary Diagnostics
2. Change the permeability of an organelle
3. Activate or inactivate an enzyme system
4. Change the rate of enzyme production
II. Control
A. Hormone secretion is most commonly regulated
through a negative feedback system; as the hor-
mone levels rise, their secretion is inhibited
B. Only the adrenal medulla is under neural control
Integumentary System
Anatomy
I. Skin consists of two layers of skin and one underlying
layer of subcutaneous tissue (Figure 1-6)
A. Epidermis
1. Superficial layer is the stratum corneum; this is
a nonvascular, cornified layer, 20 to 30 rows of
keratocyte “remnants,” constantly being shed
and replaced
2. The next layer is the stratum lucidum. Found
only in thick skin, this layer is composed of a few
rows of flattened dead cells
3. The granular middle layer or stratum granulo-
sum consists of two to four layers of flattened
keratocytes that help waterproof the skin
4. The stratum spinosum contains several layers of
cells held together by desmosomes, Langerhans’
cells found in this layer
5. The deepest layer is the actively growing stratum
germinativum or stratum basale; contains mela-
nocytes (pigment cells)
B. Dermis (corium)
1. Deep to the epidermis
2. Contains arteries, veins, capillaries, lymphatics,
and nerve fibers
C. Hypodermis
1. Deep to the dermis is the subcutaneous layer
consisting of connective and adipose tissue
Function
I. Protective barrier, sense organ, and site for vitamin D
synthesis
II. Contains many glands and nerve receptors (e.g.,
Meissner’s corpuscle [touch receptor], sweat glands,
Ruffini’s endings [heat receptor], Pacini’s corpuscles
[pressure receptor], sebaceous glands), melanocytes
(pigment cells [produce melanin, giving skin its
color])
Hair
I. Hair contains an inner medulla covered by the thicker
cortex, which in turn is covered by a keratinized layer
called the cuticle
II. Hair is produced within a follicle, with growth origi-
nating in the bulb region
FIGURE 1-6 Canine skin. (From Colville T, Bassert JM: Clinical anatomy and physiology for veterinary technicians, ed 2, St Louis,
Mosby, 2008.)
Compound
follicle
Scalelike
folds
Hair shafts
Free nerve
ending
Sebaceous
(oil) gland
Sebaceous
(oil) gland
Arrector
pili muscle
Hair root
Nerve
Artery
Vein
Pacinian corpuscle
Adipose (fat) tissue
Meissner's
corpuscle
Epidermis
Dermis
Hypodermis
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![26 PART l Anatomy and Veterinary Diagnostics
a. Simple, noninvasive procedure but unsatis-
factory for bacterial culture
b. Preferably, a midstream sample is collected,
avoiding initial or end portion of the voided
urine
c. Vulva or prepuce should be cleansed before
collection
d. Variations
(1) Commercially available absorbable
urine sponges
(a) For chemistry and physical evalua-
tion only
(b) Not for microscopic urinalysis
(2) Litter pan
(a) Replace regular absorbable litter
with inert non-absorbable litter
(3) Manual expression
(a) Must be performed with care and
patience; avoid excessive pressure
to the bladder
(b) Should never be attempted on an
animal with a suspected urethral
obstruction
(4) Metabolism cage
(a) Usually of value to determine urine
volume only
(b) Extended time between collection
and testing may increase the possi-
bility of contamination and sample
degradation
(c) To assist in maintaining sample qual-
ity, cold pack collection reservoirs
are available, as are alarm-sensitive
cages, which alert personnel to the
presence of a sample
(5) Tabletop, cage, floor
(a) May be adequate for screening if the
surface iscleanandfree of disinfectant
residues,and the sample is analyzed in
an expedient manner such as POCT
(b) These samples are usually contami-
nated, not suitable for bacterial cul-
ture, and offer limited diagnostic
information
(6) Client-collected samples
(a) Usually, client-collected samples
are not satisfactory because of im-
proper collection procedures, the
extended time between collection
and testing, and the use of im-
proper containers and storage
(b) Although not always practical, it is
best to have the client bring the pa-
tient to the clinic
(c) Under these circumstances, the cli-
ent should be asked to discourage
the pet from voiding urine for 2 to
3 hours before the appointment to
facilitate collection at the clinic
2. Cystocentesis
a. Perform by inserting a needle through the
ventral abdominal wall and into the urinary
bladder
b. Perform the procedure using aseptic tech-
nique on a patient with a full bladder, thus
providing a better anatomical reference and
minimizing possible damage to other ab-
dominal organs
c. Collection through cystocentesis avoids
contaminants from the lower portions of the
urinary tract, making the sample suitable for
bacterial culture
3. Transurethral catheterization
a. Performed by passing a rubber, plastic, or
metal catheter through the urethra and into
the urinary bladder
b. Type and size of catheter depends on size,
gender, and species of animal
c. Catheterize as aseptically and atraumatically
as possible to avoid complications for the
patient and catheter-induced cellular and
bacterial contamination of the sample
d. Sample is aspirated into a syringe attached
to the exposed end of the catheter
D. Preservation
1. For microscopic evaluation, centrifuge imme-
diately
2. Refrigerate (~35° to 46° F [~2° to 8° C]) for
an additional 2 to 12 hours if necessary, but
bring sample to room temperature (~68° to
77° F [~20° to 25° C]) before evaluation, es-
pecially if evaluating specific gravity (SG) and
crystals
a. Cold urine may also interfere with enzymatic
reactions on the urine chemistry dipsticks
3. Freezing (≤32° F [≤ 0° C]) is satisfactory for
common urine chemical analytes, but will most
likely destroy the cellular elements
4. Chemicals
a. The sample can be preserved by the addition
of acidifiers (e.g., boric acid or hydrochloric
acid), formaldehyde, toluene, thymol, phe-
nol, chloroform, sodium fluoride, and com-
mercial chemical urinary preservatives
b. Although one or more urine elements may
be preserved by the chemical, it may be at
the expense of other elements in the urine
E. Sample variables
1. Samples should be analyzed within 20 to 30
minutes of collection to maximize validity of
information and minimize post collection ana-
lytical variables
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![Chapter 2 Urinalysis and Hematology 27
2. One, more, or all results may be directly or in-
directly influenced by non-pathological inter-
nal and external influences (e.g., exercise, water
intake, diet, medication, collection method,
degree of restraint, environmental factors [e.g.,
temperature, humidity])
a. The veterinarian interprets individual test
results in light of these variables, with the
results of other urine and clinical evaluation
procedures, and in concert with the physical
examination and history
3. Pre-collection and post-collection (pre-analyt-
ical), “artifactual” or iatrogenic variables may
increase or decrease values, resulting in false-
positive or false-negative results.
4. See Table 2-1 for variations that affect test results
II. Physical evaluation
A. Terms related to urine volume and output
1. Anuria: complete absence of urine formation
or elimination
a. Can occur from renal shutdown; usually as-
sociated with obstruction
2. Continence: storage of urine in the bladder as it
fills
3. Dysuria: difficulty or pain on urination
4. Incontinence: dribbling of urine at frequent
intervals
a. Commonly occurs in dogs because of con-
genital abnormality of the ureters or urethra
5. Micturition: physiological term for emptying
the bladder
a. Commonly referred to as urination
TABLE 2-1 Variation to Deterioration of Sample and Influences on Test Methods
Component Variation
Ammonia Increase from proliferation of urease-producing bacteria
Bacteria Increase from the in vitro proliferation of bacteria that normally inhabit the vagina, labia, urethra, or
prepuce or arise from urinary tract infections or contamination from external sources
Bacterial concentration approximately doubles every hour at room temperature (~68°-77° F [~20°-25° C])
Bilirubin Decrease from exposure to light and oxidation at room temperature
Casts Decrease due to alkalization (pH 7.0) or dilution of urine (SG~1.008-1.010)
Color Darkens with exposure to light and urochrome degradation
Brown-black discoloration with blood substitutes
Crystals Types and numbers increase or decrease with pH and temperature changes (colder temperature causes
increase)
Erythrocytes Hemolysis caused by dilute and/or alkaline urine, or freezing
Glucose Decrease from metabolism by cells or bacteria and/or from the inhibition of the enzymatic reaction on the
chemistry strip if the urine is cold
Hemolysis Increases as a result of the deterioration of the erythrocytes in alkaline or dilute urine blood
Ketones May decrease with the presence of bacterial metabolism and volatilization of acetone
Leukocytes Decrease with alkalization and/or dilution of urine, or freezing
Nitrites Increase when bacteria convert nitrate to nitrite
Decrease when nitrite is converted to nitrogen and evaporates
Odor Becomes stronger from the ammonia produced from bacterial metabolism
pH Usually increases (alkaline) with the presence of urease-producing bacteria and/or the loss of carbon
dioxide
Decreases (acidic) with the proliferation of non–urease-producing bacteria and yeasts converting
glucose to acids
Proteins Increase from bacteria proliferation, alkalization, contamination with chemicals (e.g., disinfectants:
quaternary ammonium or chlorhexidine), some medications (check package insert), blood substitutes,
anesthetics, or elevated body temperature
Decrease with acidic urine
Turbidity Develops from presence of bacteria, proliferation of crystals, or precipitation of amorphous material
Somatic cells Deteriorate with rise in pH or freezing
Urobilinogen Decreases on exposure to light
Yeasts/fungi Increase from external contamination or resistant urinary tract infection
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![28 PART l Anatomy and Veterinary Diagnostics
6. Oliguria: a decrease in the formation or elimi-
nation of urine
a. Occurs with shock, dehydration, water con-
servation, renal failure, and insufficiency
7. Pollakiuria: refers to frequent urination
a. Often confused with polyuria by clients
8. Polyuria: formation and excretion of large vol-
umes of urine
a. Associated with nephritis, diabetes mellitus,
and polydipsia; may be an unreliable symp-
tom in itself
B. Volume: influenced by several factors, including
water intake, environmental temperature, physical
activity, size, species, diet, and medications
C. Ideally, various sequential samples should be evalu-
ated over 24 hours to determine the various inter-
nal and external influences on urine volume and the
other physical, chemical, and microscopic analytes
D. Color
1. In most species, although urine is regarded as
“yellow,”it may range in color from pale to am-
ber colored
a. Yellow is normally due to urochrome
pigments
b. Urobilinogen may also influence the color
2. Color generally correlates with SG (concentra-
tion), volume, and pigments from internal or
external sources
a. Light-colored urine tends to have a lower
SG; darker urine generally has a higher SG
b. Bile pigments are likely contained in yellow-
brown to greenish urine that foams when
shaken
c. Red or reddish-brown urine indicates hema-
turia (red blood cells [RBCs]) or hemoglo-
binuria (hemoglobin [Hb])
d. Brown urine may contain myoglobin from
muscle cell breakdown (myoglobinuria)
e. Medications and diet may influence color
f. Increase in urine volume results in urine di-
lution and lighter color
g. Urine collected after a period of rest tends
to be darker in color because of increased
concentration
3. Some species have variable color of urine
a. Rabbit urine commonly varies from yellow
to cloudy-white to orange-red-brown due to
porphyria pigments
b. Horse urine is browner on standing due to
oxidation
E. Transparency (turbidity, cloudiness): presence of
particulate matter
1. Transparency is described as clear, hazy, cloudy,
turbid, opaque, or flocculent (large particulate
matter that readily settles out)
2. Cloudy urine can be associated with the pres-
ence of cellular debris, such as RBCs, white
blood cells (WBCs), epithelial cells, crystals,
bacteria, casts, mucus, semen, and lipids
a. Bacterial proliferation or crystal forma-
tion can cause urine to become cloudy on
standing
3. Normal freshly voided urine in many species is
clear; exceptions include:
a. Horse, because of the presence of calcium
carbonate crystals and mucus secreted by
glands in the renal pelvis
b. Rabbit, hamster, and guinea pig, because of
the presence of calcium salts
c. Feline urine commonly is slightly cloudy,
because of the presence of fat
d. On standing, urine typically becomes more
cloudy with the increased number of bacte-
ria and possible formation of crystals (e.g.,
calcium carbonate crystals form in cattle
urine)
4. Microscopic evaluation is necessary to distin-
guish possible causes of turbidity
III. Odor
A. Not highly diagnostic; varies with species and gen-
der of the patient
1. Odors are commonly described as
a. “Normal” (characteristic for the species and
gender)
b. Ammoniacal (urease-producing bacteria)
c. Putrid (bacterial degradation of protein)
d. Fruity or sweet (e.g., ketones, glucose)
e. “Disagreeable”
2. Strong urine odor is typical in mice and intact
male cats, goats, and pigs
3. In some cases, a sweet or fruity odor can in-
dicate the presence of ketones (ketonuria) and
is commonly associated with diabetes mellitus,
pregnancy toxemia in sheep, or acetonemia
(ketosis) in cows
4. Ammonia is due to bacterial proliferation,
which may be from infectious or contaminat-
ing organisms, and will result in increased odor
on standing
a. It may be indicative of improper storage
rather than the health of the patient
5. Odormaybeinfluencedbydietandmedications
IV. Specific gravity (SG, urine specific gravity [USG])
A. Density of a liquid compared with that of distilled
water
1. In practical applications, it is used to assess
the ability of the renal tubule to concentrate
or dilute filtrates from the glomerulus, indi-
cating how well the kidney can maintain water
and osmotic balance
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![Chapter 2 Urinalysis and Hematology 29
2. The urine SG is interpreted by the veterinarian in
concert with the patient’s hydration status, and
blood urea nitrogen and serum creatinine levels
3. Urine density decreases as temperatures increases
4. Urine temperature is a factor when measuring SG
B. Terms related to SG
1. -sthen (strength), iso- (the same as), hypo- (less
than), hyper- (greater than)
2. Isosthenuria (“fixed SG” [SG ~1.008 to 1.012])
a. The glomerular filtrate has the same SG as
the plasma. The urine has been neither di-
luted nor concentrated in the renal tubules
3. Hyposthenuria (SG~1.008)
a. Tubules are diluting the urine below the SG
of plasma
b. Osmolality measurement is less than that of
plasma
4. Hypersthenuria (baruria [SG~1.012])
a. Tubules are concentrating the urine above
the SG of plasma
b. Osmolality measurement is more than that
of plasma
5. Maximum urine concentration (SG) values
a. Species-specific maximum concentration
capacity of the tubules
6. Functionally adequate urine concentration
(SG) values
a. Species-specific sufficient concentrating
ability, suggesting a sufficient number of
“normally”functioning nephrons to prevent
azotemia (presence of nitrogen wastes [e.g.,
urea, creatinine] in the blood) assuming re-
nal blood flow is sufficient and there are no
other influencing factors to impair the func-
tion of the nephrons
7. Inappropriate urine concentration (SG) values
a. Values below the questionable range
8. Questionable SG values
a. Values marginally below the functionally ad-
equate range
C. Normal (reference) SG values vary and fluctuate
widely from day to day and within the same day
and are related to the individual, species, diet, ac-
tivity, water, and electrolyte balance of the body, as
well as possible pathologies
1. A single value within the normal or outside the
normal range for an individual or the species
does not necessarily reflect renal function or
dysfunction
D. Methods of SG evaluation
1. Refractometer (total solids [TS] meter)
a. Solute in the urine bends light pass-
ing through the urine to a degree that is
proportional to the concentration of the
solute
b. Approximately measures SG or total solids
of urine
c. Refractometers are calibrated within a spe-
cific temperature range; operating outside
of this range may cause erroneous results;
check manufacturer’s instructions
d. Ensure that results are read from the SG
scale, which differs by species, and from the
total protein and refractive index scales
e. To approximate the SG if the reading is off
the scale; dilute the urine 1:1 with distilled
water and adjust results accordingly by mul-
tiplying the last two digits of the reading by 2
(1) For example, a urine sample diluted 1:1
with distilled water with a reading of
1.030 will have a SG of 1.060 (2×30)
when adjusted for the 1:1 dilution. Do
not attempt to make the dilution on the
refractometer, because of the difficulty
of obtaining an even mixture of urine
and distilled water
f. The relative specific refractivity of the urine
of cats, rabbits, and guinea pigs differs from
that of dogs, large animals, and humans
(1) Therefore the commonly used human-
based urine SG scale will give falsely el-
evated SG results for cats and falsely low
SG results for guinea pigs and rabbits
(2) Preferably, use refractometers with
scales calibrated for the specific species
g. Glucose, protein (albumin), radiopaque
dyes, urea, sodium chloride, and some an-
tibiotics will raise the SG value (e.g., ~0.004
for each gram of glucose per deciliter of
urine, and ~0.003 for each gram of protein
per deciliter of urine)
(1) To correct the SG, subtract the relevant
increase for each gram of analyte (e.g.,
protein or glucose) per deciliter of urine
h. Quality control: check the zero setting/cali-
bration of the refractometer daily with dis-
tilled water (1.000 SG [±0.05%]) and with
a known control (5% NaCl solution=1.022
SG [±0.001])
(1) Adjust refractometer according to man-
ufacturer’s instructions
2. Urinometer
a. A “hydrometer” calibrated for urine
b. When the urinometer is placed in a cylinder
filled with urine, it will displace a volume
equal to its weight
(1) Therefore the more solute present in the
urine, the less volume will be displaced
and the higher the urinometer will float,
denoting a higher SG
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![30 PART l Anatomy and Veterinary Diagnostics
c. Requires a large volume of urine (~5 to 15+
mL), whereas the refractometer requires
only a drop or two
d. Read results at bottom of the meniscus on
the urinometer float
e. Urinometer is calibrated to read samples
at room temperature; correct the SG read-
ing for the urine if the temperature of the
urine is not at the calibrated temperature
of the urinometer. Check manufacturer’s
instructions
f. Quality control
(1) Check the accuracy of the urinometer
with distilled water (SG 1.000) at the
calibrated temperature
3. SG reagent test strips
a. An indirect colorimetric method in which
an increased color change is correlated with
increased concentration of ionic solutes
b. Developed for use with human urine samples
c. Least reliable method of determining SG
in animals, especially if SG is greater than
1.030, the upper limit of the test strips
(1) High concentrations of protein or ke-
tones may give falsely elevated values,
whereas alkaline or dilute urine (low
SG) may give false low values and high
urine lipid content may either raise or
lower values
d. Not influenced by the presence of glucose or
urea
(1) Read results by comparing color changes
with color scale on container
e. See specific manufacturer’s instructions
4. Osmometry
a. Unit: milliosmol/kg [L]=mOsm/kg [L]
b. Likely the most representative method of an-
alyzing urine solute osmolar concentration
c. Measures number of dissolved particles in
the urine
(1) Costly instrumentation (osmometers)
and time-consuming method, therefore
more likely used in research and refer-
ence laboratories
d. Urine osmolality can be roughly “guessti-
mated”from the USG by multiplying the last
two digits of the urine SG (USG) by 36 (e.g.,
USG: 1.030≅1080 [30×36] mOsm/kg [L])
E. Urine SG values
1. Commonly reported SG values (Table 2-2)
2. Increased SG occurs with dehydration, de-
creased water intake, acute renal disease, and
shock
a. In these situations, it would be expected
that SG would be consistently higher than
~1.035 in the feline, 1.030 in the canine, and
1.025 in large animals
b. Decreased SG occurs with increased fluid in-
take and in renal and other diseases
Chemical Components
I. Urine pH
A. Used togenerallyassessthe body’sacid-basebalance
1. pH number expresses the hydrogen ion (H+
)
concentration or the acidity
a. pH 7 is decreased pH, or acid urine
b. pH 7 is increased pH, or basic or alkaline
urine
B. Reagent strips are most commonly used to deter-
mine pH; after being dipped into urine sample,
the color change is compared with the color on a
scale on the container
1. Common findings are between pH5.5 and 8.5
across species
C. pH is often affected by diet
1. Herbivores commonly have an alkaline pH (~7
to 8.5); nursing herbivores commonly have
more acid urine
2. Carnivores have an acidic pH (e.g., feline ~6
to 7)
3. Urine of omnivores may be either acidic or
basic
4. Urine tends to become less acid after meals, be-
cause of the “alkaline tide” (postprandial gas-
tric secretion of hydrochloric acid)
D. Loss of carbon dioxide occurs when samples are
left open and standing at room temperature, re-
sulting in higher pH readings
TABLE 2-2 Commonly Reported Specific Gravity Values
Species Approximate possible
maximum range
Common (daily
variable-functional) range
Questionable (marginal)
to adequate values*
Canine ~1.001-1.075 ~≥1.015-1.045 ~1.0301.040+
Feline ~1.001-1.085 ~≥1.035-1.060 ~1.0351.045+
Large animals ~1.001-1.040 ~≥1.015-1.030 ~1.025+
*Consistent successive results at the low end of or below these values from samples collected at various times throughout the day may indicate a disorder and would most
likely be considered an “inappropriate” value.
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![Chapter 2 Urinalysis and Hematology 31
E. Standing urine, containing urease-producing bac-
teria, also increases the reading
F. In highly acidic urine, a false reduction of the pH
reading may result because of dripping from the
protein pad onto the pH pad. Therefore technique
and timing are critical. See package insert
II. Protein:
A. Proteinuria usually describes an abnormal level of
proteins or protein metabolites in the urine
1. Important indicator of renal diseases such as
glomerulonephritis, amyloidosis, and nephrosis
2. When coupled with presence of renal casts may
indicate renal disease
B. Small amounts of protein pass through the glom-
erulus, but most are resorbed by the renal tubules
C. Detection of protein levels is commonly made
with a reagent test strip that generates a color
comparison. Results are recorded as milligrams
per deciliter of protein detected
1. Lower limits of detection: ~30 to 50mg/
dL; which is specific for relatively increased
amounts of albumin
D. The results for the healthy patient are none or
trace (10mg/dL), and the veterinarian will inter-
pret the protein results in concert with the urine
E. Results are considered semi-quantitative because
of variables in chemical reaction and color chart
comparison
F. Errors can occur
1. False-positive or falsely elevated values may
result when the urine is alkaline and highly
concentrated, if the test strip is left in contact
with the urine for an extended period, or if not
read at the appropriate time; check the package
insert
a. False-negative results can occur if protein-
uria is caused by globulins, or Bence-Jones
protein (indicative of multiple myeloma)
rather than albumin, or if protein is present
in dilute or acidic urine
2. Depending on the reader and individuality in
color determination, different values may be
obtained
3. Proteinuria in diluted urine indicates greater
protein loss than in concentrated urine
4. Small amounts of albumin may go undetected
with routine chemistry dipstick tests
G. Proteinuria results from several pre-renal and
post-renal causes
H. Values must be taken in context with hematology
and chemistry results, other urinalysis results, or
other methods of evaluating protein levels
1. Urine protein–to–creatinine (UPC) ratio
(lower limits of detection: ~≥5 mg/dL) reflects
the amount of protein excreted over 24 hours
based on a single urine sample
2. Sulfosalicylic acid turbidometric test (lower
limits of detection: ~≥5 to 10 mg/dL)
a. Detects globulins and Bence-Jones protein
in addition to albumins
b. Used as a confirmatory test for chemistry
test strip positive results, especially samples
with an alkaline pH
3. Micro albumin test (lower limits of detection:
~≥1 mg/dL); detects small quantities of albu-
min in the urine
a. Micro albumin level has been associated
with a variety of non-renal and renal dis-
eases, including being an indicator of early
glomerular renal disease
b. The full extent of the usefulness of this test is
still under study
c. Currently, the available efficacious tests in
veterinary medicine are species-specific im-
munological (enzyme linked immunosor-
bent assay [ELISA]) tests
(1) Human MA test strips do not com-
pletely match the results of the species-
specific veterinary tests
III. Glucose
A. Detectable levels of sugar are referred to as
glycosuria and depend on glucose levels in the
blood
1. Glucose is not commonly detected in
healthy animals; it passes through the glom-
erulus and is resorbed in the proximal renal
tubules
a. Unless the renal threshold is reached (e.g.,
~170 to 180 mg/dL [6.8 mmol/L] in dogs),
glycosuria does not usually occur
b. Therefore, unless there is excess of glucose
reaching the tubules that cannot be resorbed
or there is a functional deficit of the tubules,
glucose will not be detectable
B. Testing is usually performed with reagent test
strips to detect glucose, and/or reagent tablets to
detect sugars (glucose and other reducing sugars)
in the urine
1. If the proteinaceous labile enzymes found in
the glucose test pads become inactive, a false-
negative result occurs
C. Check with the manufacturer for details on pro-
longing the life of unopened, in-date packages by
freezing
D. Hyperglycemia along with glucosuria can be at-
tributed to diabetes mellitus created by insulin
deficiency or function
1. For confirmation of diabetes mellitus, blood
glucose level should be evaluated
E. Other factors, such as fear, stress, excitement, in-
travenous infusion of glucose, and other diseases
also cause glycosuria
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![32 PART l Anatomy and Veterinary Diagnostics
1. Fasting is recommended before glucose testing
to avoid higher levels after a high-carbohydrate
meal
a. False-positive results can occur after the use
of various drugs, such as salicylates, ascorbic
acid, and penicillin
IV. Ketones
A. Any compound containing a carbonyl group and
carbon monoxide and having a carbonyl group
containing a chain of carbon atoms
1. Ketone bodies include acetone, acetoacetic
acid, and β-hydroxybutyric acid
a. Acetone and β-hydroxybutyric acid are de-
rived from acetoacetic acid and result from
the catabolism of fatty acid
b. Usually, ketones are filtered by the glomeru-
lus and reabsorbed by the tubules
c. Ketones are produced during fat metabo-
lism and are important sources of energy
d. Excessive ketones are toxic, producing
central nervous system depression and
acidosis
B. In normal animals, very small amounts are found
in the blood
1. If there is increased fat metabolism, excess ke-
tones spill into the urine, causing ketonuria
2. Ketonuria may occur as a result of incomplete
reabsorption by the proximal renal tubules
3. Ketonemia (excess ketones in circulation [keto-
sis, acetonemia]) results in ketonuria
C. Commonly, in large animals, ketosis (pregnancy
toxemia) is associated with hypoglycemia conse-
quential to high glucose demands, resulting in in-
creased fat metabolism
1. Typically occurs in early lactation or late preg-
nancy, whereas in small animals, ketosis occurs
with diabetes mellitus; lack of insulin prevents
carbohydrate utilization
D. Several reagent test strips or separate reagent tab-
lets can be used to measure ketone levels
1. Color intensity is proportional to ketone
concentration
2. These tests are most sensitive to acetoacetic
acid and acetone
V. Bile pigments
A. Commonly detected bile pigments include biliru-
bin and urobilinogen
1. Only conjugated bilirubin is found in the urine
2. A small amount of urobilinogen, from the
breakdown of bilirubin (as a result of hemo-
globin breakdown) by bacteria in the intestines,
is excreted into the urine
3. Excessive quantities of bilirubin is known as
urobilinuria or bilirubinuria
B. Determination of bile pigments is made with re-
agent test strips and tablet tests, with the tablet
tests being more accurate
1. A rough determination of the presence of
bilirubinuria can be determined if urine is
shaken and a yellow foam forms
2. Positive bilirubin test pads in cats are usually
reliable, whereas in dogs there can be a signifi-
cant number of false-negative and false-positive
results
a. Urobilinogen is not easily detected; there-
fore urobilinogen test pads in both dogs and
cats have not been always reliable
C. Bilirubinuria can be seen in several diseases, in-
cluding biliary obstruction, hepatic infections,
toxicity, and hemolytic anemia
1. Light will oxidize bilirubin if urine is left stand-
ing, resulting in a false-negative result
2. Because the liver and kidneys of dogs and cattle
have an enzyme that can conjugate bilirubin,
slight bilirubinuria may be normally present in
these species
VI. Blood
A. Presence of intact RBCs in the urine is referred to
as hematuria, whereas the presence of free hemo-
globin is hemoglobinuria and presence of myoglo-
bin is myoglobinuria
1. Hematuria, hemoglobinuria, and myoglobin-
uria change the color of urine from pink to red
to brown
a. A crude method to distinguish between
myoglobinuria and hemoglobinuria is to
evaluate the plasma/serum for the presence
of hemolysis
(1) If the urine and plasma/serum are fresh
and both are reddish, hematuria is most
likely present
(2) Colorless plasma is indicative of myo-
globinuria, because myoglobin does not
emit a color in the plasma
(3) Myoglobinuria is accompanied by
intact red blood cells; an elevated
plasma/serum creatine kinase (CK)
may also suggest the possibility of
myoglobin in the urine, because an
increase in both may indicate insult to
muscle tissue
(4) In severe cases, urine may be almost
black
b. To distinguish hematuria from hemoglobin-
uria and myoglobinuria
(1) Pre-centrifugation:with hematuria,urine
is cloudy because of the presence of intact
erythrocytes
(2) Post-centrifugation of the urine
c. The supernatant will remain colorless in the
case of hematuria
d. If hemoglobinuria and myoglobinuria are
present, the urine supernatant will still be
reddish
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![Chapter 2 Urinalysis and Hematology 33
B. Occult blood may also be present, with no visible
changes to the urine
C. Hematuria is associated with disease of the uro-
genital tract
1. Hemoglobinuria indicates some intravascular
hemolysis
a. Caution: post collection hemolysis occurs
with improperly handled or stored urine
2. Myoglobinuria generally indicates a pathologi-
cal condition of muscle or overexertion
D. Besides color interpretation, blood or blood com-
ponents in the urine are detected with reagent
strips as well as tablets
1. Because these do not differentiate the cause of
blood in urine, microscopic evaluation to de-
termine RBC number, animal history and ex-
amination, and other tests should be included
in the evaluation process
VII. Nitrite level in urine in humans is used as an indirect
indication of bacteruria
A. It is believed that ascorbic acid normally presents
in canine and feline urine and usually gives false-
negative results
B. Bacterial cultures and microscopic evaluation of
fresh urine samples are the best methods for de-
tecting the presence of bacteriuria
VIII. Leukocyte tests are designed to detect the presence of
leukocyte esterase, found in all types of white blood
cells, except lymphocytes
A. False-positive results for cats and false-negative
results for dogs are common; therefore it is best
to evaluate fresh urine samples microscopically for
the presence of leukocytes
B. In addition, false-negative results may occur in pa-
tientswithglycosuriaandelevatedUSG,andinthose
treated with certain antibiotics (e.g., tetracycline)
C. Falsely elevated results have been observed in old
samples and those contaminated with feces
D. Check package insert
IX. Urobilinogen is formed in the gastrointestinal (GI)
tract by anaerobic bacteria breaking down conjugated
bilirubin, with small amounts eliminated in the urine
and the majority in the feces
A. When elevated, the test may be indicative of liver
or GI tract dysfunction or intravascular hemolysis
1. Because of the instability of urobilinogen, false-
negative results have been observed in acidic
urine, old samples, and those exposed to light
and air
2. False-positive results have been observed when
the reagent strips have been stored close to a
heat source
3. Unlike in humans, a significantly increased
urobilinogen level with the chemistry dip-
stick has not been observed in most patients;
therefore the usefulness of the test in animals is
questionable
Microscopic Evaluation
Examination of the urine sediment is highly valuable when
used with the urine physical and chemistry tests, and he-
matology and serum/plasma chemistries. Microscopic
evaluation may be considered a form of exfoliate cytology.
I. Sample preparation
A. Best sample is obtained after a period of extended
rest,becauseitismorelikelytobehighlyconcentrated
B. Refrigerate the sample if it cannot be examined
within 20 to 30 minutes. Room temperature stor-
age can result in bacterial growth, natural chemi-
cal breakdown, and cell lysis
C. Thoroughly mix the specimen, transfer to a conical-
tipcentrifugetube,andcentrifugesampleatthespeed
and time specified by the centrifuge manufacturer
1. At least 5mL fresh urine is ideal,but“micro”meth-
odsandcontainersareavailableforsmallersamples
D. Notethevolumeof sediment;leaveasmallamountof
the supernatant and resuspend the sediment by gen-
tly tapping the bottom of the tube with your finger
1. Using a pipette, transfer a small drop of urine to
a clean microscope slide and examine (Note: Do
not use a wooden stick, because cells and other
constituents commonly adhere to the stick)
a. Cover-slipping is optional, based on experi-
ence and personal preference
b. Viewing of stained (e.g., wet: Sternheimer-
Malbin, 0.5% new methylene blue [NMB])
or unstained urine is based on experience
and personal preference
(1) If staining is done, do not attempt to
mix the stain on the slide with the urine.
Mix in the tube for the best suspension
of stain and urine
(2) The type of stain will specifically influ-
ence the appearance of the microscopic
elements. Use an unstained sample to
distinguish between stain artifacts and
urine constituents (Figure 2-1)
(3) Diff-Quik also can be used for stained
urine preparation, with films prepared
in methods similar to blood and other
cytology films. Because urine is a fluid
with typically low protein content, it
may be washed off the slide in the stain-
ing process. Use of serum-coated slides
may limit the loss of supernatant
E. Reduce illumination (lower condenser), view en-
tire area under the coverslip through a 10× (low
power field [LPF]) objective and then through a
40× (high power field [HPF]) objective
F. Crystals and cast numbers are typically estimated
as the average number per LPF
1. Epithelial cells and blood cells are estimated as
the average number per HPF
2. Bacteria and sperm are noted as few, moderate,
or many under HPF
VetBooks.ir](https://image.slidesharecdn.com/31296-250526193438-2910a87c/85/Mosby-s-Comprehensive-Review-for-Veterinary-Technicians-4th-Edition-Monica-M-Tighe-Marg-Brown-44-320.jpg)
![blow. He was more than pleased when I gave him his freedom, and
he never evinced any further desire to fight me.
It's easy for anyone to thrash poor Carroty, said Joe, when I had
finished the battle.
On Sunday we got drunk together in a speak-easy[8] near the
model, and it was with difficulty that we restrained Carroty from
challenging everybody whom he met to fistic encounter. By nightfall
Moleskin counted his money, and found that he had fourpence
remaining.
I'm off to Kinlochleven in the morning, he said. There's good graft
and good pay for a man in Kinlochleven now. I'm sick of prokin' in
the gutters here. Damn it all! who's goin' with me?
I'm with you, gibbered Carroty, running his fingers through the
blazing torch—the term used by Joe when speaking of the red hair
of his mate.
I'll go too, I said impulsively. I've only twopence left for the
journey, though.
Never mind that, said Moleskin absently. There's a good time
comin'.
Kinlochleven is situated in the wilderness of the Scottish Highlands,
and I had often heard of the great job going on there, and in which
thousands of navvies were employed. It was said that the pay was
good and the work easy. That night I slept little, and when I slept
my dreams were of the journey before me at dawn, and the new
adventures which might be met with on the way.](https://image.slidesharecdn.com/31296-250526193438-2910a87c/85/Mosby-s-Comprehensive-Review-for-Veterinary-Technicians-4th-Edition-Monica-M-Tighe-Marg-Brown-63-320.jpg)
![FOOTNOTE:
[8] A shebeen. You must speak easy in a shebeen when the police
are around.](https://image.slidesharecdn.com/31296-250526193438-2910a87c/85/Mosby-s-Comprehensive-Review-for-Veterinary-Technicians-4th-Edition-Monica-M-Tighe-Marg-Brown-64-320.jpg)
![What happened to the other two slices? I asked.
I gave it to a woman who was hungrier than myself, said Joe
simply.
We sat in a nice cosy place. Beside us rumbled a little stream; it
glanced like anything as it ran over the stones and fine sands in its
bed. From where we sat we could see it break in small ripples
against the wild iris and green rushes on the bank. From above, the
gold of the sunlight filtered through the waving leaves and played at
hide and seek all over our muck-red moleskin trousers. Far down an
osier bed covered the stream and hid it from our sight. From there a
few birds flew swiftly and perched on the tree above our heads and
began to examine us closely. Finding that we meant to do them no
harm, and observing that Moleskin threw away little scraps which
might be eatable, one bold little beggar came down, and with legs
wide apart stood a short distance away and surveyed us narrowly.
Soon it began to pick up the crumbs, and by-and-bye we had a
score of strangers at our meal.
Later we lay on our backs and smoked. 'Twas good to watch the
blue of the sky outside the line of leaves that shaded us from the
sun. The feeling of rest and ease was sublime. The birds consumed
every crumb which had been thrown to them; then they flew away
and left us. When our pipes were finished we washed our feet in the
passing stream, and this gave us great relief. Moleskin pared a corn;
I turned my socks inside out and hit down a nail which had come
through the sole of my bluchers, using a stone for a hammer.
Now we'll get along, Moleskin, I said, for I was in a hurry.
Along be damned! cried my mate. I'm goin' to have my dog-
sleep.[9]
You have eaten, I said, and you do not need your dog-sleep to-
day.](https://image.slidesharecdn.com/31296-250526193438-2910a87c/85/Mosby-s-Comprehensive-Review-for-Veterinary-Technicians-4th-Edition-Monica-M-Tighe-Marg-Brown-70-320.jpg)
![From experience I knew this to be the case; so together we broke
rotten hazel twigs, collected some dry brambles from the
undergrowth and built them in a heap. Joe placed some crisp moss
under the pile; I applied a match and in a moment we had a brightly
blazing fire. I emptied my pockets, proud to display the results of
the afternoon's work, which, when totalled, consisted of four slices
of bread, twopence, and about one half-ounce of tobacco. Joe
produced some more bread, his penny, and three little packets which
contained tea, sugar, and salt. These, he told me, he had procured
from a young girl in a ploughman's cottage.
But the hen, Moleskin—where did you get that? I asked, when I
had gathered in some extra wood for the fire.
On the king's highway, Flynn, he added with a touch of pardonable
pride. Coaxed it near me with crumbs until I nabbed it. It made an
awful fuss when I was wringing its neck, but no one turned up, more
by good luck than anything else. I never caught any hen that made
such a noise in all my life before.
You are used to it then! I exclaimed.
Of course I am, was the answer. When you are on the road as
long as I've been on it, you'll be as big a belly-thief[10] as myself.
It was fine to look around as the sun went down. Far west the sky
was a dark red, the colour of old wine. A pale moon had stolen up
the eastern sky, and it hung by its horn from the blue above us.
Looking up at it, my thoughts turned to home, and I wondered what
my own people would say if they saw me out here on the ghostly
moor along with old Moleskin.
I searched around for water, and found a little well with the moon at
the bottom. As I bent closer the moon disappeared, and I could see
the white sand beneath. I thought that the well was very holy, it
looked so peaceful and calm out there alone in the wild place. I said
to myself, Has anybody ever seen it before? What purpose does it
serve here? I filled the billies, and when turning away I noticed that](https://image.slidesharecdn.com/31296-250526193438-2910a87c/85/Mosby-s-Comprehensive-Review-for-Veterinary-Technicians-4th-Edition-Monica-M-Tighe-Marg-Brown-73-320.jpg)
![snow on the ground when he left our shack in the evenin', and no
sooner were his heels out of sight than a blizzard came on. You
know Toward Mountain, Flynn? Yes. Well, it is seven long miles from
the top of the hill to the nearest town. Devaney never finished his
journey. We found him when the thaw came on, and he was lyin'
stiff as a bone in a heap of snow. And them hooded crows! There
was dozens of them pickin' the flesh from his naked shoulder-blades.
They had eat the very guts clean out of Red Muck, so we had to
bury him as naked as a newborn baby. By God! Flynn, they're one of
the things that I am afraid of in this world, them same hooded
crows. Just think of it! maybe that one that I just threw the stone at
was one of them as gobbled up the flesh of Muck Devaney.
FOOTNOTES:
[9] A sleep on an empty stomach in the full sun.
[10] One who steals to satisfy his hunger.](https://image.slidesharecdn.com/31296-250526193438-2910a87c/85/Mosby-s-Comprehensive-Review-for-Veterinary-Technicians-4th-Edition-Monica-M-Tighe-Marg-Brown-80-320.jpg)
Mosby s Comprehensive Review for Veterinary Technicians 4th Edition Monica M Tighe Marg Brown
- 1. Mosby s Comprehensive Review for Veterinary Technicians 4th Edition Monica M Tighe Marg Brown install download https://ebookmeta.com/product/mosby-s-comprehensive-review-for- veterinary-technicians-4th-edition-monica-m-tighe-marg-brown/ Download more ebook from https://ebookmeta.com
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- 3. * Evolve Student Resources are provided free with each NEW book purchase only. YOU’VE JUST PURCHASED MORE THAN A TEXTBOOK!* FPO: Peel Off Sticker You can now purchase Elsevier products on Evolve! Go to evolve.elsevier.com/html/shop-promo.html to search and browse for products. Evolve Student Resources for Tighe: Mosby's Comprehensive Review for Veterinary Technicians, 4th edition, include the following: • Database of more than 500 examination questions • Ability to create unique practice tests from the database questions • Clock functionality to practice time management • Image collection, including additional images to further clarify key concepts • Appendices that include abbreviations and symbols, the metric system and equivalents, medical terminology, species names, normal values, and additional veterinary technician resources Activate the complete learning experience that comes with each NEW textbook purchase by registering with your scratch-off access code at http://evolve.elsevier.com/Tighe/Brown/ If you purchased a used book and the scratch-off code at right has already been revealed, the code may have been used and cannot be re-used for registration. To purchase a new code to access these valuable study resources, simply follow the link above. REGISTER TODAY! VetBooks.ir
- 4. Monica M. Tighe, RVT, BA, MEd Veterinary Technician Program St. Clair College Windsor, Ontario Marg Brown, RVT, BEd Ad Ed Penn Foster College Scranton, Pennsylvania Formerly of Seneca College King City, Ontario VetBooks.ir
- 5. 3251 Riverport Lane St. Louis, Missouri 63043 MOSBY’S COMPREHENSIVE REVIEW FOR VETERINARY TECHNICIANS, FOURTH EDITION ISBN: 978-0-323-17138-0 Copyright © 2015 by Mosby, an imprint of Elsevier Inc. Copyright © 2008, 2003, 1998 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Library of Congress Cataloging-in-Publication Data Mosby’s comprehensive review for veterinary technicians / Monica M. Tighe, Marg Brown. – Fourth edition. p. ; cm. Comprehensive review for veterinary technicians Includes bibliographical references and index. ISBN 978-0-323-17138-0 (pbk. : alk. paper) 1. Animal health technology. I. Tighe, Monica M., editor. II. Brown, Marg, editor. III. Title: Comprehensive review for veterinary technicians. [DNLM: 1. Veterinary Medicine–methods–Examination Questions. 2. Veterinary Medicine–methods– Outlines. 3. Animal Technicians–Examination Questions. 4. Animal Technicians–Outlines. SF 774.4] SF774.4.M67 2015 636.089073'7069--dc23 2014016500 Content Strategy Director: Penny Rudolph Content Manager: Shelly Stringer Publishing Services Manager: Jeff Patterson Senior Project Manager: Anne Konopka Design Direction: Maggie Reid Printed in China Last digit is the print number: 9 8 7 6 5 4 3 2 1 NOTICES Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treat- ment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of the practitioners, relying on their own experience and knowledge of the patient, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors assume any liability for any injury and/or damage to persons or property as a matter of products’ liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. VetBooks.ir
- 6. Chapter 11 Pharmacology v To all past, present, and future veterinary technology students: May you derive satisfaction from your chosen career every single day. To all of our family, friends, and co-workers: We cherish and treasure your constant support. Thank you. Marg Brown and Monica M. Tighe Happy 89th Birthday RT! MMT Jacquie and Phil—Love always MB VetBooks.ir
- 7. CONTRIBUTORS Carolyn Bennett, AHT Diagnostic Imaging OVC Health Sciences Centre University of Guelph Guelph, Ontario Alternative Imaging Technology Sarah Birch, RVT Avian and Exotics Department OVC Health Sciences Centre University of Guelph Guelph, Ontario Exotic Animal Medicine Marg Brown, RVT, BEd Ad Ed Penn Foster College Scranton, Pennsylvania Formerly of Seneca College King City, Ontario Radiography Frances Cheslo, AHT, RVT Communications Supervisor Hill’s Pet Nutrition Canada Mississauga, Ontario Small Animal Nutrition Sue Cornwell, RVT Large Animal Clinic OVC Health Sciences Centre University of Guelph Guelph, Ontario Equine Nursing and Surgery Mary E. Fowler, RVT, RLAT Campus Animal Facilities Office of Research University of Guelph Guelph, Ontario Laboratory Animal Medicine Mary Ellen Goldberg, VMT, LVT, CVT, SRA, CCRA VetMedteam, LLC Faculty Mannheimer Foundation, Inc. Boynton Beach, Florida Pain Management Kim Healey, RVT Large Animal Clinic OVC Health Sciences Centre University of Guelph Guelph, Ontario Equine Nursing and Surgery Geraldine Higginson, BSc, MSc, RVT Animal Cancer Centre OVC Health Sciences Centre University of Guelph Guelph, Ontario Exotic Animal Medicine Alicea A. Howell, BS, RVT, VTS (Behavior), KPA CTP, CPDT KA Hillview Veterinary Clinic Franklin, Indiana Companion Animal Behavior Angela Kendall, RVT Alta Vista Animal Hospital Formerly at Algonquin College Ottawa, Ontario Sanitation, Sterilization, and Disinfection Susan MacNeal, RVT, CVDT, BSc Veterinary Technician Program Georgian College Orillia, Ontario Veterinary Dentistry Lori Renda-Francis, LVT, PhD Veterinary Technician Program Macomb Community College Macomb, Texas Personal, Practice, and Professional Management Skills and Ethics VetBooks.ir
- 8. Contributors v Ed Robinson, CVT, AAS, BA Shakespeare Veterinary Hospital Stratford, Connecticut Parasitology Morgan Rodgers, BS, AAS, CVT, MEd Pima Medical Institute Tucson, Arizona Animal Anatomy and Physiology Oreta M. Samples, RVT, MPH, DHSc Fort Valley State University Department of Veterinary Science Fort Valley, Georgia Urinalysis and Hematology Shirley Sandoval, BAS, LVT, VTS (LAIM) Comparative Theriogenology College of Veterinary Medicine Washington State University Pullman, Washington Large Animal Nursing, Surgery, and Anesthesia DeeDee Schumacher, CVT, VTS (ECC), MEd Veterinary Technology Program Des Moines Area Community College Ankeny, Iowa Emergency Medicine Jennifer Serling, CVT, BS, VSc Pima Medical Institute Tucson, Arizona Immunology and Virology Julie Singer, RVT, CVPM Board Moderator, CE Instructor, vspn.org Veterinary Support Personnel Network Davis, California Personal, Practice, and Professional Management Skills and Ethics Margi Sirois, EdD, MS, RVT Veterinary Technology Program Wright Career College Overland Park, Kansas Cytology Lucy Siydock, BSc(H), RVT, VTS (Anesthesiology) OVC Health Sciences Centre University of Guelph Guelph, Ontario Anesthesia Sandra Skeba, LVT Nashville Zoo at Grassmere Grassmere, Tennessee Diagnostic Microbiology and Mycology Teresa F. Sonsthagen, BS, LVT Veterinary Technology Program Department of Animal and Range Sciences North Dakota State University Fargo, North Dakota Restraint and Handling Marianne Tear, MS, LVT Veterinary Technology Program Baker College Clinton Township, Michigan Genetics, Theriogenology, and Neonatal Care Surgical Principles Monica M. Tighe, RVT, BA, MEd Veterinary Technician Program St. Clair College Windsor, Ontario Pharmaceutical Calculations Small Animal Nursing James A. Topel, CVT Veterinary Technician and Laboratory Animal Technician Programs Madison Technical College Madison, Wisconsin Large Animal Nutrition and Feeding Elizabeth Warren, RVT Health Professions Institute Austin Community College Austin, Texas Pharmacology Kisha White-Farrar, BS, RVT, RN Parkland Health and Hospital System Fort Worth, Texas Zoonoses Ann Wortinger, BIS, LVT, VTS (ECC, SAIM, Nutrition) Affiliated Veterinary Emergency Service, PC Allen Park, Michigan Clinical Chemistry VetBooks.ir
- 9. PREFACE Mosby’s Comprehensive Review for Veterinary Technicians, fourth edition, continues to be a reference book writ- ten by and for veterinary technicians. The format and layout of this concise text is not meant to extensively cover veterinary technology. Instead, the goal of this manual is to benefit technicians not only studying for national accreditation examinations, but also for students reviewing important facets of their education and for graduates in the field needing a quick reference. The new edition is now in full color, including more color images augmenting the text. A separate, well- described chapter on pain management has been added and explains the latest concepts in this area of study. The material in each chapter has been updated by experts in their field. The focus for this edition has been the CVTEA guidelines for the VTNE. Multiple-choice questions have been expanded, and the rationale has been included to assist the learner in understanding the information more fully. A new bank of 350 multiple-choice questions and rationales has been added to the text. As with previous editions, learning outcomes, an easy to follow numbered format, emphasis on the important components both academically and prac- tically, and inclusion of current extensive references add to the practicality of the text. Updated appendices include abbreviations, metric system, medical termi- nology, species names, normal values, and additional internet resources. Mosby’s Comprehensive Review for Veterinary Technicians, fourth edition, continues to be an excellent primary review guide that complements every veteri- nary technology textbook. EVOLVE WEBSITE New to this edition is an accompanying Evolve web- site available to instructors and students using Mosby’s Comprehensive Review for Veterinary Technicians. At the front of the book is a page introducing the Evolve web- site. All you need to get started is an internet connection. To register as a student or instructor, enter the following URL: http://evolve.elsevier.com/Tighe/Brown/. To better simulate the computer-based testing en- vironment, the Evolve site will host a comprehensive review examination including approximately 1000 questions. Students can study the questions by topic or randomize the questions. Rationales for each correct and incorrect answer will be provided. Students can re- view the question in a quiz mode or “sit” for a timed mock examination and receive a final score. These new features will give students the confidence and practice needed to master the VTNE. The Evolve website also features an image collection that contains all of the images from within the book plus additional images to further clarify key concepts. You will also find appendices that include important information such as abbreviations and symbols, met- ric system and equivalents, medical terminology, spe- cies names, normal values, and additional veterinary resources. ACKNOWLEDGMENTS We would like to thank our editor, Shelly Stringer, and the team at Elsevier, who continue to provide excellent resources to veterinary technicians. Special thanks and appreciation go to the authors of the various chapters, not only in this edition but also in the previous three. We enjoyed working with you! Your expertise, enthusiasm, and dedication have made this text a valuable asset to veterinary technicians. Monica M. Tighe and Marg Brown VetBooks.ir
- 10. CONTENTS PART I: Anatomy and Veterinary Diagnostics 1 Animal Anatomy and Physiology, 1 Morgan Rodgers 2 Urinalysis and Hematology, 24 Oreta M. Samples 3 Parasitology, 57 Ed Robinson 4 Clinical Chemistry, 82 Ann Wortinger 5 Cytology, 98 Margi Sirois 6 Diagnostic Microbiology and Mycology, 119 Sandra Skeba 7 Radiography, 135 Marg Brown 8 Alternative Imaging Technology, 172 Carolyn Bennett PART II: Patient Management 9 Immunology and Virology, 187 Jennifer Serling 10 Sanitation, Sterilization, and Disinfection, 205 Angela Kendall 11 Companion Animal Behavior, 216 Alicea A. Howell 12 Restraint and Handling, 229 Teresa F. Sonsthagen 13 Small Animal Nutrition, 254 Frances Cheslo 14 Large Animal Nutrition and Feeding, 277 James A. Topel 15 Genetics, Theriogenology, and Neonatal Care, 300 Marianne Tear 16 Laboratory Animal Medicine, 327 Mary E. Fowler 17 Exotic Animal Medicine, 356 Sarah Birch and Geraldine Higginson 18 Zoonoses, 385 Kisha White-Farrar PART III: Veterinary Therapeutics 19 Pharmacology, 404 Elizabeth Warren 20 Pharmaceutical Calculations, 431 Monica M. Tighe 21 Anesthesia, 438 Lucy Siydock 22 Pain Management, 473 Mary Ellen Goldberg 23 Surgical Principles, 500 Marianne Tear 24 Small Animal Nursing, 519 Monica M. Tighe 25 Equine Nursing and Surgery, 559 Sue Cornwell and Kim Healey 26 Large Animal Nursing, Surgery, and Anesthesia, 590 Shirley Sandoval 27 Emergency Medicine, 612 DeeDee Schumacher 28 Veterinary Dentistry, 628 Susan MacNeal PART IV: Professional Management 29 Personal, Practice, and Professional Management Skills and Ethics, 651 Lori Renda-Francis and Julie Singer Glossary 676 Appendix A Comprehensive Test with Answer Key, 706 Appendix B Chapter Reviews Answer Key, 729 VetBooks.ir
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- 12. 1 CHAPTER 1 PART I Anatomy and Veterinary Diagnostics Animal Anatomy and Physiology Morgan Rodgers CHAPTER CONTENTS Definitions Cell Structure and Physiology Prokaryote: “Before Nucleus” Eukaryote: “True Nucleus” Movement In and Out of Cells Tissues Epithelial Tissue Connective Tissue Muscle Tissue Nervous Tissue Membranes Directional Terminology Body Systems Skeletal System Muscular System Nervous System Cardiovascular System Central Vascular System Digestive System Lymphatic System Respiratory System Excretory System Reproductive System: Male Reproductive System: Female Endocrine System Integumentary System Senses Acknowledgment Review Questions Bibliography LEARNING OBJECTIVES After reading this chapter you should be able to: 1. Explain the various processes that enable substances to move in and out of cells. 2. List the structural and functional characteristics of the four primary body tissues and their subtypes. 3. Define and be able to use all directional terms. 4. Classify and identify basic bones and joints. 5. List the three types of muscle and state the distinct characteristics of each. 6. Describe the divisions of the nervous system and state how they relate to each other. 7. List the parts of the brain and state their functions. 8. List the parts of the cardiovascular system and state their functions. KEY TERMS anatomy apnea articulation canthi carnivore conjunctiva cornea coronary dead space dyspnea dystocia endocrine glands estrous cycle estrus eupnea exocrine glands extracellular herbivore homeostasis hormone hypertonic hypotonic intercellular intracellular isotonic lacrimal apparatus lactation laminae lumen meninges monestrous monotocous myocardium nonspontaneous ovulator omnivore osmotic pressure osteology parturition physiology polyestrous polytocous residual volume ruminant spontaneous ovulator tidal volume VetBooks.ir
- 13. 2 PART l Anatomy and Veterinary Diagnostics Anatomy and physiology are the essential foundations of veterinary technology. Many clinical procedures, such as positioning of a patient for a radiograph, preparing for a surgical procedure, or simply placing a catheter, in- volve a working knowledge of anatomy and physiology. Understanding the unique interrelationships of the ani- mal’s body systems is critical in assisting with the manage- ment of disease. DEFINITIONS I. Anatomy: the science of the structure of the body and the relation of its parts II. Physiology: the science of how the body functions CELL STRUCTURE AND PHYSIOLOGY Cells are the basic unit of life. Cells are either prokaryotes or eukaryotes. Prokaryote: “Before Nucleus” I. A cell that lacks a true membrane-bound nucleus and organelles II. All bacteria are prokaryotes Eukaryote: “True Nucleus” I. A cell that has a membrane-bound nucleus and con- tains many different membrane-bound organelles II. All multicellular organisms are composed of eukary- otic cells III. Composition of eukaryotic cells Three major parts: cell membrane, cytoplasm, and nucleus A. Cell membrane (plasma membrane) Separates the cell from its external environment 1. Consists of a double phospholipid layer with in- terspersed proteins (fluid-mosaic model); also contains carbohydrate chains and cholesterol 2. Semipermeable; therefore allows various sub- stances to move in and out of the cell 3. Some cells have surface modifications, such as hairlike projections (cilia) that are used for surface movement, a single longer projection (flagellum) that is used for cellular movement, or microvilli that increase surface area (especially in absorptive cells) B. Cytoplasm Encompasses everything within the cell except the nu- cleus. Organelles within the cytoplasm have very special- ized functions 1. Ribosomes a. Float freely or are attached to the endoplas- mic reticulum b. Composed of protein and ribosomal ribonu- cleic acid (RNA) c. Site of protein synthesis 2. Mitochondria a. “Powerhouse” of the cell b. Contains mitochondrial deoxyribonucleic acid (DNA) and protein c. Double membrane with the inner membrane extending into folds called cristae d. Cristae increase surface area for production of adenosine triphosphate (ATP) e. ATP is produced through the process of cel- lular respiration (Krebs cycle, citric acid cycle, tricarboxylic acid cycle) f. Cells that use large amounts of energy (e.g., skeletal muscle) have large numbers of mitochondria 3. Endoplasmic reticulum (ER) a. Rough endoplasmic reticulum (RER) (1) Hollow system of flattened membranous channels with attached ribosomes (2) Acts as transportation network for proteins b. Smooth endoplasmic reticulum (SER) (1) Hollow system of flattened membranous channels without attached ribosomes (2) Not involved in protein synthesis (3) Important in synthesizing cholesterol, steroid-based hormones, and lipids; also important in detoxification of drugs, breakdown of glycogen, and transporta- tion of fats 9. Explain the cardiac cycle and identify its components on a typical electrocardiogram. 10. Compare and contrast the structure and function of arteries and veins. 11. Explain the process of digestion. 12. Name the parts of the ruminant stomach and state their functions. 13. Describe the structure and function of lymph vessels, lymph nodes, and lymphatic organs. 14. Name the parts of the respiratory system and state their functions. 15. Describe the three basic processes of respiration. 16. Define tidal volume, residual volume, dead space, apnea, eupnea, and dyspnea. 17. Explain the anatomy and functions of the excretory system. 18. Explain the anatomy and physiology of the male and female reproductive systems. 19. Explain the estrous cycle. 20. Describe the processes of parturition and lactation. 21. List the endocrine glands; state the hormones they re- lease and their functions. 22. Describe the structure and function of all sense organs. VetBooks.ir
- 14. Chapter 1 Animal Anatomy and Physiology 3 (4) Liver cells, intestinal cells, and intersti- tial cells of the testes have large amounts of SER 4. Golgi complex (Golgi apparatus) a. Stacked, saucer-shaped membranes that function as a receiving, packaging, and distri- bution center b. Modifies and packages substances received from the ER and then exports them from the cell or releases them into the cytoplasm for internal use c. Produces lysosomes 5. Lysosomes a. Contain digestive enzymes that digest intra- cellular bacteria and break down nonfunc- tional organelles b. Are the principal organelles in digestion of nutrients c. Autolysis (i.e., self-digestion of the cell) oc- curs if the lysosome enzymes are released into cytoplasm d. Large numbers found in phagocytic cells 6. Peroxisomes a. Membrane-bound organelles that contain strong oxidase and catalase enzymes b. Use oxygen to detoxify toxic substances, espe- cially alcohol and formaldehyde c. Very important in converting free radicals (normal by-products of cellular metabo- lism but harmful to biological molecules if left to accumulate) into hydrogen perox- ide, which is converted to water by catalase enzymes d. Large numbers found in liver and kidney cells 7. Cytoskeleton a. Consists of microtubules, microfilaments, and intermediate filaments, which are all made of proteins b. Provides an elaborate internal framework that gives the cell form, structure, and support; anchors organelles; and enables movement 8. Centrioles a. Microtubules arranged to form a hollow tube b. Important in organizing the mitotic spindle c. Form the base of cilia and flagella C. Nucleus 1. Control center of the cell 2. Contains DNA, which governs heredity and pro- tein synthesis 3. DNA is in the form of chromatin in the nondi- viding cell and in the form of chromosomes in the dividing cell 4. Has a double, semipermeable nuclear membrane or envelope 5. Contains one or more nucleoli, which manufac- ture the ribosomal units MOVEMENT IN AND OUT OF CELLS I. Definitions A. Solute: a substance that can be dissolved B. Solvent: a substance that does the dissolving C. Solution:whenthesolutehasdissolvedandisnolonger distinguishable from the solvent (a uniform mixture) D. Intracellular: within a cell E. Extracellular: outside of a cell F. Intercellular: between cells (interstitial) II. Passive processes: no energy is expended by the cell A. Diffusion 1. Movement of molecules (e.g., water and ions) from a high concentration to a low concentration 2. Oxygen enters a cell and carbon dioxide exits a cell by simple diffusion through the lipid layer of the cell membrane B. Facilitated diffusion 1. Diffusion with the aid of carrier proteins 2. Glucose enters the cell by this method C. Osmosis 1. Movement of water through a semipermeable membrane from a region of low solute concen- tration (high solvent) to a region of high solute concentration (low solvent) 2. Water constantly moves in and out of the cell by osmosis 3. Osmotic pressure is the amount of pressure neces- sary to stop the flow of water across the membrane D. Filtration 1. Substances are forced through a membrane by hydrostatic pressure; small solutes will pass through; larger molecules will not 2. Important in kidney function III. Active processes: energy is expended by the cell A. Endocytosis: materials are taken into the cell 1. Phagocytosis (“cell eating”): cell membrane ex- tends around solid particles a. Some white blood cells and macrophages are phagocytic 2. Pinocytosis (bulk-phase) (“cell drinking”): cell membrane extends around fluid droplets a. Important in absorptive cells in small intestine 3. Receptor mediated: specialized membrane re- ceptors bind to substances entering the cell a. Enzymes, insulin, hormones, iron, and cho- lesterol enter the cell by this method B. Exocytosis: materials are expelled by a cell 1. Waste products are excreted and useful products are secreted into the extracellular space 2. Hormones, neurotransmitters, and mucus are released from the cell by this method C. Active transport 1. Movement of molecules from a low concentra- tion to a high concentration with the aid of carrier proteins VetBooks.ir
- 15. 4 PART l Anatomy and Veterinary Diagnostics 2. Sodium-potassium pump is an active transport pump within cell membranes; most ions and amino acids move into cells by this method IV. Hypotonic, hypertonic, and isotonic A. Hypotonic: extracellular fluid is less concentrated than the intracellular fluid 1. Red blood cells placed in a hypotonic solution will gain water through osmosis and burst (hemolysis) B. Hypertonic: extracellular fluid is more concentrated than the intracellular fluid 1. Red blood cells placed in a hypertonic solution will lose water through osmosis and crenate (shrivel) C. Isotonic: concentrations of the extracellular and in- tracellular fluids are equal 1. Red blood cells placed in an isotonic solution will remain unchanged, because osmotic pres- sures are equal TISSUES I. Tissue: groups of similar cells with related functions II. Histology or microanatomy: the study of tissues III. Four primary types of tissue A. Epithelial B. Connective C. Muscle D. Nervous Epithelial Tissue I. Covers body surface, lines body cavities, and forms the active part of glands A. Functions are protection, secretion, excretion, fil- tration, absorption of nutrients, and receipt of sen- sory information II. May form simple (one cell layer) or stratified (more than one cell layer) tissue III. Subtypes A. Squamous epithelium 1. Flat, thin, platelike cells 2. Simple squamous epithelial tissue lines blood vessels (endothelium), alveoli of lungs, and tho- racic and abdominal cavities 3. Stratified squamous epithelial tissue is found in areas of wear: nonkeratinized tissue lines the mouth, esophagus, vagina, and rectum; keratin- ized tissue makes up the epidermis B. Cuboidal epithelium 1. Cube-shaped cells 2. Simple cuboidal epithelial tissue is important in absorption and secretion; forms the active part of glands and small ducts, ovary surface, and kidney tubules 3. Stratified cuboidal epithelial tissue is fairly rare but lines the ducts of sweat, salivary, and mam- mary glands C. Columnar epithelium 1. Tall, rectangular cells a. Simple columnar epithelial tissue lines the di- gestive tract from stomach to rectum and is important for absorption and secretion; these cells also have a surface modification known as microvilli and are associated with mucus- secreting cells known as goblet cells b. Simple columnar epithelial tissue with cilia lines bronchi, uterine tubes, and uterus c. Stratified columnar epithelial tissue is rela- tively rare but is found in mammary ducts and portions of the male’s urethra D. Pseudostratified columnar epithelium 1. Appears to be more than one layer, but all cells touch the basal membrane 2. Usually ciliated and often associated with goblet cells (which secrete mucus); found in the respi- ratory tract E. Transitional epithelium 1. Mayresemblebothcuboidalandsquamousshapes depending on the thickness of the organ, but is found in areas where a great degree of distention is needed, such as the urinary bladder, ureters, and part of the urethra (cuboidal when bladder is empty and squamous when bladder is full) F. Glandular epithelium 1. Highly specialized epithelial cells with the ability to secrete various products 2. Classified as endocrine or exocrine a. Endocrine: ductless and secrete hormones directly into the bloodstream (e.g., estrogen secreted by ovaries) b. Exocrine: have ducts and secrete onto an epi- thelial surface (e.g., sweat glands) (1) Exocrine glands are numerous and classi- fied in many different ways, especially by their structure, method of secretion, and type of secretion Connective Tissue I. Widely distributed throughout the body and composed of threeelements:cells,fibers,andmatrix(groundsubstance) II. Has a variety of functions depending on tissue type (connects and supports, protects, insulates, transports fluids, and stores energy) III. Fiber types A. Collagen fibers (white fibers): long, straight, very strong white fibers composed of collagen B. Elastic fibers (yellow fibers): long, thin, branching, stretchable yellow fibers composed of elastin C. Reticular fibers: fine, collagen fibers in a complex network IV. Cell types A. Many different cell types depending on the tissue; immature and active cells have the suffix -blast, VetBooks.ir
- 16. Chapter 1 Animal Anatomy and Physiology 5 mature cells have the suffix -cyte, and cells that break substances down have the suffix -clast V. Connective tissue types are divided into two categories: connective tissue proper and specialized connective tis- sue and their subtypes (Table 1-1) Muscle Tissue I. Skeletal (striated) A. Voluntary control B. Long, parallel striated fibers with multiple nuclei located at their periphery C. Attach to and move bones II. Smooth A. Involuntary control B. Spindle-shaped, smooth cells with a centrally lo- cated nucleus C. Found in walls of hollow organs (e.g., digestive tract, blood vessels) D. Lack bony attachments III. Cardiac A. Involuntary control B. Long, striated cells that are joined at points known as intercalated discs; have a single, centrally located nucleus C. Found only in the heart (myocardium) Nervous Tissue I. Specialized for conducting electrical impulses II. Major locations are brain, spinal cord, and nerves III. Two major cell types: neurons, which conduct im- pulses, and neuroglial (glial) cells, which are support- ing cells and do not conduct impulses Type/subtype Examples and composition Connective Tissue Proper Loose Areolar Most widely distributed; supports organs; protects and provides flexibility for all three fiber types Fibroblasts, macrophages, mast cells, white blood cells Adipose Insulates, protects, cushions Reserve energy composed of fat cells (adipocytes) Reticular Supportive tissue Found in spleen, liver, lymph nodes, and bone marrow Network of fine reticular fibers, macrophages, and fibroblasts Dense Regular Tendons (bone to muscle), ligaments (bone to bone), and aponeuroses (muscle to muscle) Collagen fibers arranged in a parallel pattern and fibroblasts provide strong attachments Irregular Dermis of the skin, organ capsules, joint capsules Collagen fibers arranged in an irregular pattern, elastic fibers, fibroblasts Provide strength and support to areas experiencing tension from all directions Elastic Ligaments that contain more elastic fibers than collagen; nuchal ligament in horse’s neck Specialized Cartilage Hyaline Nose, trachea, larynx, embryonic skeleton, costal cartilage, articular cartilage Collagen fibers and chondrocytes support with some flexibility Elastic Pinna, auditory canal, epiglottis, elastic fibers Provides shape and great flexibility Fibrocartilage Intervertebral discs, pubic symphysis, disc in stifle thick collagen fibers, and chondrocytes Provide strong support Bone (osseous) Compact (dense) Bones, collagen fibers, osteocytes, and calcified matrix Supports, protects, houses blood-producing tissue; stores calcium and other minerals Blood Spongy (cancellous) Lattice-like bone structure Erythrocytes, leukocytes, thrombocytes, plasma TABLE 1-1 Connective Tissue Categories VetBooks.ir
- 17. 6 PART l Anatomy and Veterinary Diagnostics MEMBRANES I. Membranes are made up of more than one tissue, which is usually a type of epithelial tissue attached to a type of connective tissue II. There are three types of membranes A. Mucous membranes (mucosae) 1. Membranes that line hollow organs and con- nect to the exterior 2. Usually stratified, squamous, or simple colum- nar epithelium attached to loose connective tis- sue known as lamina propria 3. Mucous membranes are adapted to absorb and secrete; normally secrete mucus, which lubricates both the respiratory and digestive pathways 4. The color of mucous membranes is used to evaluate many conditions in animals (e.g., blue mucous membranes indicate hypoxia) B. Serous membranes (serosa) 1. Membranes that line body cavities but do not connect to the exterior 2. Simple squamous epithelium connected to a layer of loose connective (areolar) tissue 3. Secretes a thin, watery fluid (i.e., serous fluid), which reduces friction between parietal and visceral surfaces 4. Serous membranes are named according to their location and organ (e.g., parietal perito- neum and visceral peritoneum, parietal peri- cardium and visceral pericardium, parietal pleura and visceral pleura) C. Cutaneous membranes (integument or skin) 1. Consist of keratinized, stratified squamous epithelium (epidermis) attached to a layer of dense irregular connective tissue (dermis) 2. Because it is exposed to the environment,it pro- vides durability, protection, and waterproofing DIRECTIONAL TERMINOLOGY I. Cranial: toward the head (e.g., the thoracic vertebrae are cranial to the sacral vertebrae) II. Rostral: toward the nose; used to describe struc- tures on the head (e.g., the maxilla is rostral to the occipital) III. Caudal: toward the tail (e.g., the lumbar vertebrae are caudal to the cervical vertebrae) IV. Dorsal: toward the backbone (e.g., the thoracic verte- brae are dorsal to the sternum) V. Ventral: away from the backbone (e.g., the umbilicus is on the ventral surface of the cat) VI. Medial: closest to the median plane (e.g., the tibia is medial to the fibula) VII. Lateral: farthest from the medial plane (e.g., the ribs are lateral to the sternum) VIII. Proximal:the point closest to the backbone;used espe- cially in reference to limbs (e.g., the greater trochanter is on the proximal end of the femur) IX. Distal: the point farthest from the backbone; used especially in reference to limbs (e.g., the fabella is located at the distal end of the femur) X. Anterior: toward the head; used especially in refer- ence to limbs (e.g., the patella is on the anterior as- pect of the rear leg) XI. Posterior: toward the tail; used especially in refer- ence to limbs (e.g., the Achilles tendon is on the posterior aspect of the rear leg) XII. Palmar: bottom of the front foot XIII. Plantar: bottom of the rear foot XIV. Superficial: toward the outer surface of the animal (e.g., skin is superficial to the muscle) XV. Deep: away from the outer surface of the animal (e.g., bone is deep to the muscle) BODY SYSTEMS Skeletal System I. Osteology: study of bones II. Skeletal divisions A. Axial skeleton 1. Bones found on the midline or attached to it (excludes the limbs) 2. Examples include the ribs, skull, vertebral col- umn, and sternum B. Appendicular skeleton 1. Allbonespresentinthelimbs(e.g.,femur,humerus) III. Function of bones A. Support soft tissues of the body B. Protect vital organs (e.g., heart) C. Act as levers for muscle attachment D. Store minerals E. Produce blood cells IV. Types of bone A. Compact (dense) bone 1. Has very few spaces, appears solid, and pro- vides strength and support 2. Made of haversian systems (osteons); each sys- tem is composed of the following: a. Central haversian canal: houses blood ves- sels and nerves b. Canaliculi: very small canals that radiate out, connecting all lacunae to each other and to the central haversian canal c. Lamellae: concentric rings of bone d. Lacunae: small spaces that house osteocytes (mature bone cells) B. Spongy (cancellous) bone 1. No haversian systems 2. Has large spaces between lattice-like pieces of bone known as trabeculae VetBooks.ir
- 18. Chapter 1 Animal Anatomy and Physiology 7 3. Spaces are filled with marrow 4. Spongy bone of the skull is known as diploë V. Types of bone cells A. Osteoblast: immature bone cell that produces the bone matrix known as osteoid B. Osteocyte: mature bone cell; each cell occupies a lacunae in bone C. Osteoclast: very large multinucleated cells that are capable of dissolving bone matrix and releasing minerals, which is a process known as osteolysis, or resorption 1. It is important for the body to maintain a balance between osteoblast and osteoclast activity VI. Classification of bones A. Long bones 1. Consist of a long cylindrical shaft (diaphysis), two ends (epiphyses), and a marrow cavity (e.g., radius, femur) 2. Main supporting bones of the body 3. Parts of a long bone (Figure 1-1) a. Diaphysis: shaft b. Epiphysis: proximal or distal end of the bone c. Articular cartilage: hyaline cartilage that covers the ends of the bones d. Periosteum: fibrous membrane covering outside of bone; rich in blood, nerves, and lymphatic vessels e. Endosteum: lines the marrow cavity f. Medullary (marrow) cavity: space within the bone center that contains marrow (red or yellow); red marrow is hematopoietic tissue that produces blood cells; yellow marrow is primarily fat g. Epiphyseal cartilage: region between diaphy- sis and epiphysis where bone grows in length; often referred to as the growth plate; becomes the epiphyseal line in mature animals B. Short bones 1. Small, cube-shaped bones 2. Two thin layers of compact bone with spongy bone between the layers 3. Function as shock absorbers (e.g., carpus, tarsus) C. Flat bones 1. Thin, flat bones 2. Two layers of compact bone with spongy bone between the layers; resembles a sandwich 3. Have a protective function (e.g., pelvis, scapula, ribs, and many bones of the skull) D. Pneumatic bones 1. Contain sinuses (e.g., frontal) E. Irregular bones 1. Unpaired bones with complicated shapes that do not fit any other category (e.g., vertebra, some skull bones) F. Sesamoid bones 1. Found near freely moving joints 2. Small short bones attached to tendons 3. Reduce friction along a joint (e.g., patella) VII. Osteogenesis (ossification): formation of bone A. Endochondral 1. Bones formed from cartilage bars laid down in the embryo 2. Majority of bones in the body are formed by this method B. Intramembranous 1. Bones formed from fibrous membranes laid down in the embryo 2. Most flat bones are formed by this method 3. Osteoblasts produce new bone and become mature osteocytes VIII. Skeletal species differences (see Table 1-2 and Figure 1-2 for species variations of vertebral formulas) A. Cat has a clavicle; dog does not B. Male dogs and cats have a nonarticulating bone (baculum or os penis) in the penis C. Cattle have a nonarticulating bone (os cordis) in the heart Articular cartilage Spongy bone Epiphyseal plate Epiphyseal plate Red marrow cavities Compact bone Medullary cavity Endosteum Yellow marrow Periosteum Diaphysis Epiphysis Epiphysis FIGURE 1-1 Parts of a long bone. VetBooks.ir
- 19. 8 PART l Anatomy and Veterinary Diagnostics IX. Articulations (joints) A. Formed when two or more bones are united by fi- brous, elastic, or cartilaginous tissue B. Classification by function 1. Synarthrosis:immovablejoint(e.g.,skullsutures) 2. Amphiarthrosis: slightly movable joint (e.g., pubic symphysis) 3. Diarthrosis: freely movable joint (e.g., stifle) C. Classification by structure 1. Fibrous: united by fibrous tissue; no joint cav- ity; synarthroses (e.g., skull sutures) 2. Cartilaginous: united by cartilage; no joint cav- ity; amphiarthroses (e.g., intervertebral discs, pubic symphysis) 3. Synovial: joint cavity filled with synovial fluid; synovial membrane and joint capsule; diar- throses (e.g., all joints of the limbs) a. Majority of the joints in the body are synovial b. They are classified into several types based on structure and function (Table 1-3) Muscular System I. Function A. Produces movement of entire body or parts B. Maintains posture C. Produces heat Species No. cervical vertebrae No. thoracic vertebrae No. lumbar vertebrae No. sacral vertebrae No. caudal or coccygeal vertebrae Dog, cat 7 13 7 3 6-23 Horse 7 18 6 5 15-20 Cattle 7 13 6 5 18-20 Pig 7 14-15 6-7 4 20-23 Sheep 7 13 6-7 4 16-18 Human 7 12 5 5 4 TABLE 1-2 Vertebral Formulas C1, atlas C2, axis Ligamentum nuchae Scapula C7, last cervical vertebra Cranial end of sternum (manubrium) Humerus Olecranon (point of elbow) Ulna Radius Carpal bones Metacarpal bones Proximal, middle, and distal phalanges Sacrum Cy1, first vertebra (coccygeal) Os coxae (pelvis) Femur Patella Fibula Tibia L1, first lumbar vertebra T1, first thoracic vertebra Tarsal bones Calcaneus (point of hock) Metatarsal bones Caudal end (xiphoid) of sternum FIGURE 1-2 Canine skeleton. (From Colville T, Bassert JM: Clinical anatomy and physiology for veterinary technicians, ed 2, St Louis, Mosby, 2008.) VetBooks.ir
- 20. Chapter 1 Animal Anatomy and Physiology 9 II. Types There are three types of muscle: skeletal, smooth, and cardiac A. Skeletal muscle (striated, voluntary) 1. Skeletal muscle cells are long, striated fibers that run parallel to each other 2. Cells are multinucleated with the nuclei on the periphery 3. Each muscle fiber is a muscle cell consisting of many myofibrils 4. Myofibrils are composed of myofilaments (i.e., actin and myosin) 5. Functional unit is a sarcomere a. Z line: connective tissue that lies between the sarcomeres b. M line: runs through the exact center of the sarcomere c. A band: darker striations, total length of thick filament, includes portions of the thin liga- ment (actin) d. H zone: area within the A band with only thick filaments (myosin only) e. I Band: lighter striations, area of the sarco- mere with only thin filament (actin only) B. Smooth muscle (visceral, nonstriated, involuntary) 1. Smooth muscle cells are spindle shaped with one centrally located nucleus and no striations 2. Responsible for involuntary movement (e.g., digestion) 3. Two types of smooth muscle: single unit or visceral smooth muscle, and multiunit smooth muscle 4. Single-unit smooth muscle is found in sheets and forms the walls of many hollow organs (e.g., intestines); contraction occurs in waves 5. Multiunit smooth muscle is found as individual fibers, and the fibers are activated by the auto- nomic nervous system (e.g., arrector muscle of hair, eye muscles) C. Cardiac muscle (myocardium) 1. Involuntary, striated cells that branch to form a network 2. Cells are joined by intercalated discs, which aid in conduction of the nervous impulse to coordi- nate contraction D. Contraction of skeletal muscle by mechanism de- scribed in the sliding-filament theory 1. A nerve impulse travels down a motor nerve axon 2. Acetylcholine is released into the synaptic cleft, transmitting the impulse to the sarcolemma 3. Impulse is conducted into the T tubules and to the sarcoplasmic reticulum 4. Calcium is released from the sarcoplasmic reticulum 5. Calcium binds to troponin, which causes a change in the conformation of tropomyosin 6. This change exposes the myosin binding sites on the actin 7. ATP is hydrolyzed, providing the energy re- quired for contraction 8. Myosin binds to actin, forming cross-bridges 9. Myosin shortens,brings Z bands closer together a. Cross-bridges detach, move, and reattach b. Myosin continues to attach, pull, and detach, which moves the actin toward the center of the sarcomere during this active phase of muscle contraction 10. When the nerve impulse stops, calcium is ac- tively transported back into the sarcoplasmic reticulum and muscle relaxes; energy is also re- quired for relaxation 11. All-or-none principle states that muscle fibers either contract to their fullest or not at all Synovial joint Structure Location Movement Ball and socket (spheroid) Ball-shaped head articulates with cup-shaped depression Shoulder, hip Flexion, extension, abduction, adduction, rotation, circumduction Arthrodial (condyloid) Oval articulating surfaces Radiocarpal joints Flexion, extension Trochoid (pivot) Rounded end of one bone articulates with a ring of bone Atlantoaxial Rotation Hinge (ginglymus) Cylindrical bone fits into depression Stifle, elbow Flexion, extension Gliding Flat, articulating surfaces Radioulnar, intervertebral Flexion, extension Saddle Concave surface articulates with a convex bone Carpometacarpal, in primates only Flexion, extension, abduction, adduction, rotation, circumduction TABLE 1-3 Types of Synovial Joints VetBooks.ir
- 21. 10 PART l Anatomy and Veterinary Diagnostics E. Skeletal muscle actions 1. Flexor: usually decreases the angle of a joint 2. Extensor: usually increases the angle of a joint 3. Abductor: moves a bone away from the midline 4. Adductor: moves a bone toward the midline 5. Levator: produces a dorsally directed movement 6. Depressor:producesaventrallydirectedmovement 7. Sphincter: decreases the size of an opening Nervous System The central nervous system (CNS) consists of the brain and spinal cord (Figure 1-3). I. Brain A. Cerebrum 1. Site of motor control, interpretation of sensory impulses, and areas of association 2. Basic arrangement consists of outer gray matter, which contains neuron cell bodies, and inner white matter, which consists mainly of axons 3. Surface area increased by gyri (elevations) and sulci (fissures) 4. Longitudinal fissure: Prominent groove that divides the cerebrum into right and left hemispheres 5. Divided into four lobes, the frontal lobe, pari- etal lobe, occipital lobe, and temporal lobe B. Diencephalon 1. Region of thalamus and hypothalamus 2. Thalamus acts as a relay station for sensory im- pulses and interprets some sensations, such as temperature and pain 3. Hypothalamus regulates many homeostatic functions (e.g., body temperature, fluid bal- ance, thirst, urine output, food intake, emotion, and behavioral patterns) and has an important connection with the endocrine system C. Brain stem 1. Consists of midbrain, pons, and medulla oblongata 2. Midbrain serves as a connecting link between forebrain (cerebrum) and the hindbrain 3. Pons contains important respiratory centers 4. In the medulla oblongata, nerve fibers cross from left to right, and vice versa 5. Medulla also influences respiratory rate, heart rate, vomiting, coughing, and sneezing 6. Throughout the brain stem is the reticular ac- tivating system (RAS), which is responsible for sleep/wake cycles D. Cerebellum 1. Responsible for coordination and balance II. Spinal cord A. Runs through the vertebral foramen B. Basic arrangement consists of outer white mat- ter, which contains nerve fibers, and a butterfly- shaped inner region of gray matter composed of neuron cell bodies C. Contains ascending and descending nerve tracts D. Major function is to convey sensory (afferent) nerve impulses from the periphery to the brain and to conduct motor (efferent) nerve impulses from the brain to the periphery E. Brain and spinal cord are protected by bone and meninges III. Meninges A. Dura mater: outer layer composed of dense, fibrous connective tissue B. Arachnoid (arachnoidea) mater: middle layer con- sisting of very delicate and elastic connective tissue C. Pia mater: transparent, delicate connective tissue that contains tiny blood vessels and adheres to the surface of the brain and spinal cord D. Epidural space: between bone and dura mater; contains loose connective tissue, blood vessels, and fat; injection of anesthetic agents into this re- gion causes temporary nerve paralysis E. Subarachnoid space: contains cerebrospinal fluid and large blood vessels FIGURE 1-3 Anatomy of the central nervous system. (From Colville T, Bassert JM: Clinical anatomy and physiology for veterinary techni- cians, ed 2, St Louis, Mosby, 2008.) Thalamus Hypothalamus Midbrain Pons Medulla Cerebrum Brain Cerebellum Cervical Thoracic Lumbar Sacral Spinal nerves Spinal cord Diencephalon Brain stem VetBooks.ir
- 22. Chapter 1 Animal Anatomy and Physiology 11 IV. Cerebrospinal fluid (CSF) A. Colorless, watery fluid; contains protein, glucose, ions, and other substances B. pH and pressure are particularly important C. Cushions and nourishes the brain D. A lumbar or CSF tap is used for CSF sampling V. Blood-brain barrier A. The blood-brain barrier protects the brain from fluctuations in chemical levels that are present within the bloodstream B. Endothelial cells of the capillaries in the brain are joined by tight junctions, thereby forming an im- permeable barrier (i.e., the blood-brain barrier) C. Lipid-soluble substances, such as oxygen, carbon dioxide, and steroid hormones, enter the brain by dissolving through the capillary cell walls D. Essential substances (e.g., glucose and amino ac- ids) are transported into the brain by facilitated diffusion E. Many other substances (e.g., waste products and drugs) are blocked by the blood-brain barrier VI. Peripheral nervous system (PNS) A. Consists of all nerve processes connecting to the CNS; includes all cranial and spinal nerves B. Divided into two major divisions: afferent (sen- sory) and efferent (motor) C. Afferent or sensory nerves carry impulses from sensory receptors to the CNS for interpretation D. Efferent or motor nerves carry impulses from the CNS to skeletal muscle as part of the somatic divi- sion and to smooth muscle, glands, and heart as part of the autonomic system E. All voluntary movements are part of the somatic division F. The autonomic division serves all the involuntary functions and is further divided into sympathetic and parasympathetic nervous systems 1. Sympathetic nerve fibers elicit the fight-or- flight response in emergencies or stressful situ- ations (e.g., increased heart rate, respiratory rate, and blood flow) 2. Parasympathetic nerve fibers are responsible for quiet activities (e.g., digestion, heart rate) and return the body to normal levels after the sympathetic response 3. The sympathetic and parasympathetic nervous systems work together to maintain homeostasis VII. Principal cells of the nervous system A. Neuron (nerve cell) 1. Composed of dendrites, cell body, and axon 2. Dendrites receive the impulse and conduct it to the cell body, which in turn conducts it to the axon, which leads the impulse away to a synapse 3. Nerve impulses are generated by action potentials 4. An action potential is depolarization followed by repolarization; the electrical charge of the cell is reversed and then returned to normal 5. Neurons operate on an all-or-nothing principle, they depolarize completely or not at all 6. Impulses travel in one direction 7. Nerve cell bodies cannot regenerate if damaged 8. Some nerve cells have an insulative covering known as myelin; myelin is interrupted at the nodes of Ranvier—impulses jump from node to node, making transmission along myelin- ated nerve fibers faster than along nonmyelin- ated nerve fibers. This mode of conduction is known as saltatory conduction B. Neuroglial cells (glial) 1. Connective tissue cells within the CNS and PNS; are supportive and protective only and do not transmit impulses 2. There are six types: four are found in the CNS and two in the PNS 3. Glial cells in the CNS a. Astrocytes: star shaped, most abundant, support nervous tissue, stimulate formation of blood-brain barrier b. Oligodendrocyte: smaller, wrap around ax- ons to form myelin in CNS c. Microglia: phagocytic cells d. Ependymal: ciliated,which helps circulate CSF 4. Glial cells in the PNS a. Schwann cells: wrap around axons to form myelin in peripheral nerves; comparable to oligodendrocytes in the CNS b. Satellite cells: surround cell bodies but func- tion is unknown VIII. Reflexes A. Automatic response to a stimulus 1. Reflex arc involves a stimulus that is picked up by sensory receptors 2. The impulse is transmitted along a sensory neuron to the spinal cord, where it synapses with an interneuron (three-head neuron reflex) or directly with a motor neuron (two-head neuron reflex) 3. Impulse hits the effector organ, causing a response 4. Some typical reflexes are the stretch reflex (knee-jerk reflex), withdrawal reflex, corneal reflex, and papillary light reflex Cardiovascular System The cardiovascular system includes the heart (cardio) and blood vessels (vascular). I. Function A. Heart provides the force to circulate blood to all parts of the body VetBooks.ir
- 23. 12 PART l Anatomy and Veterinary Diagnostics II. Structure (Figure 1-4) A. Myocardium is the heart (cardiac) muscle B. Cardiac muscle cells are striated and are connected by intercalated discs C. Intercalated discs have a low electrical resistance; therefore the impulse spreads very quickly and cells contract and relax as a unit III. Protective layers A. Pericardium: a double-walled membranous sac covering the myocardium 1. The outer layer, enveloping the heart, is a tough fibrous connective tissue known as fibrous pericardium; deep to this layer is a more deli- cate layer known as serous pericardium 2. Serous pericardium has two layers: the parietal layer adheres to the fibrous pericardium, and the visceral layer adheres to the myocardium 3. Space between the two layers of serous pericar- dium is the pericardial cavity, filled with peri- cardial fluid, which reduces friction when the heart beats B. Endocardium: a serous membrane lining the inner chambers of the heart IV. Pulmonary circulation A. Consists of the precava (cranial vena cava or supe- rior vena cava) and postcava (caudal vena cava or inferior vena cava) B. Precava and postcava empty into the right atrium; blood then passes through the tricuspid valve into the right ventricle and through the pulmonary artery (passes pulmonary semilunar valve) to the lungs, where the blood is oxygenated and returned to the heart via pulmonary veins V. Systemic circulation (somatic circulation) A. Oxygenated blood enters the left atrium via the pul- monaryveinsandflowsthroughthebicuspid(mitral) valve to the left ventricle and out of the aorta (passes aortic semilunar valve) to all parts of the body B. Two branches come off of the aortic arch in dogs and cats 1. Innominate artery (brachiocephalic), which branches into the right subclavian artery and right and left common carotid arteries 2. Left subclavian artery VI. Coronary circulation A. Coronary arteries provide nutrients and oxygen to the myocardium; myocardial perfusion occurs during heart relaxation B. Coronary veins drain waste and carbon dioxide from the myocardium VII. Cardiac cycle A. One complete cycle: as atria contract (systole), the ventricles relax (diastole); and as ventricles con- tract, the atria relax B. Atrial diastole: atria are at rest 1. Right atrium is receiving blood from the pre- cava and postcava while the left atrium is re- ceiving blood from the pulmonary veins FIGURE 1-4 Anatomy of the heart. (From Colville T, Bassert JM: Clinical anatomy and physiology for veterinary technicians, ed 2, St Louis, Mosby, 2008.) Cranial vena cava (from head and arms) To upper right lobe To lower right lobe To middle right lobe Branches of right pulmonary artery Branches of left pulmonary artery Branches of right pulmonary vein Branches of left pulmonary vein From lung From lung Semilunar valve Right atrium Triscuspid valve Caudal vena cava (from trunk and legs) Right ventricle Arch of aorta To lung Pulmonary artery Left atrium Aortic semilunar valve Mitral valve Left ventricle Septum Myocardium (heart muscle) Descending aorta VetBooks.ir
- 24. Chapter 1 Animal Anatomy and Physiology 13 C. Atrial systole: atria are contracting 1. Sinoatrial (SA) node fires, causing contraction of the atria; blood is pushed through the tricuspid andbicuspidvalvesintotherightandleftventricles D. Ventricular diastole 1. Ventricles receive blood from the atria E. Ventricular systole 1. Impulse from the SA node has been conducted to the atrioventricular (AV) node, which con- ducts the impulse down the bundle of His (AV bundle) to the Purkinje fibers 2. Ventricles are now stimulated to contract; blood is forced through the semilunar valves into the pulmonary artery to the lungs, and out of the aorta to all parts of the body VIII. Heart sounds A. Auscultation (listening to heart sounds) 1. Lubb, dupp, pause a. Lubb is the first sound; it is a long sound made when the AV valves close b. Dupp is the second sound; it is a short, sharp sound made when the semilunar valves close IX. Heart rate A. Animal heart rates vary with age, size, breed, health, and fitness; heart rate is also affected by chemicals, hormones,temperature,behavior,andrespiratoryrate B. Dog: 70 to 160 beats per minute C. Cat: 150 to 210 beats per minute D. Horse: 28 to 50 beats per minute E. Cattle: 40 to 80 beats per minute X. Electrocardiography (ECG [or EKG]) A. Electrocardiogram records the electrical activity of the heart B. First wave is the P wave, which represents the elec- trical events during atrial systole (depolarization) C. Large QRS complex represents the electrical events of ventricular systole (depolarization) D. T wave represents the electrical events during ven- tricular diastole (repolarization) E. Atrial diastole occurs during ventricular systole; therefore it is masked by the QRS complex Central Vascular System I. Blood vessels A. Arteries 1. Carry blood away from the heart 2. Carry oxygenated blood (except for pulmonary artery) 3. Are thicker and stronger than veins 4. Pressure within is greater than in veins B. Arterioles 1. Small arteries 2. Lead to capillaries and regulate the blood flow into them C. Capillaries 1. Consist of one layer of endothelium 2. Microscopic diameter 3. Exchange of oxygen and carbon dioxide takes place here D. Venules 1. Emerge from capillaries and enlarge into veins E. Veins 1. Are larger than arteries and have thinner walls 2. Venous blood pressure is low; therefore they have valves to prevent the backflow of blood 3. Carry blood back to the heart II. Blood pressure A. The force exerted by the circulating blood on the vessel walls B. Systolic: Force exerted during contraction of the ventricles (maximum) C. Diastolic: Force exerted while the ventricles are re- laxed (minimum) III. Fetal circulation A. Lungs, kidneys, and digestive tract are nonfunc- tional in fetus but must be nourished with oxygen B. Exchange of nutrients and waste takes place within the placenta C. Oxygenated blood enters the fetus via one umbilical vein D. Vein ascends toward the fetal liver and divides into two; one branch joins the hepatic portal vein and enters the liver, and the majority of blood flows into the ductus venosus, which connects to the postcava E. Postcava enters the right atrium; precava from the head also enters the right atrium F. Most of the blood goes directly through the fora- men ovale to the left atrium, into the left ventricle, and out of the aorta to all parts of the fetus G. Blood that goes into the right ventricle passes into the pulmonary artery; most blood is diverted through the ductus arteriosus into the aorta (a small amount goes to the lungs) H. Blood in the descending aorta branches into the iliac arteries; the two umbilical arteries branch off and return deoxygenated blood to the placenta I. Both the foramen ovale and ductus arteriosus close shortly before birth Digestive System The digestive system breaks down foodstuff into absorb- able nutrients to fuel the body. There are anatomical varia- tions among different species depending on their diet. I. Process A. Digestive system uses five basic processes to prepare the food for utilization by the body 1. Ingestion of food 2. Mechanical and chemical digestion 3. Peristalsis: moving food through the digestive tract via smooth muscle contractions 4. Absorption 5. Defecation VetBooks.ir
- 25. 14 PART l Anatomy and Veterinary Diagnostics II. Types of diets A. Herbivore: plant-eating animal (e.g., rabbit, cattle, horse, sheep) B. Carnivore: meat-eating animal (e.g., cat, dog, tiger) C. Omnivore: plant- and meat-eating animal (e.g., rats, pigs, humans) III. Histological layers A. Walls of gastrointestinal tract or alimentary canal can be divided into four layers 1. Mucosa, closest to the lumen: three sublayers a. Epithelium: stratified squamous and simple columnar b. Lamina propria: connective tissue c. Muscularis mucosae: smooth muscle 2. Submucosa: loose connective tissue 3. Muscularis externa: two or three layers of smooth muscle depending on location a. Oblique muscle: stomach has all three layers b. Circular muscle c. Longitudinal muscle 4. Serosa: loose connective tissue IV. Structures A. Mouth 1. Receives food and mixes it with saliva during mastication 2. Bolus is formed B. Pharynx 1. Common passageway for digestive and respira- tory systems C. Esophagus 1. Muscular tube running from the pharynx to the cardia (opening to stomach) 2. Food moves through the esophagus via peristalsis D. Stomach 1. Simple stomach: monogastric animals a. Found in humans, pigs, horses, and dogs b. Fourregions:esophageal,cardiac,fundic,pyloric (1) Esophageal region is nonglandular (2) Cardiac region produces mucus (3) Fundic region is the true body of the stomach and contains true gastric glands, which have four distinct cell types (a) Mucous neck cells, which secrete mucus (b) Chief cells, which produce the en- zyme pepsinogen (c) Parietal cells, which produce hydro- chloric acid (d) Endocrine cells, which produce the hormone gastrin (4) Pyloric region produces mucus c. Has inner folds known as rugae d. Food is mixed in the stomach with secretions from the digestive glands until it is reduced to a liquid known as chyme e. pH of stomach is acidic 2. Ruminant stomach a. Found in cattle, sheep, goats, and llamas b. All ruminants are herbivores, but not all her- bivores are ruminants c. Animal regurgitates food (bolus), remasticates (rechews), and swallows it again (deglutition) d. Composed of four compartments: rumen, re- ticulum, omasum, and abomasum (1) Rumen: called “fermentation vat” (a) Largest compartment (b) Food is mixed and churned in a fa- vorable environment (i.e., proper pH, temperature, bacteria, and an- aerobic conditions) (2) Reticulum: called“hardware compartment” (a) Most cranial compartment that is not completely separate from the rumen (b) Also called the “honeycomb” (c) Acts as a passageway for food, paces the contraction of the rumen, and is the usual site for ingested foreign objects (3) Omasum (a) Grinds up the food and absorbs wa- ter and bicarbonate (b) Composed of many layers of lami- nae, which resemble leaves (4) Abomasum (a) True glandular stomach (b) Mixes the food with enzymes, initi- ating chemical digestion E. Small intestine 1. Divided into three regions: duodenum, jejunum, ileum 2. Major site of digestion and absorption 3. Three specialized structures increase the surface area of the small intestine a. Circular folds: deep, mucosal folds b. Intestinal villi: long, slender projections c. Microvilli: columnar epithelial cells have microvilli 4. Produces digestive enzymes (proteases, amylases, and lipase) F. Large intestine 1. Cecum found at the ileocecocolic junction 2. Colon (ascending, transverse, descending) 3. Has no villi, circular folds, or secreted enzymes; large number of goblet cells secrete mucus 4. Absorbs water, produces vitamins B and K, and propels waste toward the rectum G. Rectum 1. End portion of the large intestine that secretes mucus H. Anus 1. Terminal ending of gastrointestinal tract VetBooks.ir
- 26. Chapter 1 Animal Anatomy and Physiology 15 2. Has two sphincters: one internal involun- tary sphincter and one external voluntary sphincter I. Other organs that are involved 1. Pancreas: releases sodium bicarbonate, which neutralizes acidic chyme and digestive enzymes into the duodenum a. Trypsin: to digest proteins b. Lipase: to digest fat c. Amylase: to digest starch 2. Liver: produces bile, which emulsifies fats 3. Gallbladder: stores bile and releases it into the duodenum when fats are present a. Under the influence of cholecystokinin (CCK) b. Rats and horses do not have a gallbladder V. Digestive process (simple stomach) A. Food enters the mouth and is mixed with salivary amylase (from salivary glands: parotid, sublingual, mandibular, and zygomatic) B. Amylase begins to break down starch C. Food entering the stomach is mixed with gastric juice composed of protein-digesting enzymes, hy- drochloric acid, and mucus D. Rennin (chymosin) is also present in the young to coagulate milk E. In the small intestine, the chyme is acted on by pan- creatic enzymes 1. Pancreatic amylase: to act on starch 2. Trypsin: to act on proteins 3. Chymotrypsin: to act on proteins 4. Elastase: to act on elastin 5. Peptidases: to act on large peptides (proteins) 6. Lipase: to act on fats 7. Nucleases: to act on nucleic acids F. Pancreatic enzymes are delivered in an alkaline fluid to help neutralize the acidic chyme G. Small intestine also secretes enzymes 1. Trypsin: to act on dipeptides 2. Maltase,sucrase,andlactase:toactondisaccharides 3. Nuclease: to act on nucleic acids 4. Chyme is mixed with enzymes through segmen- tation and moves via peristalsis 5. Monosaccharides and amino acids are absorbed through the intestinal capillaries, and fats are ab- sorbed through the lacteals of the intestinal villi H. Large intestine absorbs water, produces vitamins B and K, and moves solid waste to the rectum for defecation I. Defecation of undigested waste occurs through the anus Lymphatic System I. Function A. Absorbs protein-containing fluid that escapes from capillaries in tissues and returns it to the venous system B. Transports fats from digestive tract to blood C. Produces lymphocytes D. Develops immunity II. Structure A. Lymph vessels 1. Blind-ended tubes, running parallel to venous system, that eventually empty into precava 2. Resemble veins but have thinner walls and more valves; lymph is filtered through the lymph nodes B. Lymph nodes (glands) 1. Oval-shaped structures 2. Filter lymph 3. Produce lymphocytes C. Lymph organs 1. Spleen a. Largest mass of lymphoid tissue b. Phagocytic function c. Produces lymphocytes d. Stores and releases blood as needed 2. Tonsils a. Mass of lymphoid tissue embedded in mu- cous membrane b. Supplied with reticuloendothelial cells 3. Thymus a. Located in the cranial chest cavity, between the trachea and the ribs b. Important in developing immune response in the young c. Eventually replaced by fat in the adult, de- pending on the species Respiratory System I. Structures A. Nostrils (nares) 1. External openings B. Nasal cavity 1. Lined with mucous membrane 2. Houses turbinate bones 3. Air is warmed by capillaries, moistened, and filtered C. Pharynx 1. Nasopharynx: from posterior nares to soft palate 2. Oropharynx: from soft palate to hyoid bone 3. Laryngopharynx: from hyoid bone to larynx 4. Eustachiantube:frommiddleeartonasopharynx D. Larynx (voice box) 1. Consists of cartilage (e.g., thyroid, cricoid, aryte- noid, and epiglottis) 2. Epiglottis covers the glottis during swallowing 3. Vocal folds attach to arytenoid cartilage E. Trachea 1. Consists of noncollapsible, C-shaped, cartilagi- nous rings 2. Lined with ciliated columnar cells 3. Divides into bronchi at the tracheal bifurcation VetBooks.ir
- 27. 16 PART l Anatomy and Veterinary Diagnostics F. Bronchi 1. Right and left cartilaginous bronchi enter the lungs 2. Passageways become progressively smaller, and the amount of cartilage diminishes G. Bronchiole 1. Consists of smooth muscle, no cartilage 2. Lead to the alveoli H. Lungs 1. Varying number of lobes, depending on species 2. Covered with visceral pleura 3. House microscopic air sacs known as alveoli, where exchange of oxygen and carbon dioxide takes place II. Physiology A. Respiration of mammals: three basic processes 1. Ventilation: movement of air between the atmo- sphere and the lungs 2. External respiration: exchange of gases between the alveoli and the blood 3. Internal respiration: exchange of gases between the blood and the cells B. Ventilation 1. Inspiration (inhalation) a. Nervous impulse from the brain causes the diaphragm and external intercostal muscles to contract b. Diaphragm moves caudally and the chest moves ventrally; therefore the size of the thoracic cavity is increased, which decreases intrathoracic pressure and intraalveolar pressure c. Because intraalveolar pressure is now less than atmospheric pressure, air moves into the lungs 2. Expiration (exhalation) a. Diaphragm and external intercostal muscles relax b. Diaphragm moves cranially and the chest moves dorsally; this decreases the size of the thoracic cavity, which increases intrathoracic pressure and intraalveolar pressure c. Because intraalveolar pressure is now greater than atmospheric pressure, air moves out of the lungs d. Expiration is a passive process III. Lung volumes A. Tidal volume: the volume of air exchanged during normal breathing B. Inspiratory reserve volume: the amount of air in- spired over the tidal volume C. Expiratory reserve volume: the amount of air ex- pired over the tidal volume D. Residual volume: air remaining in the lungs after a forced expiration E. Dead space: air in the pathways of the respiratory system IV. Respiratory rate A. Dog: 10 to 30 breaths per minute B. Cat: 24 to 42 breaths per minute C. Horse: 8 to 16 breaths per minute D. Cattle: 12 to 36 breaths per minute V. Control of respiration A. Medullary rhythmicity center in the medulla ob- longata, a region that has inspiratory and expiratory neurons B. Apneustic area in the pons, which prolongs inspiration C. Pneumotaxic area in the pons, which inhibits the apneustic area and causes expiration D. Hering-Breuer reflex: stretch receptors in the lungs that prevent the lungs from overinflating E. Carbon dioxide: an increase in carbon dioxide causes an increase in respiratory rate F. Other factors may affect the rate of respiration (e.g., pain, cold, blood pressure, pH, oxygen, stress) VI. Terminology A. Pneumothorax: air in the thoracic cavity B. Atelectasis: collapsed lungs C. Pleuritis (pleurisy): inflammation of the pleural membranes D. Pneumonia: inflammation of the lungs caused pri- marily by bacteria, viruses, or chemical irritants E. Eupnea: normal, quiet respiration F. Dyspnea: difficult breathing G. Apnea: no breathing Excretory System I. Anatomy A. Kidneys (Figure 1-5) 1. Extract and remove metabolic waste from the blood; blood pressure provides the force 2. Size and shape vary according to the species; ma- jority are bean shaped 3. Right kidney is more firmly attached and cranial to the left kidney 4. Microscopic unit is the nephron 5. Outercortex:containstheglomerulus,Bowman’s capsule, proximal convoluted tubules (PCTs), and distal convoluted tubules (DCTs) 6. Medulla: contains the loop of Henle and most of the collecting tubules 7. Medulla is arranged into various numbers of pyramids 8. Apex of the pyramid is the papilla, which opens into the minor calyx, major calyx, and renal pelvis B. Ureters 1. Consist of smooth muscle 2. Capable of peristalsis to move urine to the uri- nary bladder C. Urinary bladder 1. Consists of smooth muscle 2. Lined with transitional cell epithelium VetBooks.ir
- 28. Chapter 1 Animal Anatomy and Physiology 17 D. Urethra 1. Tube of smooth muscle to transport urine from the urinary bladder to the exterior II. Physiology: three phases to urine production A. Filtration 1. Blood enters glomerulus by the afferent arteriole 2. Various pressures cause water, salt, and small molecules to move out of the glomerulus into Bowman’s capsule a. The filtrate is now called the glomerular fil- trate; rate at which it is formed is called the glomerular filtration rate (GFR) B. Reabsorption 1. Occurs in the PCTs and loop of Henle;substances needed by the body are reabsorbed from the glo- merular filtrate into the peritubular capillaries C. Secretion 1. Substances are selectively secreted from the peri- tubular capillaries into the DCT III. Urination (micturition) A. The voiding of urine B. Filtrate flows into collecting ducts,renal pelvis,ureter, urinary bladder, and urethra and is voided as urine C. Urine is water plus waste products (e.g., urea, excess ions) IV. Hormonal influence A. Antidiuretic hormone (ADH [vasopressin]) 1. Increase in ADH release increases the reabsorp- tion of water within the kidney B. Aldosterone 1. Stimulates sodium reabsorption in the kidney Reproductive System: Male I. Male anatomy A. Testicles 1. Two oval glands in a skin-covered scrotum 2. Seminiferous tubules produce sperm 3. Interstitial cells of Leydig produce testosterone 4. Epididymis adheres to the side of the testicle; it connects the seminiferous tubules to the vas def- erens and provides storage for sperm and a place for maturation 5. Testicles develop inside the abdomen but de- scend into the scrotum (after birth in dogs and cats), where the body temperature is more favor- able for sperm development B. Vas deferens (ductus deferens) 1. Connects the epididymis to the urethra 2. Is a part of the spermatic cord, along with blood vessels and nerves 3. Spermatic cord passes through the inguinal ring; at this point, the vas deferens separates and joins the urethra C. Accessory sex glands 1. These glands produce semen 2. Semen provides a transport medium for sperm, protectsthespermagainsttheacidityinthefemale genital tract, and provides a source of nutrition 3. Glands vary with the species 4. Dogs have a prostate only 5. Cats have a prostate and bulbourethral (or Cowper’s) glands 6. Stallions have seminal vesicles (vesicular glands), prostate, bulbourethral glands, and ampulla D. Penis 1. Houses the urethra, which transports sperm into the female genital tract 2. Consists of a shaft and the tip, known as the glans penis 3. Erectile tissue surrounds the urethra; with sexual excitement the tissue becomes engorged with blood, leading to an erection, followed by the re- lease of sperm during ejaculation a. Penis of the cat, dog, and stallion is composed of mostly erectile tissue and a small amount of connective tissue b. Penis of the bull, ram, and boar is composed of mostly connective tissue and very little erectile tissue (1) These animals achieve erection by the straightening of the sigmoid flexure of the penis 4. Dog penis is unique in that it has a very long glans penis 5. Cat penis is retracted and covered with spiny epi- thelial projections Renal corpuscle Bowman's capsule Capsular space Glomerulus Efferent arteriole Afferent arteriole Distal convoluted tubule Branch of the renal artery Ascending loop of Henle Descending loop of Henle Peritubular capillaries Peritubular capillaries Proximal convoluted tubule Collecting duct Renal cortex Renal medulla Branch of the renal vein FIGURE 1-5 Microscopic anatomy of nephron. (From Colville T, Bassert JM: Clinical anatomy and physiology for veterinary technicians, ed 2, St Louis, Mosby, 2008.) VetBooks.ir
- 29. 18 PART l Anatomy and Veterinary Diagnostics 6. Both dogs and cats have a nonarticulating bone (baculum or os penis) II. Male physiology A. Follicle-stimulating hormone (FSH) is secreted from the pituitary, causing spermatogenesis to begin B. Spermatogonia in the testicle undergo meiosis; each cell will give rise to four mature sperm, each con- taining the haploid number of chromosomes C. Interstitial cell–stimulating hormone (ICSH) is secreted from the pituitary, causing the interstitial cells of Leydig to produce testosterone Reproductive System: Female I. Female anatomy A. Ovaries 1. Paired oval organs found in the abdomen 2. Produce ova and hormones B. Oviduct 1. Conducts ova from ovary to uterine horn or uterus (depending on the species) 2. Infundibulum: Funnel–shaped end of the ovi- duct, proximal to the ovary, helps direct ovum into the oviduct C. Uterine horns and/or uterus 1. Presence or absence of uterine horns varies with the species 2. In monotocous or uniparous (giving birth to one offspring at a time) animals, young develop in the body of the uterus 3. In polytocous or multiparous (giving birth to more than one offspring at a time) animals (dogs and cats), young develop in uterine horns D. Cervix 1. Cervix is the opening to the uterus; some spe- cies have a double cervix (e.g., rabbits) 2. Female reproductive system consists of the fol- lowing histological layers: a. Endometrium: epithelial cells, mucous membrane, and glands (1) Varies in thickness during the reproduc- tive cycle (2) Is reabsorbed in animals with an estrous cycle and sloughed in animals with a menstrual cycle (primates) b. Myometrium: smooth muscle c. Perimetrium: serous covering, which is con- tinuous with peritoneum E. Vagina (birth canal) F. Vestibule: Common duct for urine and fetus dur- ing parturition 1. Muscular tube from the cervix to the urethral orifice G. Vulva 1. The external genital organ 2. Many female animals have a common urogeni- tal pathway II. Female physiology A. Types of estrous cycles 1. Monestrous: usually one cycle per year, and usually in seasonal breeders (e.g., mink) 2. Diestrous: cycle in spring and fall (e.g., dog) 3. Polyestrous: more than one cycle per year (con- tinuous) (e.g., swine) 4. Seasonally polyestrous: cycle continuously in specific seasons (e.g., cat, horse, sheep) 5. Reflex or induced ovulators: ovulate after being bred (e.g., cat, rabbit, mink, ferret) 6. Spontaneous ovulator: ovulation occurs natu- rally regardless of coitus (e.g.,dog,cattle,horse) III. Estrous cycle A. Proestrus 1. Period of preparation 2. Female attracts the male but is not receptive 3. Under influence of FSH from the pituitary 4. New ovarian follicles grow and release estrogen, which builds up the uterus and uterine horns B. Estrus (“standing heat”): period of sexual receptivity 1. Female is sexually receptive to the male 2. Uterus and uterine horns are ready to receive an embryo 3. Release of luteinizing hormone (LH) from the pituitary causes ovulation in dogs 4. Cats and rabbits are nonspontaneous, or in- duced, ovulators and ovulate when bred; they have a longer estrus if not bred 5. Dogs may have a bloody discharge; cats exhibit behavioral changes (e.g., rubbing, lordosis, vocalization) C. Metestrus 1. Short postovulatory phase 2. Each ruptured follicle develops into a corpus luteum 3. Corpus luteum produces progesterone, which causes final maturation of uterine horns and/or uterus and inhibits development of new follicles D. Diestrus 1. Corpus luteum continues to secrete hormones 2. If pregnancy does not occur, the corpus luteum degenerates 3. If pregnancy occurs, the corpus luteum is main- tainedandcontinuestosecretehormones;insome species secretion occurs for the entire pregnancy, and in others only until the placenta is developed 4. Some animals remain in this stage and appear pregnant; this is known as pseudopregnancy E. Anestrus 1. Long period of inactivity in seasonally polyes- trous animals IV. Fertilization and pregnancy A. Copulation or coitus is the act of mating or sexual intercourse B. Male will mount the female and insert the penis; ejaculation deposits semen into the vagina VetBooks.ir
- 30. Chapter 1 Animal Anatomy and Physiology 19 C. Fertilization begins with the union of sperm and egg within the oviduct D. Zygote undergoes mitotic divisions as it is propelled through the uterine tubes and then implants in the uterine horns or uterus, depending on the species E. Fetal membranes form around the developing em- bryo for protection F. As the embryo grows, it develops a placenta and attaches to the endometrial lining of the uterus 1. The placenta forms to allow the exchange of nu- trients and waste products between mother and fetus (fetal and maternal blood do not mix) G. Between implantation and parturition, the devel- oping organism is called a fetus H. Protective fetal membranes 1. Amnion: forms a fluid-filled sac closest to the fetus; this is filled with amniotic fluid 2. Allantois: a two-layered membrane; one layer adheres to the amnion, the other layer to the chorion; fluid fills this cavity 3. Chorion: outermost layer, which attaches to the endometrium 4. Type of fetal attachment varies with species V. Parturition: act of giving birth A. Labor 1. Undertheinfluenceof oxytocinfromthepituitary, the uterus and/or uterine horns begin to contract 2. Delivery of fetus: fetus is pushed through the cervix and vagina 3. Delivery of placenta: placenta (afterbirth) is de- livered after the birth of each fetus VI. Gestation period: length of time from fertilization to birth A. Cat and dog: average 63 days B. Horse: average 336 days C. Cow: average 285 days VII. Dystocia: difficult birth A. May result in the need for a cesarean section B. Some species are more prone to dystocia C. May be result of maternal factors (conforma- tion (pelvic size, anatomical abnormalities, pri- mary inertia, secondary inertia) or fetal factors (presentation, position, posture, size, abnormal development) VIII. Lactation: milk production A. First milk is colostrum; contains antibodies, pro- teins, and vitamins and is important for the neonate B. Milk production is under the influence of prolac- tin from the pituitary Endocrine System Endocrine glands (Table 1-4) are ductless and produce chemical substances (hormones) that have a specific effect on a target area. The hormones are secreted directly into the bloodstream. I. Characteristics A. Hormones may: 1. Change the permeability of a cell Gland Hormone/Steroid Hormone Action Thyroid Thyroxin Calcitonin Accelerates metabolism Regulates calcium levels Parathyroid Parathormone Regulates calcium and phosphorus levels Adrenal cortex Glucocorticoids, mineralocorticoids, gonadocorticoids Protein and carbohydrate metabolism, stress resistance, antiinflammatory effects, regulates sodium and potassium levels, male and female sex hormones Adrenal medulla Epinephrine, norepinephrine Stimulate sympathetic nervous system; “fight or flight” Pituitary (master gland) Growth hormone Thyroid-stimulating hormone (thyrotropic) Adrenocorticotropic hormone (corticotropin) Follicle-stimulating hormone Luteinizing hormone (interstitial cell–stimulating) Prolactin Oxytocin Antidiuretic hormone (vasopressin) Stimulates growth Stimulates thyroid gland Stimulates adrenal cortex Growth of ovarian follicle Causes ovulation; stimulates testosterone production Stimulates lactation Causes uterine contractions Causes water reabsorption Pancreas Insulin Glucagon Decreases blood glucose Increases blood glucose Ovary Estrogen Progesterone Female sex characteristics Prepares uterus and uterine horns Testes Testosterone Male sex characteristics TABLE 1-4 Endocrine Glands VetBooks.ir
- 31. 20 PART l Anatomy and Veterinary Diagnostics 2. Change the permeability of an organelle 3. Activate or inactivate an enzyme system 4. Change the rate of enzyme production II. Control A. Hormone secretion is most commonly regulated through a negative feedback system; as the hor- mone levels rise, their secretion is inhibited B. Only the adrenal medulla is under neural control Integumentary System Anatomy I. Skin consists of two layers of skin and one underlying layer of subcutaneous tissue (Figure 1-6) A. Epidermis 1. Superficial layer is the stratum corneum; this is a nonvascular, cornified layer, 20 to 30 rows of keratocyte “remnants,” constantly being shed and replaced 2. The next layer is the stratum lucidum. Found only in thick skin, this layer is composed of a few rows of flattened dead cells 3. The granular middle layer or stratum granulo- sum consists of two to four layers of flattened keratocytes that help waterproof the skin 4. The stratum spinosum contains several layers of cells held together by desmosomes, Langerhans’ cells found in this layer 5. The deepest layer is the actively growing stratum germinativum or stratum basale; contains mela- nocytes (pigment cells) B. Dermis (corium) 1. Deep to the epidermis 2. Contains arteries, veins, capillaries, lymphatics, and nerve fibers C. Hypodermis 1. Deep to the dermis is the subcutaneous layer consisting of connective and adipose tissue Function I. Protective barrier, sense organ, and site for vitamin D synthesis II. Contains many glands and nerve receptors (e.g., Meissner’s corpuscle [touch receptor], sweat glands, Ruffini’s endings [heat receptor], Pacini’s corpuscles [pressure receptor], sebaceous glands), melanocytes (pigment cells [produce melanin, giving skin its color]) Hair I. Hair contains an inner medulla covered by the thicker cortex, which in turn is covered by a keratinized layer called the cuticle II. Hair is produced within a follicle, with growth origi- nating in the bulb region FIGURE 1-6 Canine skin. (From Colville T, Bassert JM: Clinical anatomy and physiology for veterinary technicians, ed 2, St Louis, Mosby, 2008.) Compound follicle Scalelike folds Hair shafts Free nerve ending Sebaceous (oil) gland Sebaceous (oil) gland Arrector pili muscle Hair root Nerve Artery Vein Pacinian corpuscle Adipose (fat) tissue Meissner's corpuscle Epidermis Dermis Hypodermis VetBooks.ir
- 32. Chapter 1 Animal Anatomy and Physiology 21 III. The portion of a hair that is below the skin is known as the root; the region above the skin is the shaft IV. Number of hairs per follicle varies V. Each hair follicle is supplied with sebaceous glands and an arrector muscle of hair VI. Contraction of this muscle is responsible for the raised hairs seen in frightened cats and dogs VII. Types A. Normal guard or cover hair; usually accompanied by shorter wool hair in the same follicle B. Wool hair: shorter, wavy, no medulla (e.g., sheep) C. Tactile hairs (sinus hairs) (e.g., whiskers): used as feelers; very sensitive to movement Specialized Integument I. Horns, claws, and hooves grow from a specialized der- mis and consist of cornified epidermal cells Senses Vision I. Anatomy: eye A. Sclera: outermost fibrous layer of the eye (white of the eye) B. Uvea: vascular layer of the eye; consists of the iris, ciliary body, and choroid 1. Iris: colored, contractile membrane between the lens and the cornea; regulates amount of light passing through the pupil 2. Ciliary body: supports the lens; major site for the production of aqueous humor 3. Choroid:vascularcoatbetweenthescleraandretina C. Retina: Innermost layer, light sensitive, housing photoreceptors (e.g., rods and cones) D. Vitreous humor: clear gel that occupies the space between the lens and the retina E. Lens: focuses light onto the retina F. Iris: colored, contractile membrane between the lens and the cornea; regulates amount of light pass- ing through the pupil G. Pupil: opening in the center of the iris H. Aqueous humor: clear, watery fluid filling the an- terior and posterior chambers between the cornea and lens I. Cornea: transparent covering on the eye J. Conjunctiva: mucous membrane that lines the eyelids K. Nictitating membrane: third eyelid II. Lacrimal apparatus A. Tears from the lacrimal gland located in the upper eyelids flow onto the eyeball to flush debris from the eye and moisten and lubricate it B. Tears drain from a lacrimal duct in the medial can- thi of the upper and lower lids into the nasal cavity via the nasolacrimal duct III. Physiology A. Light passes through the pupil, is refracted by the lens, and hits the photoreceptors (i.e., rods and cones of the retina) B. Rods respond to dim light; more are present in noc- turnal animals C. Cones respond to bright light and color D. Nervous impulses from rods and cones are passed via the optic nerve to the brain Hearing I. Anatomy: ear; consists of three regions A. Outer ear 1. From the pinna up to and including the tym- panic membrane 2. Air filled B. Middle ear 1. Houses three ossicles: malleus (hammer), incus (anvil), and stapes (stirrup) 2. Air filled; communicates with the nasopharynx by way of the Eustachian tube C. Inner ear 1. Houses the cochlea and semicircular canals 2. Fluid filled 3. Cochlea houses the organ of Corti (hearing receptors) 4. Semicircular canals contain nerve receptors for perception of balance II. Physiology A. Sound waves are transmitted through the outer ear and strike the tympanic membrane B. Sound is concentrated and conducted through the three ossicles to the oval window, through the cochlea C. Cochlea houses the organ of Corti which, when stimulated, conducts a nervous impulse along the auditory nerve to the brain D. The round window allows room for the fluid in the cochlea to move III. Deafness A. Nerve deafness 1. Results from malfunction of receptors or audi- tory nerve 2. Most common in blue-eyed cats with white coats, Sealyham terriers, Scotch terriers, border collies, and fox terriers B. Transmission deafness 1. Results from malfunction in transmission of sound waves from outer to inner ear Smell I. Associated with the olfactory bulb in the rostral area of the brain II. Receptors lie in the mucous membranes of the nasal cavity III. Odor is dissolved in receptors and transmitted to the brain Taste I. Taste receptors are enclosed in gustatory papillae on the tongue VetBooks.ir
- 33. 22 PART l Anatomy and Veterinary Diagnostics II. Three types of gustatory papillae: fungiform, foliate, and vallate A. Fungiform papillae: mushroom shaped; scat- tered among filiform papillae on the surface of the tongue B. Foliate papillae: leaf shaped and found on the lat- eral borders of tongue (really parallel folds of lin- gual mucosa) C. Vallate (circumvallate) papillae: large, circular pro- jections surrounded by a cleft 1. Contain taste buds and serous glands in all do- mestic animals 2. Contain mucous glands in the horse III. Two other types of papillae are mechanical: filiform and conical A. Filiform: thorn shaped; help direct food toward pharynx and are used for lapping and grooming 1. These papillae are shorter and softer in the horse, hence the velvetlike tongue B. Conical (also lenticular papillae in ruminants): cone shaped; larger than filiform papillae ACKNOWLEDGMENT The author recognizes and appreciates the original work of Penny Rivait, on which this chapter is based. REVIEW QUESTIONS 1. Which of the following would be found in abundance in a skeletal muscle cell? a. Golgi complex b. Mitochondria c. Lysosomes d. Smooth endoplasmic reticulum 2. Which of the following uses active transport? a. Diffusion b. Osmosis c. Sodium-potassium pump d. Facilitated diffusion 3. Which of the following contains hyaline cartilage? a. Articular cartilage in a long bone b. The pinna of the ear c. Ligaments d. Pubic symphysis 4. The stomach is _________________ to the heart. a. Distal b. Rostral c. Cranial d. Caudal 5. Which of the following houses osteocytes in compact bone? a. Lacunae b. Haversian canal c. Lamellae d. Canaliculi 6. These striated cells are joined by intercalated disks and have a single, centrally located nucleus: a. Flat bone b. Smooth muscle c. Cardiac muscle d. Neurons 7. Schwann cells: a. Form myelin in the central nervous system b. Are part of the immune system c. Are supportive and protective only d. Are also known as the nodes of Ranvier 8. Which vessel contains oxygenated blood? a. Vena cava b. Jugular vein c. Pulmonary vein d. Pulmonary artery 9. During contraction, the electrical impulse in the heart travels through several structures. Which of the fol- lowing is the correct order of transmission? a. Purkinje fibers, bundle of His, SA node, AV node b. AV node, SA node, bundle of His, Purkinje fibers c. SA node, AV node, Purkinje fibers, bundle of His d. SA node, AV node, bundle of His, Purkinje fibers 10. Which part of the ECG is represented by the P wave? a. Atrial systole b. Ventricle systole c. Atrial diastole d. Ventricular diastole 11. Food travels through the stomach of the ruminant in what order? a. Reticulum, rumen, omasum, abomasum b. Rumen, reticulum, abomasum, omasum c. Rumen, omasum, reticulum, abomasum d. Rumen, reticulum, omasum, abomasum 12. In the digestive system, which cells produce the neces- sary hydrochloric acid? a. Parietal cells b. Chief cells c. Schwann cells d. Melanocytes 13. During inhalation, the diaphragm moves: a. Ventrally b. Dorsally c. Caudally d. Cranially 14. The outer cortex of the kidney contains all of the fol- lowing except: a. Bowman’s capsule b. Loop of Henle c. Proximal convoluted tubules d. Distal convoluted tubules 15. Which of the following hormones is responsible for stimulating the sympathetic nervous system? a. Epinephrine b. Calcitonin c. Thyroxin d. Prolactin VetBooks.ir
- 34. Chapter 1 Animal Anatomy and Physiology 23 16. The colored part of the eye is the: a. Pupil b. Lens c. Iris d. Cornea 17. The auditory ossicles are located: a. In the cochlea b. In the outer ear c. In the middle ear d. In the inner ear 18. ADH (vasopressin) causes water reabsorption and is released by which gland? a. Pituitary b. Adrenal medulla c. Adrenal cortex d. Spleen 19. Which of the following has a prostate but no bulbourethral gland? a. Cat b. Cow c. Dog d. Horse 20. Which of the following layers of skin contains “water- proofing” cells? a. Stratum corneum b. Stratum germinativum c. Stratum granulosum d. Corium BIBLIOGRAPHY Colville T, Bassert J: Clinical anatomy and physiology for veterinary technicians, St Louis, 2008, Mosby. Frandson RD,Wilke W, Fails AD: Anatomy and physiology of farm animals, ed 6, Philadelphia, 2003, Lippincott Williams Wilkins. Marieb E, Hoehn K: Human anatomy and physiology, ed 7, San Francisco, 2007, Pearson Benjamin Cummings. Martini F: Fundamentals of anatomy and physiology, ed 7, San Francisco, 2006, Pearson Benjamin Cummings. McBride DF: Learning veterinary terminology, ed 2, St Louis, 2002, Mosby. Romich JA: An illustrated guide to veterinary terminology, ed 2, Clifton Park, NY, 2006, Thomson Delmar Learning. Ruckebusch Y, Phaneuf L-P, Dunlop R: Physiology of small and large animals, St Louis, 1991, Mosby. Sherwood L, Klandorf H, Yancey P: Animal physiology from genes to organisms, Belmont, Calif, 2005, Thomson Brooks/Cole. VetBooks.ir
- 35. 24 Oreta M. Samples CHAPTER 2 Urinalysis and Hematology CHAPTER CONTENTS Urinalysis Specimen Collection and Handling Microscopic Evaluation Uroliths Hematology Blood Collection and Sampling Erythrocyte (Red Blood Cell) Evaluation Leukocyte (White Blood Cell) Evaluation Thrombocyte (Platelet) Evaluation Total Protein Instrumentation Acknowledgment Review Questions Bibliography KEY TERMS absolute acanthocyte agglutination aggregation agranulocyte anemia anisocytosis anuria azurophilic granules basophilia basophilic stippling bilirubin bilirubinuria buffy coat codocyte conjugated bilirubin continence crenation cylindruria cystocentesis dysuria endogenous substances eosinopenia erythropoiesis ethylenediaminetetraacetic acid (EDTA) exogenous substances glucosuria granulocyte hematuria hemoglobinuria hemolysis heterophil hyperchromasia hypersegmented hypersthenuria hypertonic hypochromic hyposthenuria incontinence isosthenuria ketonemia ketonuria left shift leptocyte leukemia leukocytosis leukopenia lymphocytosis macrocyte macrocytic mast cell microcyte microcytic micturition monocytosis myoglobinuria neutropenia neutrophilia new methylene blue (NMB) normochromic normocyte nucleated red blood cells (nRBC) oliguria packed cell volume (PCV) pH plasma poikilocytosis point-of-care testing (POCT) pollakiuria polychromasia polychromatophilia polycythemia polyuria postprandial proteinuria red blood cell (RBC) relative right shift rouleaux schistocyte smudge cell specific gravity (SG) spherocyte stomatocyte thrombocythemia thrombocytopenia thrombocytosis torocyte toxic neutrophils turbidity urinometer urobilin urobilinogen urolith white blood cell (WBC) VetBooks.ir
- 36. Chapter 2 Urinalysis and Hematology 25 Veterinarians and researchers depend on clinical labora- tory test results to complement the presenting complaint, history, and examination, thus offering the patient the best possible care. Consistent and accurate results provided by the veterinary technician are an essential component of this care. Whether the tests are performed in-house or forwarded to a reference laboratory, pre-analytical patient variables and care, specimen collection, handling, and tim- ing influence the results. URINALYSIS A complete urinalysis includes the evaluation of the physical, chemical, solute, and microscopic components of the urine and may include microbiological cultures and sensitivity testing, as well as identification of urinary calculi. I. The information gained from these evaluations is used to assess the urinary system and aid diagnosis of non–urinary tract disorders A. Whether searching for or confirming a diagnosis, screening for an asymptomatic disease during an annual health or presurgical examination, moni- toring the progress of a disease, or assessing the efficacy and safety of a treatment, urinalysis helps in patient evaluation 1. Urine testing is usually easily performed, requiring a minimum of supplies, diagnos- tic instrumentation, and veterinary techni- cian time B. Qualitative (and semi-quantitative) urine analysis 1. Outcome is not affected by rate of urine forma- tion or amount produced during a specific rate of time 2. Allows determination of excretion rate of vari- ous endogenous and exogenous substances by volume collected, as well as time during which collection takes place and condition of collection C. Endogenous substances include uric acid, amino acids, hormones, and electrolytes D. Exogenous substances are creatinine clearance and phenolsulfonphthalein dye II. Quantitative urinalysis A. Outcome is affected by volume collected, as well as time and condition(s) during collection Specimen Collection and Handling I. Containers A. Collect the specimen in a clean (preferably sterile and disposable), dry, opaque container to prevent contamination and degradation of the light-sensitive components (e.g., bilirubin and urobilinogen) 1. The container should be non-breakable and fit- ted with a tight lid after collection, to prevent contamination, spillage, or evaporation 2. Sterile containers should be used for urine samples collected by cystocentesis or catheter- ization for bacterial culture 3. The sterile aspiration syringe used for these procedures makes an acceptable container and should be immediately capped B. Timing of urine formation versus collection ver- sus analysis 1. Formation a. Because urine is stored in the bladder af- ter formation, the urine is not necessarily “fresh” on collection b. Deterioration of components may have occurred from the natural breakdown of formed elements, and may be influenced by the presence of bacteria and change in pH 2. Collection a. Fasted, postprandial, after rest, random ver- sus timed, singular versus serial b. A singular sample gives a“snapshot”in time, whereas a series of samples provides a “re- cord” of changes due to variation in activity c. A post rest sample will likely be more con- centrated than a sample collected after activ- ity and water consumption d. A 3- to 6-hour postprandial sample may be more reflective of the diet 3. Analysis a. Degradation occurs from the instant of for- mation and subsequent collection b. To be reliable and best reflect the patient’s condition, a urinalysis should be performed within 20 to 30 minutes of collection c. Point-of-care testing (POCT) should be considered for increased accuracy C. Methods of collection 1. Free flow (clean catch, spontaneous micturi- tion or voiding) LEARNING OBJECTIVES After reading this chapter you should be able to: 1. Describe, compare, and evaluate the various collection methods for urine and blood samples 2. Describe the various procedures for the evaluation of urine and blood samples 3. Explain the various components of the test results as they relate to the“normal”physiological and pathophys- iological patient 4. Identify and limit pre-analytical patient variables and care influences, specimen collection and handling, and timing influences that affect results VetBooks.ir
- 37. 26 PART l Anatomy and Veterinary Diagnostics a. Simple, noninvasive procedure but unsatis- factory for bacterial culture b. Preferably, a midstream sample is collected, avoiding initial or end portion of the voided urine c. Vulva or prepuce should be cleansed before collection d. Variations (1) Commercially available absorbable urine sponges (a) For chemistry and physical evalua- tion only (b) Not for microscopic urinalysis (2) Litter pan (a) Replace regular absorbable litter with inert non-absorbable litter (3) Manual expression (a) Must be performed with care and patience; avoid excessive pressure to the bladder (b) Should never be attempted on an animal with a suspected urethral obstruction (4) Metabolism cage (a) Usually of value to determine urine volume only (b) Extended time between collection and testing may increase the possi- bility of contamination and sample degradation (c) To assist in maintaining sample qual- ity, cold pack collection reservoirs are available, as are alarm-sensitive cages, which alert personnel to the presence of a sample (5) Tabletop, cage, floor (a) May be adequate for screening if the surface iscleanandfree of disinfectant residues,and the sample is analyzed in an expedient manner such as POCT (b) These samples are usually contami- nated, not suitable for bacterial cul- ture, and offer limited diagnostic information (6) Client-collected samples (a) Usually, client-collected samples are not satisfactory because of im- proper collection procedures, the extended time between collection and testing, and the use of im- proper containers and storage (b) Although not always practical, it is best to have the client bring the pa- tient to the clinic (c) Under these circumstances, the cli- ent should be asked to discourage the pet from voiding urine for 2 to 3 hours before the appointment to facilitate collection at the clinic 2. Cystocentesis a. Perform by inserting a needle through the ventral abdominal wall and into the urinary bladder b. Perform the procedure using aseptic tech- nique on a patient with a full bladder, thus providing a better anatomical reference and minimizing possible damage to other ab- dominal organs c. Collection through cystocentesis avoids contaminants from the lower portions of the urinary tract, making the sample suitable for bacterial culture 3. Transurethral catheterization a. Performed by passing a rubber, plastic, or metal catheter through the urethra and into the urinary bladder b. Type and size of catheter depends on size, gender, and species of animal c. Catheterize as aseptically and atraumatically as possible to avoid complications for the patient and catheter-induced cellular and bacterial contamination of the sample d. Sample is aspirated into a syringe attached to the exposed end of the catheter D. Preservation 1. For microscopic evaluation, centrifuge imme- diately 2. Refrigerate (~35° to 46° F [~2° to 8° C]) for an additional 2 to 12 hours if necessary, but bring sample to room temperature (~68° to 77° F [~20° to 25° C]) before evaluation, es- pecially if evaluating specific gravity (SG) and crystals a. Cold urine may also interfere with enzymatic reactions on the urine chemistry dipsticks 3. Freezing (≤32° F [≤ 0° C]) is satisfactory for common urine chemical analytes, but will most likely destroy the cellular elements 4. Chemicals a. The sample can be preserved by the addition of acidifiers (e.g., boric acid or hydrochloric acid), formaldehyde, toluene, thymol, phe- nol, chloroform, sodium fluoride, and com- mercial chemical urinary preservatives b. Although one or more urine elements may be preserved by the chemical, it may be at the expense of other elements in the urine E. Sample variables 1. Samples should be analyzed within 20 to 30 minutes of collection to maximize validity of information and minimize post collection ana- lytical variables VetBooks.ir
- 38. Chapter 2 Urinalysis and Hematology 27 2. One, more, or all results may be directly or in- directly influenced by non-pathological inter- nal and external influences (e.g., exercise, water intake, diet, medication, collection method, degree of restraint, environmental factors [e.g., temperature, humidity]) a. The veterinarian interprets individual test results in light of these variables, with the results of other urine and clinical evaluation procedures, and in concert with the physical examination and history 3. Pre-collection and post-collection (pre-analyt- ical), “artifactual” or iatrogenic variables may increase or decrease values, resulting in false- positive or false-negative results. 4. See Table 2-1 for variations that affect test results II. Physical evaluation A. Terms related to urine volume and output 1. Anuria: complete absence of urine formation or elimination a. Can occur from renal shutdown; usually as- sociated with obstruction 2. Continence: storage of urine in the bladder as it fills 3. Dysuria: difficulty or pain on urination 4. Incontinence: dribbling of urine at frequent intervals a. Commonly occurs in dogs because of con- genital abnormality of the ureters or urethra 5. Micturition: physiological term for emptying the bladder a. Commonly referred to as urination TABLE 2-1 Variation to Deterioration of Sample and Influences on Test Methods Component Variation Ammonia Increase from proliferation of urease-producing bacteria Bacteria Increase from the in vitro proliferation of bacteria that normally inhabit the vagina, labia, urethra, or prepuce or arise from urinary tract infections or contamination from external sources Bacterial concentration approximately doubles every hour at room temperature (~68°-77° F [~20°-25° C]) Bilirubin Decrease from exposure to light and oxidation at room temperature Casts Decrease due to alkalization (pH 7.0) or dilution of urine (SG~1.008-1.010) Color Darkens with exposure to light and urochrome degradation Brown-black discoloration with blood substitutes Crystals Types and numbers increase or decrease with pH and temperature changes (colder temperature causes increase) Erythrocytes Hemolysis caused by dilute and/or alkaline urine, or freezing Glucose Decrease from metabolism by cells or bacteria and/or from the inhibition of the enzymatic reaction on the chemistry strip if the urine is cold Hemolysis Increases as a result of the deterioration of the erythrocytes in alkaline or dilute urine blood Ketones May decrease with the presence of bacterial metabolism and volatilization of acetone Leukocytes Decrease with alkalization and/or dilution of urine, or freezing Nitrites Increase when bacteria convert nitrate to nitrite Decrease when nitrite is converted to nitrogen and evaporates Odor Becomes stronger from the ammonia produced from bacterial metabolism pH Usually increases (alkaline) with the presence of urease-producing bacteria and/or the loss of carbon dioxide Decreases (acidic) with the proliferation of non–urease-producing bacteria and yeasts converting glucose to acids Proteins Increase from bacteria proliferation, alkalization, contamination with chemicals (e.g., disinfectants: quaternary ammonium or chlorhexidine), some medications (check package insert), blood substitutes, anesthetics, or elevated body temperature Decrease with acidic urine Turbidity Develops from presence of bacteria, proliferation of crystals, or precipitation of amorphous material Somatic cells Deteriorate with rise in pH or freezing Urobilinogen Decreases on exposure to light Yeasts/fungi Increase from external contamination or resistant urinary tract infection VetBooks.ir
- 39. 28 PART l Anatomy and Veterinary Diagnostics 6. Oliguria: a decrease in the formation or elimi- nation of urine a. Occurs with shock, dehydration, water con- servation, renal failure, and insufficiency 7. Pollakiuria: refers to frequent urination a. Often confused with polyuria by clients 8. Polyuria: formation and excretion of large vol- umes of urine a. Associated with nephritis, diabetes mellitus, and polydipsia; may be an unreliable symp- tom in itself B. Volume: influenced by several factors, including water intake, environmental temperature, physical activity, size, species, diet, and medications C. Ideally, various sequential samples should be evalu- ated over 24 hours to determine the various inter- nal and external influences on urine volume and the other physical, chemical, and microscopic analytes D. Color 1. In most species, although urine is regarded as “yellow,”it may range in color from pale to am- ber colored a. Yellow is normally due to urochrome pigments b. Urobilinogen may also influence the color 2. Color generally correlates with SG (concentra- tion), volume, and pigments from internal or external sources a. Light-colored urine tends to have a lower SG; darker urine generally has a higher SG b. Bile pigments are likely contained in yellow- brown to greenish urine that foams when shaken c. Red or reddish-brown urine indicates hema- turia (red blood cells [RBCs]) or hemoglo- binuria (hemoglobin [Hb]) d. Brown urine may contain myoglobin from muscle cell breakdown (myoglobinuria) e. Medications and diet may influence color f. Increase in urine volume results in urine di- lution and lighter color g. Urine collected after a period of rest tends to be darker in color because of increased concentration 3. Some species have variable color of urine a. Rabbit urine commonly varies from yellow to cloudy-white to orange-red-brown due to porphyria pigments b. Horse urine is browner on standing due to oxidation E. Transparency (turbidity, cloudiness): presence of particulate matter 1. Transparency is described as clear, hazy, cloudy, turbid, opaque, or flocculent (large particulate matter that readily settles out) 2. Cloudy urine can be associated with the pres- ence of cellular debris, such as RBCs, white blood cells (WBCs), epithelial cells, crystals, bacteria, casts, mucus, semen, and lipids a. Bacterial proliferation or crystal forma- tion can cause urine to become cloudy on standing 3. Normal freshly voided urine in many species is clear; exceptions include: a. Horse, because of the presence of calcium carbonate crystals and mucus secreted by glands in the renal pelvis b. Rabbit, hamster, and guinea pig, because of the presence of calcium salts c. Feline urine commonly is slightly cloudy, because of the presence of fat d. On standing, urine typically becomes more cloudy with the increased number of bacte- ria and possible formation of crystals (e.g., calcium carbonate crystals form in cattle urine) 4. Microscopic evaluation is necessary to distin- guish possible causes of turbidity III. Odor A. Not highly diagnostic; varies with species and gen- der of the patient 1. Odors are commonly described as a. “Normal” (characteristic for the species and gender) b. Ammoniacal (urease-producing bacteria) c. Putrid (bacterial degradation of protein) d. Fruity or sweet (e.g., ketones, glucose) e. “Disagreeable” 2. Strong urine odor is typical in mice and intact male cats, goats, and pigs 3. In some cases, a sweet or fruity odor can in- dicate the presence of ketones (ketonuria) and is commonly associated with diabetes mellitus, pregnancy toxemia in sheep, or acetonemia (ketosis) in cows 4. Ammonia is due to bacterial proliferation, which may be from infectious or contaminat- ing organisms, and will result in increased odor on standing a. It may be indicative of improper storage rather than the health of the patient 5. Odormaybeinfluencedbydietandmedications IV. Specific gravity (SG, urine specific gravity [USG]) A. Density of a liquid compared with that of distilled water 1. In practical applications, it is used to assess the ability of the renal tubule to concentrate or dilute filtrates from the glomerulus, indi- cating how well the kidney can maintain water and osmotic balance VetBooks.ir
- 40. Chapter 2 Urinalysis and Hematology 29 2. The urine SG is interpreted by the veterinarian in concert with the patient’s hydration status, and blood urea nitrogen and serum creatinine levels 3. Urine density decreases as temperatures increases 4. Urine temperature is a factor when measuring SG B. Terms related to SG 1. -sthen (strength), iso- (the same as), hypo- (less than), hyper- (greater than) 2. Isosthenuria (“fixed SG” [SG ~1.008 to 1.012]) a. The glomerular filtrate has the same SG as the plasma. The urine has been neither di- luted nor concentrated in the renal tubules 3. Hyposthenuria (SG~1.008) a. Tubules are diluting the urine below the SG of plasma b. Osmolality measurement is less than that of plasma 4. Hypersthenuria (baruria [SG~1.012]) a. Tubules are concentrating the urine above the SG of plasma b. Osmolality measurement is more than that of plasma 5. Maximum urine concentration (SG) values a. Species-specific maximum concentration capacity of the tubules 6. Functionally adequate urine concentration (SG) values a. Species-specific sufficient concentrating ability, suggesting a sufficient number of “normally”functioning nephrons to prevent azotemia (presence of nitrogen wastes [e.g., urea, creatinine] in the blood) assuming re- nal blood flow is sufficient and there are no other influencing factors to impair the func- tion of the nephrons 7. Inappropriate urine concentration (SG) values a. Values below the questionable range 8. Questionable SG values a. Values marginally below the functionally ad- equate range C. Normal (reference) SG values vary and fluctuate widely from day to day and within the same day and are related to the individual, species, diet, ac- tivity, water, and electrolyte balance of the body, as well as possible pathologies 1. A single value within the normal or outside the normal range for an individual or the species does not necessarily reflect renal function or dysfunction D. Methods of SG evaluation 1. Refractometer (total solids [TS] meter) a. Solute in the urine bends light pass- ing through the urine to a degree that is proportional to the concentration of the solute b. Approximately measures SG or total solids of urine c. Refractometers are calibrated within a spe- cific temperature range; operating outside of this range may cause erroneous results; check manufacturer’s instructions d. Ensure that results are read from the SG scale, which differs by species, and from the total protein and refractive index scales e. To approximate the SG if the reading is off the scale; dilute the urine 1:1 with distilled water and adjust results accordingly by mul- tiplying the last two digits of the reading by 2 (1) For example, a urine sample diluted 1:1 with distilled water with a reading of 1.030 will have a SG of 1.060 (2×30) when adjusted for the 1:1 dilution. Do not attempt to make the dilution on the refractometer, because of the difficulty of obtaining an even mixture of urine and distilled water f. The relative specific refractivity of the urine of cats, rabbits, and guinea pigs differs from that of dogs, large animals, and humans (1) Therefore the commonly used human- based urine SG scale will give falsely el- evated SG results for cats and falsely low SG results for guinea pigs and rabbits (2) Preferably, use refractometers with scales calibrated for the specific species g. Glucose, protein (albumin), radiopaque dyes, urea, sodium chloride, and some an- tibiotics will raise the SG value (e.g., ~0.004 for each gram of glucose per deciliter of urine, and ~0.003 for each gram of protein per deciliter of urine) (1) To correct the SG, subtract the relevant increase for each gram of analyte (e.g., protein or glucose) per deciliter of urine h. Quality control: check the zero setting/cali- bration of the refractometer daily with dis- tilled water (1.000 SG [±0.05%]) and with a known control (5% NaCl solution=1.022 SG [±0.001]) (1) Adjust refractometer according to man- ufacturer’s instructions 2. Urinometer a. A “hydrometer” calibrated for urine b. When the urinometer is placed in a cylinder filled with urine, it will displace a volume equal to its weight (1) Therefore the more solute present in the urine, the less volume will be displaced and the higher the urinometer will float, denoting a higher SG VetBooks.ir
- 41. 30 PART l Anatomy and Veterinary Diagnostics c. Requires a large volume of urine (~5 to 15+ mL), whereas the refractometer requires only a drop or two d. Read results at bottom of the meniscus on the urinometer float e. Urinometer is calibrated to read samples at room temperature; correct the SG read- ing for the urine if the temperature of the urine is not at the calibrated temperature of the urinometer. Check manufacturer’s instructions f. Quality control (1) Check the accuracy of the urinometer with distilled water (SG 1.000) at the calibrated temperature 3. SG reagent test strips a. An indirect colorimetric method in which an increased color change is correlated with increased concentration of ionic solutes b. Developed for use with human urine samples c. Least reliable method of determining SG in animals, especially if SG is greater than 1.030, the upper limit of the test strips (1) High concentrations of protein or ke- tones may give falsely elevated values, whereas alkaline or dilute urine (low SG) may give false low values and high urine lipid content may either raise or lower values d. Not influenced by the presence of glucose or urea (1) Read results by comparing color changes with color scale on container e. See specific manufacturer’s instructions 4. Osmometry a. Unit: milliosmol/kg [L]=mOsm/kg [L] b. Likely the most representative method of an- alyzing urine solute osmolar concentration c. Measures number of dissolved particles in the urine (1) Costly instrumentation (osmometers) and time-consuming method, therefore more likely used in research and refer- ence laboratories d. Urine osmolality can be roughly “guessti- mated”from the USG by multiplying the last two digits of the urine SG (USG) by 36 (e.g., USG: 1.030≅1080 [30×36] mOsm/kg [L]) E. Urine SG values 1. Commonly reported SG values (Table 2-2) 2. Increased SG occurs with dehydration, de- creased water intake, acute renal disease, and shock a. In these situations, it would be expected that SG would be consistently higher than ~1.035 in the feline, 1.030 in the canine, and 1.025 in large animals b. Decreased SG occurs with increased fluid in- take and in renal and other diseases Chemical Components I. Urine pH A. Used togenerallyassessthe body’sacid-basebalance 1. pH number expresses the hydrogen ion (H+ ) concentration or the acidity a. pH 7 is decreased pH, or acid urine b. pH 7 is increased pH, or basic or alkaline urine B. Reagent strips are most commonly used to deter- mine pH; after being dipped into urine sample, the color change is compared with the color on a scale on the container 1. Common findings are between pH5.5 and 8.5 across species C. pH is often affected by diet 1. Herbivores commonly have an alkaline pH (~7 to 8.5); nursing herbivores commonly have more acid urine 2. Carnivores have an acidic pH (e.g., feline ~6 to 7) 3. Urine of omnivores may be either acidic or basic 4. Urine tends to become less acid after meals, be- cause of the “alkaline tide” (postprandial gas- tric secretion of hydrochloric acid) D. Loss of carbon dioxide occurs when samples are left open and standing at room temperature, re- sulting in higher pH readings TABLE 2-2 Commonly Reported Specific Gravity Values Species Approximate possible maximum range Common (daily variable-functional) range Questionable (marginal) to adequate values* Canine ~1.001-1.075 ~≥1.015-1.045 ~1.0301.040+ Feline ~1.001-1.085 ~≥1.035-1.060 ~1.0351.045+ Large animals ~1.001-1.040 ~≥1.015-1.030 ~1.025+ *Consistent successive results at the low end of or below these values from samples collected at various times throughout the day may indicate a disorder and would most likely be considered an “inappropriate” value. VetBooks.ir
- 42. Chapter 2 Urinalysis and Hematology 31 E. Standing urine, containing urease-producing bac- teria, also increases the reading F. In highly acidic urine, a false reduction of the pH reading may result because of dripping from the protein pad onto the pH pad. Therefore technique and timing are critical. See package insert II. Protein: A. Proteinuria usually describes an abnormal level of proteins or protein metabolites in the urine 1. Important indicator of renal diseases such as glomerulonephritis, amyloidosis, and nephrosis 2. When coupled with presence of renal casts may indicate renal disease B. Small amounts of protein pass through the glom- erulus, but most are resorbed by the renal tubules C. Detection of protein levels is commonly made with a reagent test strip that generates a color comparison. Results are recorded as milligrams per deciliter of protein detected 1. Lower limits of detection: ~30 to 50mg/ dL; which is specific for relatively increased amounts of albumin D. The results for the healthy patient are none or trace (10mg/dL), and the veterinarian will inter- pret the protein results in concert with the urine E. Results are considered semi-quantitative because of variables in chemical reaction and color chart comparison F. Errors can occur 1. False-positive or falsely elevated values may result when the urine is alkaline and highly concentrated, if the test strip is left in contact with the urine for an extended period, or if not read at the appropriate time; check the package insert a. False-negative results can occur if protein- uria is caused by globulins, or Bence-Jones protein (indicative of multiple myeloma) rather than albumin, or if protein is present in dilute or acidic urine 2. Depending on the reader and individuality in color determination, different values may be obtained 3. Proteinuria in diluted urine indicates greater protein loss than in concentrated urine 4. Small amounts of albumin may go undetected with routine chemistry dipstick tests G. Proteinuria results from several pre-renal and post-renal causes H. Values must be taken in context with hematology and chemistry results, other urinalysis results, or other methods of evaluating protein levels 1. Urine protein–to–creatinine (UPC) ratio (lower limits of detection: ~≥5 mg/dL) reflects the amount of protein excreted over 24 hours based on a single urine sample 2. Sulfosalicylic acid turbidometric test (lower limits of detection: ~≥5 to 10 mg/dL) a. Detects globulins and Bence-Jones protein in addition to albumins b. Used as a confirmatory test for chemistry test strip positive results, especially samples with an alkaline pH 3. Micro albumin test (lower limits of detection: ~≥1 mg/dL); detects small quantities of albu- min in the urine a. Micro albumin level has been associated with a variety of non-renal and renal dis- eases, including being an indicator of early glomerular renal disease b. The full extent of the usefulness of this test is still under study c. Currently, the available efficacious tests in veterinary medicine are species-specific im- munological (enzyme linked immunosor- bent assay [ELISA]) tests (1) Human MA test strips do not com- pletely match the results of the species- specific veterinary tests III. Glucose A. Detectable levels of sugar are referred to as glycosuria and depend on glucose levels in the blood 1. Glucose is not commonly detected in healthy animals; it passes through the glom- erulus and is resorbed in the proximal renal tubules a. Unless the renal threshold is reached (e.g., ~170 to 180 mg/dL [6.8 mmol/L] in dogs), glycosuria does not usually occur b. Therefore, unless there is excess of glucose reaching the tubules that cannot be resorbed or there is a functional deficit of the tubules, glucose will not be detectable B. Testing is usually performed with reagent test strips to detect glucose, and/or reagent tablets to detect sugars (glucose and other reducing sugars) in the urine 1. If the proteinaceous labile enzymes found in the glucose test pads become inactive, a false- negative result occurs C. Check with the manufacturer for details on pro- longing the life of unopened, in-date packages by freezing D. Hyperglycemia along with glucosuria can be at- tributed to diabetes mellitus created by insulin deficiency or function 1. For confirmation of diabetes mellitus, blood glucose level should be evaluated E. Other factors, such as fear, stress, excitement, in- travenous infusion of glucose, and other diseases also cause glycosuria VetBooks.ir
- 43. 32 PART l Anatomy and Veterinary Diagnostics 1. Fasting is recommended before glucose testing to avoid higher levels after a high-carbohydrate meal a. False-positive results can occur after the use of various drugs, such as salicylates, ascorbic acid, and penicillin IV. Ketones A. Any compound containing a carbonyl group and carbon monoxide and having a carbonyl group containing a chain of carbon atoms 1. Ketone bodies include acetone, acetoacetic acid, and β-hydroxybutyric acid a. Acetone and β-hydroxybutyric acid are de- rived from acetoacetic acid and result from the catabolism of fatty acid b. Usually, ketones are filtered by the glomeru- lus and reabsorbed by the tubules c. Ketones are produced during fat metabo- lism and are important sources of energy d. Excessive ketones are toxic, producing central nervous system depression and acidosis B. In normal animals, very small amounts are found in the blood 1. If there is increased fat metabolism, excess ke- tones spill into the urine, causing ketonuria 2. Ketonuria may occur as a result of incomplete reabsorption by the proximal renal tubules 3. Ketonemia (excess ketones in circulation [keto- sis, acetonemia]) results in ketonuria C. Commonly, in large animals, ketosis (pregnancy toxemia) is associated with hypoglycemia conse- quential to high glucose demands, resulting in in- creased fat metabolism 1. Typically occurs in early lactation or late preg- nancy, whereas in small animals, ketosis occurs with diabetes mellitus; lack of insulin prevents carbohydrate utilization D. Several reagent test strips or separate reagent tab- lets can be used to measure ketone levels 1. Color intensity is proportional to ketone concentration 2. These tests are most sensitive to acetoacetic acid and acetone V. Bile pigments A. Commonly detected bile pigments include biliru- bin and urobilinogen 1. Only conjugated bilirubin is found in the urine 2. A small amount of urobilinogen, from the breakdown of bilirubin (as a result of hemo- globin breakdown) by bacteria in the intestines, is excreted into the urine 3. Excessive quantities of bilirubin is known as urobilinuria or bilirubinuria B. Determination of bile pigments is made with re- agent test strips and tablet tests, with the tablet tests being more accurate 1. A rough determination of the presence of bilirubinuria can be determined if urine is shaken and a yellow foam forms 2. Positive bilirubin test pads in cats are usually reliable, whereas in dogs there can be a signifi- cant number of false-negative and false-positive results a. Urobilinogen is not easily detected; there- fore urobilinogen test pads in both dogs and cats have not been always reliable C. Bilirubinuria can be seen in several diseases, in- cluding biliary obstruction, hepatic infections, toxicity, and hemolytic anemia 1. Light will oxidize bilirubin if urine is left stand- ing, resulting in a false-negative result 2. Because the liver and kidneys of dogs and cattle have an enzyme that can conjugate bilirubin, slight bilirubinuria may be normally present in these species VI. Blood A. Presence of intact RBCs in the urine is referred to as hematuria, whereas the presence of free hemo- globin is hemoglobinuria and presence of myoglo- bin is myoglobinuria 1. Hematuria, hemoglobinuria, and myoglobin- uria change the color of urine from pink to red to brown a. A crude method to distinguish between myoglobinuria and hemoglobinuria is to evaluate the plasma/serum for the presence of hemolysis (1) If the urine and plasma/serum are fresh and both are reddish, hematuria is most likely present (2) Colorless plasma is indicative of myo- globinuria, because myoglobin does not emit a color in the plasma (3) Myoglobinuria is accompanied by intact red blood cells; an elevated plasma/serum creatine kinase (CK) may also suggest the possibility of myoglobin in the urine, because an increase in both may indicate insult to muscle tissue (4) In severe cases, urine may be almost black b. To distinguish hematuria from hemoglobin- uria and myoglobinuria (1) Pre-centrifugation:with hematuria,urine is cloudy because of the presence of intact erythrocytes (2) Post-centrifugation of the urine c. The supernatant will remain colorless in the case of hematuria d. If hemoglobinuria and myoglobinuria are present, the urine supernatant will still be reddish VetBooks.ir
- 44. Chapter 2 Urinalysis and Hematology 33 B. Occult blood may also be present, with no visible changes to the urine C. Hematuria is associated with disease of the uro- genital tract 1. Hemoglobinuria indicates some intravascular hemolysis a. Caution: post collection hemolysis occurs with improperly handled or stored urine 2. Myoglobinuria generally indicates a pathologi- cal condition of muscle or overexertion D. Besides color interpretation, blood or blood com- ponents in the urine are detected with reagent strips as well as tablets 1. Because these do not differentiate the cause of blood in urine, microscopic evaluation to de- termine RBC number, animal history and ex- amination, and other tests should be included in the evaluation process VII. Nitrite level in urine in humans is used as an indirect indication of bacteruria A. It is believed that ascorbic acid normally presents in canine and feline urine and usually gives false- negative results B. Bacterial cultures and microscopic evaluation of fresh urine samples are the best methods for de- tecting the presence of bacteriuria VIII. Leukocyte tests are designed to detect the presence of leukocyte esterase, found in all types of white blood cells, except lymphocytes A. False-positive results for cats and false-negative results for dogs are common; therefore it is best to evaluate fresh urine samples microscopically for the presence of leukocytes B. In addition, false-negative results may occur in pa- tientswithglycosuriaandelevatedUSG,andinthose treated with certain antibiotics (e.g., tetracycline) C. Falsely elevated results have been observed in old samples and those contaminated with feces D. Check package insert IX. Urobilinogen is formed in the gastrointestinal (GI) tract by anaerobic bacteria breaking down conjugated bilirubin, with small amounts eliminated in the urine and the majority in the feces A. When elevated, the test may be indicative of liver or GI tract dysfunction or intravascular hemolysis 1. Because of the instability of urobilinogen, false- negative results have been observed in acidic urine, old samples, and those exposed to light and air 2. False-positive results have been observed when the reagent strips have been stored close to a heat source 3. Unlike in humans, a significantly increased urobilinogen level with the chemistry dip- stick has not been observed in most patients; therefore the usefulness of the test in animals is questionable Microscopic Evaluation Examination of the urine sediment is highly valuable when used with the urine physical and chemistry tests, and he- matology and serum/plasma chemistries. Microscopic evaluation may be considered a form of exfoliate cytology. I. Sample preparation A. Best sample is obtained after a period of extended rest,becauseitismorelikelytobehighlyconcentrated B. Refrigerate the sample if it cannot be examined within 20 to 30 minutes. Room temperature stor- age can result in bacterial growth, natural chemi- cal breakdown, and cell lysis C. Thoroughly mix the specimen, transfer to a conical- tipcentrifugetube,andcentrifugesampleatthespeed and time specified by the centrifuge manufacturer 1. At least 5mL fresh urine is ideal,but“micro”meth- odsandcontainersareavailableforsmallersamples D. Notethevolumeof sediment;leaveasmallamountof the supernatant and resuspend the sediment by gen- tly tapping the bottom of the tube with your finger 1. Using a pipette, transfer a small drop of urine to a clean microscope slide and examine (Note: Do not use a wooden stick, because cells and other constituents commonly adhere to the stick) a. Cover-slipping is optional, based on experi- ence and personal preference b. Viewing of stained (e.g., wet: Sternheimer- Malbin, 0.5% new methylene blue [NMB]) or unstained urine is based on experience and personal preference (1) If staining is done, do not attempt to mix the stain on the slide with the urine. Mix in the tube for the best suspension of stain and urine (2) The type of stain will specifically influ- ence the appearance of the microscopic elements. Use an unstained sample to distinguish between stain artifacts and urine constituents (Figure 2-1) (3) Diff-Quik also can be used for stained urine preparation, with films prepared in methods similar to blood and other cytology films. Because urine is a fluid with typically low protein content, it may be washed off the slide in the stain- ing process. Use of serum-coated slides may limit the loss of supernatant E. Reduce illumination (lower condenser), view en- tire area under the coverslip through a 10× (low power field [LPF]) objective and then through a 40× (high power field [HPF]) objective F. Crystals and cast numbers are typically estimated as the average number per LPF 1. Epithelial cells and blood cells are estimated as the average number per HPF 2. Bacteria and sperm are noted as few, moderate, or many under HPF VetBooks.ir
- 45. 34 PART l Anatomy and Veterinary Diagnostics G. Contaminated or unrefrigerated “stale” samples should be avoided 1. Samples that have not been thoroughly re- suspended after centrifugation may yield a non-representative sediment 2. Sediments that were allowed to dry on the mi- croscope slide may make cells unrecognizable 3. Stain precipitate may mimic cells and crystals a. Use fresh stain b. Strain stain to remove precipitate matter II. Components of sediment (Figure 2-2) A. Normally, very few WBCs (leukocytes) are found (Figures 2-3 and 2-4) 1. Most cells in urine are neutrophils, which ap- pear spherical, granular, and larger than RBCs, but smaller than epithelial cells 2. Excessive number of WBCs is referred to as py- uria or leukocyturia 3. An increased number indicates active inflam- matory disease along the urinary tract, but also can be contaminants from the genital tract 4. More than a few (5 to 8 per HPF) should be regarded as abnormal and investigated further 5. Note any evidence of bacteria B. The number of RBCs (erythrocytes) is also nor- mally small (Figures 2-3 and 2-5) 1. Excessive number of RBCs is referred to as hematuria 2. Hematuria is associated with trauma, calculi, infection, and benign or malignant neoplasia 3. RBCs appear as pale yellow refractive discs, usu- ally uniform in shape and smaller than WBCs a. Sample manipulation can create distortion, crenation, hemolysis, and confusion with fat or yeast (1) Fat droplets (Figure 2-6) will float in and out of planes of focus; RBCs do not. Additionally, fat drops usually vary more in size, do not take on a crenated appear- ance, and will stain shades of iridescent orange with Sudan III or IV stain (2) If a small amount of 2% acetic acid is added to the slide and the structures disappear, they were RBCs 4. In concentrated urine, RBCs may lose fluid and become crenated (shrunken and spiked) a. In dilute urine they may swell or lyse, be- coming ghost cells A B C FIGURE 2-1 A, Cattle urine (epithelial cells and artifacts). B, Cattle urine (artifactual plant material). C, Cattle urine (unidentified pollen). VetBooks.ir
- 46. Chapter 2 Urinalysis and Hematology 35 R CR W S T RT DW C H FG C WBC F R W A U C AP B S C T A CC CO B H F S M Y A FD A B C D E F FIGURE 2-2 Common components of urine sediment. A, Caudate cells (C), crenated red blood cell (CR), degenerated white blood cell (DW), red blood cell (R), renal tubular (RT), squamous (S), transitional (T), white blood cell (W). B, Casts. Coarse granular (C), fatty (F), fine granular (FG), hyaline (H), red blood cell (R), waxy (W), white blood cell (WBC). C, Amorphous urates (A), calcium oxalate monohydrate (C), uric acid (U). D, Amorphous phosphate (AP), bilirubin (B), cystine (C), struvite/triple phosphate (S), tyrosine (T). E, Ammonium biurate/“thorn apple” (A), calcium carbonate (CC), calcium oxalate dihydrate “envelope” (CO). F, Air bubbles (A), bacteria (B), fungi (F), fat droplets (FD), hair (H), mucus (M), sperm (S), yeast (Y). (Drawings by Toni D’amato-Scheck, AAS, LVT; from Walsh D, D’amato-Scheck T, editors: Clinical technician lab manual, State University of New York at Delhi, Delhi, NY, 2001.) VetBooks.ir
- 47. Exploring the Variety of Random Documents with Different Content
- 48. colour of the slag on which they lay, he approached the bag which covered the body. What the devil is this? he cried out, and gave the bag a kick, throwing it clear of the thing which it covered. The bird on the bough atop of the slope trilled louder; the song of the man died out, and he turned to the ganger who stood near him, with a questioning look. It's Mick, is it? he asked, removing his cap. It's Micky, said the ganger. The man by the corpse bent down again and covered it up slowly and quietly, then he sank down on the green slope and burst into tears. Micky and him's brothers, you know, said a man who stood beside me in a whisper. The tears came into my eyes, much though I tried to restrain them. The tragedy had now revealed itself in all its horrible intensity, and I almost wished to run away from the spot. After a while the breakdown van came along; the corpse was lifted in, the brother tottered weakly into the carriage attached to the van, and the engine puffed back to Glasgow. A few men turned the slag in the sleeper beds and hid the dark red clotted blood for ever. The man had a wife and several children, and to these the company paid blood money, and the affair was in a little while forgotten by most men, for it was no man's business. Does it not give us an easy conscience that this wrong and that wrong is no business of ours? When the train rumbled around the first curve on its return journey I went towards the ganger, for the work obsession still troubled me. Once out of work I long for a job, once having a job my mind dwells on the glories of the free-footed road again. But now I had an object in view, for if I obtained employment on the railway I could stop in Glasgow and continue my search for Norah Ryan during the spare hours. The ganger looked at me dubiously, and asked my age.
- 49. Twenty-two years, I answered, for I was well aware that a man is never taken on as a platelayer until he has attained his majority. There and then I was taken into the employ of the —— Railway Company, as Dermod Flynn, aged twenty-two years. Afterwards the ganger read me the rules which I had to observe while in the employment of the company. I did not take very much heed to his droning voice, my mind reverting continuously to the tragedy which I had just witnessed, and I do not think that the ganger took very much pleasure in the reading. While we were going through the rules a stranger scrambled up the railway slope and came towards us. I heard that a man was killed, he said in an eager voice. Any chance of gettin' a start in his place? This man's in his shoes, said the ganger, pointing at me. Lucky dog! was all that the man said, as he turned away. The ganger's name was Roche, Horse Roche—for his mates nicknamed him Horse on account of his enormous strength. He could drive a nine-inch iron spike through a wooden sleeper with one blow of his hammer. No other man on the railway could do the same thing at that time; but before I passed my twenty-first birthday I could perform the same feat quite easily. Roche was a hard swearer, a heavy drinker, and a fearless fighter. He will not mind my saying these things about him now. He is dead over four years.
- 50. CHAPTER XX BOOKS For me has Homer sung of wars, Æschylus wrote and Plato thought, Has Dante loved and Darwin wrought, And Galileo watched the stars. —From The Navvy's Scrap Book. Up till this period of my life I had no taste for literature. I had seldom even glanced at the daily papers, having no interest in the world in which I played so small a part. One day when the gang was waiting for a delayed ballast train, and when my thoughts were turning to Norah Ryan, I picked up a piece of paper, a leaf from an exercise book, and written on it in a girl's or woman's handwriting were these little verses:
- 51. No, indeed! for God above Is great to grant, as mighty to make, And creates the love to reward the love,— I claim you still, for my own love's sake! Delayed it may be for more lives yet, Through worlds I shall traverse, not a few— Much is to learn and much to forget Ere the time be come for taking you. I have lived (I shall say) so much since then, Given up myself so many times. Gained me the gains of various men, Ransacked the ages, spoiled the climes; Yet one thing, one, in my soul's full scope, Either I missed or itself missed me: And I want and find you, Evelyn Hope What is the issue? let us see! While hardly understanding their import, the words went to my heart. They expressed thoughts of my own, thoughts lying so deeply that I was not able to explain or express them. The writer of the verse I did not know, but I thought that he, whoever he was, had looked deep into my soul and knew my feelings better than myself. All day long I repeated the words to myself over and over again, and from them I got much comfort and strength, that stood me in good stead in the long hours of searching on the streets of Glasgow for my luckless love. Under the glaring lamps that lit the larger streets, through the dark guttery alleys and sordid slums I prowled about nightly, looking at every young maiden's face and seeing in each the hard stare of indifference and the cold look of the stranger. Round the next corner perhaps she was waiting; a figure approaching reminded me of her, and I hurried forward eagerly only to find that I was mistaken. Oh! how many illusions kept me company in my search! how many disappointments! and how many hopes. For I
- 52. wanted Norah; for her I longed with a great longing, and a dim vague hope of meeting her buoyed up my soul. And I want and find you, Evelyn Hope! What is the issue? let us see! Such comforting words, and the world of books might be full of them! A new and unexplored world lay open before me, and for years I had not seen it, or seeing, never heeded. I had once more the hope that winged me along the leading road to Strabane when leaving for a new country. Alas! the country that raised such anticipations was not what my hopes fashioned, but this newer world, just as enticing, was worthy of more trust and greater confidence. I began to read eagerly, ravenously. I read Victor Hugo in G—— Tunnel. One day a falling rail broke the top joint of the middle finger of my left hand. Being unable for some time to take part in the usual work of the squad I was placed on the look-out when my gang worked on the night-shift in the tunnel at G——. When the way was not clear ahead I had to signal the trains in the darkness, but as three trains seldom passed in the hour the work was light and easy. When not engaged I sat on the rail beside the naphtha lamp and read aloud to myself. I lived with Hugo's characters, I suffered with them and wept for them in their troubles. One night when reading Les Miserables I cried over the story of Jean Valjean and little Cosette. Horse Roche at that moment came through the darkness (in the tunnel it is night from dawn to dawn) and paused to ask me how I was getting along. Your eyes are running water, Flynn, he said. You sit too close to the lamp smoke. I remember many funny things which happened in those days. I read the chapter on Natural Supernaturalism, from Sartor Resartus, while seated on the footboard of a flying ballast train. Once, when Roche had left his work to take a drink in a near public-house, I read
- 53. several pages from Sesame and Lilies, under shelter of a coal waggon, which had been shunted into an adjacent siding. I read Montaigne's Essays during my meal hours, while my mates gambled and swore around me. I procured a ticket for the Carnegie Library, but bought some books, when I had cash to spare, from a second-hand bookseller on the south side of Glasgow. Every pay-day I spent a few shillings there, and went home to my lodgings with a bundle of books under my arm. The bookseller would not let me handle the books until I bought them, because my hands were so greasy and oily with the muck of my day's labour. I seldom read in my lodgings. I spent most of my evenings in the streets engaged on my unsuccessful search. I read in the spare moments snatched from my daily work. Soon my books were covered with iron-rust, sleeper-tar and waggon grease, where my dirty hands had touched them, and when I had a book in my possession for a month I could hardly decipher a word on the pages. There is some difficulty in reading thus. I started to write verses of a kind, and one poem written by me was called The Lady of the Line. I personified the spirit that watched over the lives of railway men from behind the network of point-rods and hooded signals. The red danger lamp was her sign of power, and I wrote of her as queen of all the running lines in the world. I read the poem to my mates. Most of them liked it very much and a few learned it by heart. When Horse Roche heard of it he said: You'll end your days in the madhouse, or—with cynical repetition —in the House of Parliament. On Sunday afternoons, when not at work, I went to hear the socialist speakers who preached the true Christian Gospel to the people at the street corners. The workers seldom stopped to listen; they thought that the socialists spoke a lot of nonsense. The general impression was that socialists, like clergymen, were paid speakers; that they endeavoured to save men's bodies from disease and poverty as curates save souls from sin for a certain number of
- 54. shillings a day. From the first I looked upon socialist speakers as men who had an earnest desire for justice, and men who toiled bravely in the struggle for the regeneration of humanity. I always revolted against injustice, and hated all manner of oppression. My heart went out to the men, women, and children who toil in the dungeons and ditches of labour, grinding out their souls and bodies for meagre pittances. All around me were social injustices, affecting the very old and the very young as they affected the supple and strong. Social suffering begins at any age, and death is often its only remedy. That remedy is only for the individual; the general remedy is to be found in Socialism. Industry, that new Inquisition, has thousands on the rack of profit; Progress, to millions, means slavery and starvation; Progress and Profit mean sweated labour to railway men, and it meant death to many of them, as to Mick Deehan, whose place I had filled. I had suffered a lot myself: a brother of mine had died when he might have been saved by the rent which was paid to the landlord, and I had seen suffering all around me wherever I went; suffering due to injustice and tyranny of the wealthy class. When I heard the words spoken by the socialists at the street corner a fire of enthusiasm seized me, and I knew that the world was moving and that the men and women of the country were waking from the torpor of poverty, full of faith for a new cause. I joined the socialist party. For a while I kept in the background; the discussions which took place in their hall in G—— Street made me conscious of my own lack of knowledge on almost any subject. The members of the party discussed Spencer, Darwin, Huxley, Karl Marx, Ricardo, and Smith, men of whom I had never even heard, and inwardly I chafed at my own absolute ignorance and want of the education necessary for promoting the cause which I advocated. Hours upon hours did I spend wading through Marx's Capital, and Henry George's Progress and Poverty. The former, the more logical, appealed to me least. I had only been two months in the socialist party when I organised a strike among the railway men, the thirty members of the Flying
- 55. Squad on which I worked. We were loading ash waggons at C—— engine shed, and shovelling ashes is one of the worst jobs on the railway. Some men whom I have met consider work behind prison walls a pleasure when compared with it. As these men spoke from experience I did not doubt their words. The ash-pit at C—— was a miniature volcano. The red-hot cinders and burning ashes were piled together in a deep pit, the mouth of which barely reached the level of the railway track. The Flying Squad under Horse Roche cleared out the pit once every month. The ashes were shovelled into waggons placed on the rails alongside for that purpose. The men stripped to the trousers and shirt in the early morning, and braces were loosened to give the shoulders the ease in movement required for the long day's swinging of the shovel. Three men were placed at each waggon and ten waggons were filled by the squad at each spell of work. Every three wrought as hard as they were able, so that their particular waggon might be filled before the others. The men who lagged behind went down in the black book of the ganger. On the day of the strike the pit was a boiling hell. Chunks of coal half-burned and half-ablaze, lumps of molten slag, red-hot bricks and fiery ashes were muddled together in suffocating profusion. From the bottom of the pit a fierce impetus was required to land the contents of the shovel in the waggon overhead. Sometimes a brick would strike on the rim of the waggon and rebound back on the head of the man who threw it upwards. Cripes! we'll have to fill it ourselves now, his two mates would say as they bundled their bleeding fellow out of the reeking heat. A shower of fine ashes were continuously falling downwards and resting upon our necks and shoulders, and the ash-particles burned the flesh like thin red-hot wires. It was even worse when they went further down our backs, for then every move of the underclothing and every swing of the shoulders caused us intense agony. Under the run of the shirt the ashes scarred the flesh like sand-paper. All around a thick smoke rested and hid us from the world without, and within we suffered in
- 56. a pit of blasting fire. I've seen men dropping at the job like rats in a furnace. These were usually carried out, and a bucket of water was emptied on their face. When they recovered they entered into the pit again. Horse Roche stood on the coupling chains of the two middle waggons, timing the work with his watch and hastening it on with his curses. He was not a bad fellow at heart, but he could do nothing without flying into a fuming passion, which often was no deeper than his lips. Below him the smoke was so thick that he could hardly see his own labourers from the stand on the coupling chain. All he could see was the shovels of red ashes and shovels of black ashes rising up and over the haze that enveloped the pit beneath. But we could hear Roche where we wrought. Louder than the grinding of the ballast engine was the voice of the Horse cursing and swearing. His swearing was a gift, remarkable and irrepressible; it was natural to the man; it was the man. God's curse on you, Dan Devine, I don't see your shovel at work at all! he roared. Where the hell are you, Muck MaCrossan? Your waggon isn't nearly water-level yet, and that young whelp, Flynn, has his nearly full! If your chest was as broad as your belly, MacQueen, you'd be a danged sight better man on the ash-pile! It's not but that you are well enough used to the ashes, for I never yet saw a Heelin man who didn't spend the best part of his life before a fire or before grub! Come now, you men on the offside; you are slacking it like hell! If you haven't your waggon up over the lip, I'll sack every God-damned man of you on the next pay day! Has a brick fallen on Feeley's head? Well, shove the idiot out of the pit and get on with your work! His head is too big, anyhow, it's always in the road! This was the manner in which Horse Roche carried on, and most of the men were afraid of him. I felt frightened of the man, for I anticipated the gruelling which he would give me if I fell foul of him. But if we had come to blows he would not, I am certain, have much
- 57. to boast about at the conclusion of the affair. However, I never quarrelled with Roche. On the day of the strike, about three o'clock in the afternoon, when fully forespent at our work, the ballast engine brought in a rake of sixteen-ton waggons. Usually the waggons were small, just large enough to hold eight tons of ashes. The ones brought in now were very high, and it required the utmost strength of any one of us to throw a shovelful of ashes over the rim of the waggon. Not alone were the waggons higher, but the pile in the pit had decreased, and we had to work from a lower level. And those waggons could hold so much! They were like the grave, never satisfied, but ever wanting more, more. I suggested that we should stop work. Discontent was boiling hot, and the men scrambled out of the pit, telling Roche to go to hell, and get men to fill his waggons. Outside of the pit the men's anger cooled. They looked at one another for a while, feeling that they had done something that was sinful and wrong. To talk of stopping work in such a manner was blasphemy to most of them. Ronald MacQueen had a wife and a gathering of young children, and work was slack. Dan Devine was old, and had been in the service of the company for twenty years. If he left now he might not get another job. He rubbed the fine ashes out of his eyes, and looked at MacQueen. Both men had similar thoughts, and before the sweat was dry on their faces they turned back to the pit together. One by one the men followed them, until I was left alone on the outside. Horse Roche had never shifted his position on the coupling chains. It'll not pain my feet much, if I stand till you come back! he cried when we went out. He watched the men return with a look of cynical amusement. Come back, Flynn, he cried, when he saw me standing alone. You're a fool, and the rest of the men are cowards; their spines are like the spines of earth worms. I picked up my shovel angrily, and returned to my waggon. I was disgusted and disappointed and ashamed. I had lost in the fight, and I felt the futility of rising in opposition against the powers that
- 58. crushed us down. That night I sent a letter to the railway company stating our grievance. No one except myself would sign it, but all the men said that my letter was a real good one. It must have been too good. A few days later a clerk was sent from the head of the house to inform me that I would get sacked if I wrote another letter of the same kind. Then I realised that in the grip of the great industrial machine I was powerless; I was a mere spoke in the wheel of the car of progress, and would be taken out if I did not perform my functions there. The human spoke is useful as long as it behaves like a wooden one in the socket into which it is wedged. So long will the Industrial Carriage keep moving forward under the guidance of heavy- stomached Indolence and inflated Pride. There is no scarcity of spokes, human and wooden. What does it matter if Devine and MacQueen were thrown away? A million seeds are dropping in the forest, and all women are not divinely chaste. The young children are growing. Blessings be upon you, workmen, you have made spokes that will shove you from the sockets into which your feet are wedged, but God grant that the next spokes are not as wooden as yourselves! Again the road was calling to me. My search in Glasgow had been quite unsuccessful, and the dull slavery of the six-foot way began to pall on me. The clerk who was sent by the company to teach me manners was a most annoying little fellow, and full of the importance of his mission. I told him quietly to go to the devil, an advice which he did not relish, but which he forbore to censure. That evening I left the employ of the —— Railway Company. Just two hours before I lifted my lying time, the Horse was testing packed sleepers with his pick some distance away from the gang, when a rabbit ran across the railway. Horse dropped his pick, aimed a lump of slag at the animal and broke its leg. It limped off; we saw the Horse follow, and about a hundred paces from the point where he had first observed it Roche caught the rabbit, and proceeded to kill it outright by battering its head against the flange of the rail. At
- 59. that moment a train passed us, travelling on the down line. Roche was on the up line, but as the train passed him we saw a glint of something bright flashing between the engine and the man, and at the same moment Roche fell to his face on the four-foot way. We hurried towards him, and found our ganger vainly striving to rise with both arms caught in his entrails. The pick which he had left lying on the line got caught in the engine wheels and was carried forward, and violently hurled out when the engine came level with the ganger. It ripped his belly open, and he died about three minutes after we came to his assistance. The rabbit, although badly wounded, escaped to its hole. That night I was on the road again.
- 60. CHAPTER XXI A FISTIC ARGUMENT You're hungry and want me to give you food? I'll see you in hell first!—From Words to the Hungry. I left my job on Tuesday, and tramped about for the rest of the week foot-free and reckless. The nights were fine, and sleeping out of doors was a pleasure. On Saturday night I found myself in Burn's model lodging-house, Greenock. I paid for the night's bedding, and got the use of a frying-pan to cook a chop which I had bought earlier in the day. Although it was now midsummer a large number of men were seated around the hot-plate on the ground floor, where some weighty matter was under discussion. A man with two black eyes was carrying on a whole-hearted argument with a ragged tramp in one corner of the room. I proceeded to fry my trifle of meat, and was busily engaged on my job when I became aware of a disturbance near the door. A drunken man had come in, and his oaths were many, but it was impossible to tell what he was swearing at. All at once I turned round, for I heard a phrase that I knew full well. There's a good time comin', though we may never live to see it, said the drunken man. The speaker was Moleskin Joe, and face to face he recognised me immediately. Dermod Flynn, by God! he cried. Dermod—Flynn—by—God! How did you get on with your milkin', sonny? You're the only man I ever cheated out of five bob, and there's another man cheatin' you out of your bit of steak this very minute. I turned round rapidly to my frying-pan, and saw a man bending over it. This fellow, who was of middle age, and unkempt
- 61. appearance, had broken an egg over my chop, and was busily engaged in cooking both. I had never seen the man before. You're at the wrong frying-pan, I roared, knowing his trick. You're a damned liar, he answered. No, but you are the damned liar, I shouted in reply. Good! laughed Moleskin, sitting down on a bench, and biting a plug of tobacco. Good, Flynn! Put them up to Carroty Dan; he's worth keepin' your eye on. If he keeps his eye on me, he'll soon get it blackened, replied the man who was nick-named Carroty, on account of his red hair. This is my frying-pan. It is not, I replied. Had you an egg on this chop when you turned round? asked Carroty. I had not. Well, there's an egg on this pan, cully, so it can't be yours. I knew that it would be useless to argue with the man. I drew out with all my strength, and landed one on the jowl of Carroty Dan, and he went to the ground like a stuck pig. Good, Flynn! shouted Moleskin, spitting on the planking beneath his feet. You'll be a fighter some day. I turned to the chop and took no notice of my fallen enemy until I was also lying stretched amidst the sawdust on the floor, with a sound like the falling of many waters ringing in my head. Carroty had hit me under my ear while my attention was devoted to the chop. I scrambled to my feet but went to the ground again, having received a well-directed blow on my jaw. My mouth was bleeding now, but my mind was clear. My man stood waiting until I rose, but I
- 62. lay prone upon the ground considering how I might get at him easily. A dozen men had gathered round and were waiting the result of the quarrel, but Moleskin had dropped asleep on the bench. I rose to my knees and reaching forward I caught Carroty by the legs. With a strength of which, until then, I never thought myself capable, I lifted my man clean off his feet, and threw him head foremost over my shoulders to the ground behind. Knowing how to fall, he dropped limply to the ground, receiving little hurt, and almost as soon as I regained my balance, he was in front of me squaring out with fists in approved fashion. I took up a posture of instinctive defence and waited. My enemy struck out; I stooped to avoid the blow. He hit me, but not before I landed a welt on the soft of his belly. My punch was good, and he went down, making strange noises in his throat, and rubbing his guts with both hands. His last hit had closed my left eye, but all fight was out of Carroty; he would not face up again. The men returned to their discussion, Moleskin slid from his bench and lay on the floor, and I went on with my cooking. When Carroty recovered I gave him back his egg, and he ate it as if nothing had happened to disturb him. He asked for a bit of the chop, and I was so pleased with the thrashing I had given him that I divided half the meat with the man. Later in the evening somebody tramped on Moleskin Joe and awoke him. Who the hell thinks I'm a doormat? he growled on getting to his feet, and glowered round the room. No one answered. He went out with Carroty, and the two of them got as drunk as they could hold. I was in bed when they returned, and Carroty, full of a drunken man's courage, challenged me again to put them up to him. I pretended that I was asleep, and took no notice of his antics, until he dragged me out of the bed. Stark naked and mad with rage, I thrashed him until he shrieked for mercy. I pressed him under me, and when he could neither move hand nor foot, I told him where I was going to hit him, and kept him sometimes over two minutes waiting for the
- 63. blow. He was more than pleased when I gave him his freedom, and he never evinced any further desire to fight me. It's easy for anyone to thrash poor Carroty, said Joe, when I had finished the battle. On Sunday we got drunk together in a speak-easy[8] near the model, and it was with difficulty that we restrained Carroty from challenging everybody whom he met to fistic encounter. By nightfall Moleskin counted his money, and found that he had fourpence remaining. I'm off to Kinlochleven in the morning, he said. There's good graft and good pay for a man in Kinlochleven now. I'm sick of prokin' in the gutters here. Damn it all! who's goin' with me? I'm with you, gibbered Carroty, running his fingers through the blazing torch—the term used by Joe when speaking of the red hair of his mate. I'll go too, I said impulsively. I've only twopence left for the journey, though. Never mind that, said Moleskin absently. There's a good time comin'. Kinlochleven is situated in the wilderness of the Scottish Highlands, and I had often heard of the great job going on there, and in which thousands of navvies were employed. It was said that the pay was good and the work easy. That night I slept little, and when I slept my dreams were of the journey before me at dawn, and the new adventures which might be met with on the way.
- 64. FOOTNOTE: [8] A shebeen. You must speak easy in a shebeen when the police are around.
- 65. CHAPTER XXII THE OPEN ROAD The road runs north, the road runs south, and there foot- easy, slow, The tramp, God speed him! wanders forth, and nature's gentry go. Gentlemen knights of the gravelled way, who neither toil nor spin, Men who reck not whether or nay the landlord's rents come in, Men who are close to the natal sod, who know not sin nor shame, And Way of the World or Way of the Road, the end is much the same. —From A Song of the Road. In the morning I was afoot before any of my mates, full of impatience, and looking forward eagerly to the start. Wake up, Moleskin! I cried, as I bent over my mate, where he lay snoring loudly in the bed; it is time to be away. It's not time yet, for I'm still sleepy, said Moleskin drowsily. Slow and easy goes far in a day, he added, and fell asleep again. I turned my attention to Carroty. Get up, Carroty! I shouted. It's time that we were out on our journey.
- 66. What journey? grumbled Carroty, propping himself up on his elbow in the bed. To Kinlochleven, I reminded him. I never heard of it. You said that you would go this morning, I informed him. You said so last night when you were drunk. Well, if I said so, it must be so, said the red-haired one, and slipped out of the blankets. Moleskin rose also, and as a proof of the bond between us, we cooked our food in common on the hot-plate, and at ten minutes to ten by the town clock we set out on the long road leading to Kinlochleven. Our worldly wealth amounted to elevenpence, and the distance to which we had set our faces was every inch, as the road turned, of one hundred miles, or a six days' tramp according to the computation of my two mates. The pace of the road is not a sharp one. Slow and easy goes far in a day, is a saying amongst us, and it sums up the whole philosophy of the long journey. Besides our few pence, each man possessed a pipe, a knife, and a box for holding matches. The latter, being made of tin, was very useful for keeping the matches dry when the rain soaked the clothing. In addition, each man carried, tied to his belt, a tin can which would always come in handy for making tea, cooking eggs, or drinking water from a wayside well. When we got clear of the town Moleskin opened his shirt front and allowed the wind to play coolly against his hairy chest. Man alive! he exclaimed, this wind runs over a fellow's chest like the hands of a soncy wench! Then he spoke of our journey. Carroty was silent; he was a morbid fellow who had little to say, except when drunk, and as for myself I was busy with my thoughts, and eager to tramp on at a quicker pace. We'll separate here, and each must go alone and pick up what he can lay his hands on, said Moleskin. As I'm an old dog on the road,
- 67. far more knowing than a torch-headed boozer or young mongrel, I'll go ahead and lead the way. Whenever I manage to bum a bit of tucker from a house, I'll put a white cross on the gatepost; and both of you can try your luck after me at the same place. If you hear a hen making a noise in a bunch of brambles, just look about there and see if you can pick up an egg or two. It would be sort of natural for you, Carroty, to talk about your wife and young brats, when speaking to the woman of a house. You look miserable enough to have been married more than once. You're good lookin', Flynn; just put on your blarney to the young wenches and maybe they'll be good for the price of a drink for three. We'll sit for a bite at the Ferry Inn, and that is a good six miles of country from our feet. Without another word Joe slouched off, and Carroty and I sat down and waited until he turned the corner of the road, a mile further along. The moment he was out of sight, Carroty rose and trudged after him, his head bent well over his breast and his hands deep in the pockets of his coat. This slowness of movement disgusted me. I was afire to reach Kinlochleven, but my mates were in no great hurry. They placed their faith in getting there to-morrow, if to- morrow came. Each man was calmly content, when working out the problem of the day's existence, to allow the next day to do for itself. Carroty had barely turned the corner when I got up and followed. Over my head the sun burned and scalded with its scorching blaze. The grey road and its fine gravel, crunching under the heels of my boots, affected the ears, and put the teeth on edge. Far in front, whenever I raised my head, I could see the road winding in and out, now losing itself from my view, and again, further on, reappearing, desolate, grey, and lonely as ever. Although memories of the road are in a sense always pleasing to me, the road itself invariably depressed me; the monotony of the same everlasting stretch of dull gravelled earth gnawed at my soul. Most of us, men of the road, long for comfort, for love, for the smile of a woman, and the kiss of a child, but these things are denied to us. The women shun us as lepers are shunned, the brainless girl who works with a hoe in a
- 68. turnip field will have nothing to do with a tramp navvy. The children hide behind their mothers' petticoats when they see us coming, frightened to death of the awful navvy man who carries away naughty children, and never lets them back to their mothers again. He is a lonely man who wanders on the roads of a strange land, shunned and despised by all men, and foul in the eyes of all women. Rising cold in the morning from the shadow of the hedge where the bed of a night was found, he turns out on his journey and begs for a crumb. High noon sees nor wife nor mother prepare his mid-day meal, and there is no welcome for him at an open door when the evening comes. Christ had a mother who followed him all along the road to Calvary, but the poor tramp is seldom followed even by a mother's prayers along the road where he carries the cross of brotherly hate to the Valley of the Shadow of Death. Suddenly I saw a white cross on a gate in front of a little cottage. A girl stood by the door, and I asked for a slice of bread. From the inside of the house a woman cried out: Don't give that fellow anything to eat. We're sick of the likes of him. The maiden remonstrated. Poor thing! he must eat just like ourselves, she said. Once I heard one of the servant girls on Braxey Farm use the same words when feeding a pig. I did not wait for my slice of bread. I walked on; the girl called after me, but I never turned round to answer. And the little dignity that yet remained made me feel very miserable, for I felt that I was a man classed among swine, and that is a very bitter truth to learn at eighteen. Houses were rare in the country, but alas! rarer were the crosses of white. I had just been about two hours upon the journey, when as I was rounding a bend of the road I came upon Carroty sitting on a bank with his arms around a woman who sat beside him. I had been walking on the grass to ease my feet, and he failed to hear my approach. When he saw me, he looked half ashamed, and his
- 69. companion gazed at me with a look half cringing and half defiant. She put me in mind of Gourock Ellen. Her face might have been handsome at one time, but it was blotched and repugnant now. Vice had forestalled old age and left its traces on the woman's features. Her eyes were hard as steel and looked as if they had never been dimmed by tears. I wondered what Carroty could see in such a person, and it was poor enough comfort to know that there was at least one woman who looked with favour upon a tramp navvy. Tell Moleskin that I'm not comin' any further, Carroty shouted after me as I passed him by. All right, I answered over my shoulder. Afterwards I passed two white crosses, and at each I was refused even a crust of bread. Moleskin has got some, anyhow, and that is a comfort, I said to myself. Now I began to feel hungry, and kept an eye in advance for the Ferry Inn. Passing by a field which I could not see on account of the intervening hedgerow, I heard a voice crying Flynn! Flynn! in a deep whisper. I stopped and could hear some cows crop-cropping the grass in the field beyond. Flynn! cried the voice again. I looked through the hedgerow and there I saw Moleskin, the rascal, sitting on his hunkers under a cow and milking the animal into his little tin can. When he had his own can full I put mine through the branches and got it filled to the brim. Then my mate dragged himself through the branches and asked me where I had left Carroty. I told him about the woman. The damned whelp! I might have known, said Joe, but I did not know whether he referred to the woman or the man. We carried our milk cans for a little distance, then turning off the road we sat down in the corner of a field under a rugged tree and began our meagre meal. Joe had only one slice of bread. This he divided into equal shares, and when engaged in that work I asked him the meaning of the two white crosses by the roadside, the two crosses, which as far as I could see, had no beneficial results. They were all right, said Joe. I got food at the three places.
- 70. What happened to the other two slices? I asked. I gave it to a woman who was hungrier than myself, said Joe simply. We sat in a nice cosy place. Beside us rumbled a little stream; it glanced like anything as it ran over the stones and fine sands in its bed. From where we sat we could see it break in small ripples against the wild iris and green rushes on the bank. From above, the gold of the sunlight filtered through the waving leaves and played at hide and seek all over our muck-red moleskin trousers. Far down an osier bed covered the stream and hid it from our sight. From there a few birds flew swiftly and perched on the tree above our heads and began to examine us closely. Finding that we meant to do them no harm, and observing that Moleskin threw away little scraps which might be eatable, one bold little beggar came down, and with legs wide apart stood a short distance away and surveyed us narrowly. Soon it began to pick up the crumbs, and by-and-bye we had a score of strangers at our meal. Later we lay on our backs and smoked. 'Twas good to watch the blue of the sky outside the line of leaves that shaded us from the sun. The feeling of rest and ease was sublime. The birds consumed every crumb which had been thrown to them; then they flew away and left us. When our pipes were finished we washed our feet in the passing stream, and this gave us great relief. Moleskin pared a corn; I turned my socks inside out and hit down a nail which had come through the sole of my bluchers, using a stone for a hammer. Now we'll get along, Moleskin, I said, for I was in a hurry. Along be damned! cried my mate. I'm goin' to have my dog- sleep.[9] You have eaten, I said, and you do not need your dog-sleep to- day.
- 71. Joe refused to answer, and turning over on his side he closed his eyes. At the end of ten minutes (his dog-sleep usually lasted for that length of time), he rose to his feet, and walked towards the Clyde, the foreshore of which spread out from the lower corner of the field. A little distance out a yacht heaved on the waves, and a small boat lay on the shingle, within six feet of the water. The tide was full. Joe caught hold of the boat and proceeded to pull it towards the water, meanwhile roaring at me to give him a hand. This was a new adventure. I pulled with all my might, and in barely a minute's space of time the boat was afloat and we were inside of it. Joe rowed for all he was worth, and soon we were past the yacht and out in the deep sea. A man on the yacht called to us, but Joe put down one oar and made a gesture with his hand. The man became irate and vowed that he would send the police after us. My mate took no further heed of the man. Can you row? he asked me. I've never had an oar in my hand in my life, I said. How much money have you? he asked as he bent to his oars again. I gave all mine to that woman who was hungry. I have only a penny left, I said. We have to cross the Clyde somehow, said Joe, and a penny would not pay two men's fares on a ferry-boat. It is too far to walk to Glasgow, so this is the only thing to do. I saw the blokes leavin' this boat when we were at our grubbin'-up, so there was nothin' to be done but to take a dog-sleep until they were out of the way. My respect for Joe's cleverness rose immediately. He was a mate of whom anyone might have been proud. When once on the other side, we shoved the boat adrift; and went on the road again, outside the town of Dumbarton. Joe took the lead along the Lough Lomond road, and promised to wait for me when dusk was near at hand. The afternoon was very successful; I soon
- 72. had my pockets crammed with bread, and I got three pipefuls of tobacco from three several men when I asked for a chew from their plugs. An old lady gave me twopence and later I learned that she had given Moleskin a penny. Far outside of Dumbarton in a wild country, I overtook my mate again. It was now nearly nightfall, and the sun was hardly a hand's breadth above the horizon. Moleskin was singing to himself as I came up on him. I overheard one verse and this was the kind of it. It was a song which I had heard often before sung by navvies in the models. Oh! fare you well to the bricks and mortar! And fare you well to the hod and lime! For now I'm courtin' the ganger's daughter, And soon I'll lift my lyin' time. He finished off at that, as I came near, and I noticed a heavy bulge under his left oxter between the coat and waistcoat. It was something new; I asked him what it was, but he wouldn't tell me. The road ran through a rocky moor, but here and there clumps of hazel bounded our way. We could see at times soft-eyed curious Highland steers gazing out at us from amongst the bushes, as if they were surprised to see human beings in that deserted neighbourhood. When we stood and looked at them they snorted in contempt and crashed away from our sight through the copsewood. I think that we'll doss here for the night, said Moleskin when we had walked about a mile further. He crawled over a wayside dyke and threw down the bundle which he had up to that time concealed under his coat. It was a dead hen. The corpse of a hen, said Joe with a laugh. Now we've got to drum up, he went on, and get some supper before the dew falls. It is a hard job to light a fire when the night is on.
- 73. From experience I knew this to be the case; so together we broke rotten hazel twigs, collected some dry brambles from the undergrowth and built them in a heap. Joe placed some crisp moss under the pile; I applied a match and in a moment we had a brightly blazing fire. I emptied my pockets, proud to display the results of the afternoon's work, which, when totalled, consisted of four slices of bread, twopence, and about one half-ounce of tobacco. Joe produced some more bread, his penny, and three little packets which contained tea, sugar, and salt. These, he told me, he had procured from a young girl in a ploughman's cottage. But the hen, Moleskin—where did you get that? I asked, when I had gathered in some extra wood for the fire. On the king's highway, Flynn, he added with a touch of pardonable pride. Coaxed it near me with crumbs until I nabbed it. It made an awful fuss when I was wringing its neck, but no one turned up, more by good luck than anything else. I never caught any hen that made such a noise in all my life before. You are used to it then! I exclaimed. Of course I am, was the answer. When you are on the road as long as I've been on it, you'll be as big a belly-thief[10] as myself. It was fine to look around as the sun went down. Far west the sky was a dark red, the colour of old wine. A pale moon had stolen up the eastern sky, and it hung by its horn from the blue above us. Looking up at it, my thoughts turned to home, and I wondered what my own people would say if they saw me out here on the ghostly moor along with old Moleskin. I searched around for water, and found a little well with the moon at the bottom. As I bent closer the moon disappeared, and I could see the white sand beneath. I thought that the well was very holy, it looked so peaceful and calm out there alone in the wild place. I said to myself, Has anybody ever seen it before? What purpose does it serve here? I filled the billies, and when turning away I noticed that
- 74. a pair of eyes were gazing at me from the depths of the near thicket where a heavy darkness had settled. I felt a little bit frightened, and hurried towards the fire, and once there I looked back. A large roan steer came into the clearing and drank at the well. Another followed, and another. Their spreading horns glistened in the moonshine, and Joe and I watched them from where we sat. Will I take some more water here? I asked my mate, as he cleaned out the hen, using the contents of the second billy in the operation. Wait a minute till all the bullocks have drunk enough, he replied. It's a pity to drive them away. The fowl was cooked whole on the ashes, and we ate it with great relish. When the meal was finished, Moleskin flung away the bones. The skeleton of the feast, he remarked sadly. Next day was dry, and we got plenty of food, food enough and to spare, and we made much progress on the journey north. Joe had an argument with a ploughman. This was the way of it. Coming round a bend of the road we met a man with the wet clay of the newly turned earth heavy on his shoes. He was knock-kneed in the manner of ploughmen who place their feet against the slant of the furrows which they follow day by day. He was a decent man, and he told Moleskin as much when my mate asked him for a chew of tobacco. I dinna gang aboot lookin' for work and prayin' to God that I dinna get it, like you men, said the plougher. I'm a decent man, and I work hard and hae no reason to gang about beggin'. I was turning my wits upside down for a sarcastic answer, when Joe broke in. You're too damned decent! he answered. If you weren't, you'd give a man a plug of tobacco when he asks for it in a friendly way, you God-forsaken, thran-faced bell-wether, you!
- 75. If you did your work well and take a job when you get one, you'd have tobacco of your own, said the ploughman. Forbye you would have a hoose and a wife and a dinner ready for you when you went hame in the evenin'. As it is, you're daunderin' aboot like a lost flea, too lazy to leeve and too afeard to dee. By Christ! I wouldn't be in your shoes, anyway, Joe broke in quietly and soberly, a sign that he was aware of having encountered an enemy worthy of his steel. A man might as well expect an old sow to go up a tree backwards and whistle like a thrush, as expect decency from a nipple-noddled ninny-hammer like you. If you were a man like me, you would not be tied to a woman's apron strings all your life; you would be fit to take your turn and pay for it. Look at me! I'm not at the beck and call of any woman that takes a calf fancy for me. Who would take a fancy to you? You marry a wench and set up a beggarly house, said Joe, without taking any heed of the interruption. You work fourteen or fifteen hours a day for every day of the year. If you find the company of another woman pleasant you have your old crow to jaw at you from the chimney corner. You'll bring up a breed of children that will leave you when you need them most. Your wife will get old, her teeth will fall out, and her hair will get thin, until she becomes as bald as the sole of your foot. She'll get uglier until you loathe the sight of her, and find one day that you cannot kiss her for the love of God. But all the time you'll have to stay with her, growl at her, and nothin' before both of you but the grave or the workhouse. If you are as clever a cadger as me why do you suffer all this? Because I'm a decent man, said the plougher. Joe straightened up as if seriously insulted. Well, I'm damned! he muttered and continued on his journey. It's the first time ever I got the worst of an argument, Flynn, he said after we had gone out of the sight of the ploughman, and he kept repeating this phrase for
- 76. the rest of the day. For myself, I thought that Joe got the best of the argument, and I pointed out the merits of his sarcastic remarks and proved to him that if his opponent had not been a brainless man, he would be aware of defeat after the first exchange of sallies. But that about the decent man was one up for him, Joe interrupted. It was the only remark which the man was able to make, I said. The pig has its grunt, the bull its bellow, the cock its crow, and the plougher his boasted decency. To each his crow, grunt, boast, or bellow, and to all their ignorance. It is impossible to argue against ignorance, Moleskin. It is proof against sarcasm and satire and is blind to its own failings and the merits of clever men like you. Joe brightened perceptibly, and he walked along with elated stride. You're very clever, Flynn, he said. And you think I won? You certainly did. The last shot thrown at you struck the man who threw it full in the face. He admitted that he suffered because of his decency. Joe was now quite pleased with himself, and the rest of the day passed without any further adventure. On the day following it rained and rained. We tasted the dye of our caps as the water washed it down our faces into our mouths. By noon we came to the crest of a hill and looked into a wild sweep of valley below. The valley—it was Glencoe—from its centre had a reach of miles on either side, and standing on its rim we were mere midges perched on the copestones of an amphitheatre set apart for the play of giants. Far away, amongst grey boulders that burrowed into steep inclines, we could see a pigmy cottage sending a wreath of blue spectral smoke into the air. No other sign of human life could be seen. The cottage was subdued by its surroundings, the movement of the ascending smoke was a sacrilege against the spell of the desolate places.
- 77. It looks lonely, I said to my mate. As hell! he added, taking up the words as they fell from my tongue. We took our meal of bread and water on the ledge and saved up the crumbs for our supper. When night came we turned into a field that lay near the cottage, which we had seen from a distance earlier in the day. It's a god's charity to have a shut gate between us and the world, said Moleskin, as he fastened the bars of the fence. Some bullocks were resting under a hazel clump. These we chased away, and sat down on the spot which their bellies had warmed, and endeavoured to light our fire. From under grey rocks, and from the crevices in the stone dyke, we picked out light, dry twigs, and in the course of an hour we had a blazing flame, around which we dried our wet clothes. The clouds had cleared away and the moon came out silently from behind the shadow of the hills. The night was calm as the face of a sleeping girl. We lay down together when we had eaten our crumbs, but for a long while I kept awake. A wind, soft as the breath of a child, ruffled the bushes beside us and died away in a long-drawn swoon. Far in the distance I could hear another, for it was the night of many winds, beating against the bald peaks that thrust their pointed spires into the mystery of the heavens. From time to time I could hear the falling earth as it was loosened from its century-long resting place and flung heavily into the womb of some fathomless abyss. God was still busy with the work of creation! I was close to the earth, almost part of it, and the smell of the wet sod was heavy in my nostrils. It was the breath of the world, the world that was in the eternal throes of change all around me. Nature was restless and throbbing with movement; streams were gliding forward filled with a longing for unknown waters; winds were moving to and fro with the indecision of homeless wayfarers; leaves
- 78. were dropping from the brown branches, falling down the curves of the wind silently and slowly to the great earth that whispered out the secret of everlasting change. The hazel clump twined its trellises of branches overhead, leaving spaces at random for the eternal glory of the stars to filter through and rest on our faces. Joe, bearded and wrinkled, slept and dreamt perhaps of some night's heavy drinking and desperate fighting, or maybe his dreams were of some weary shift which had been laboured out in the lonely places of the world. Coming across the line of hills could be heard the gathering of the sea, and the chant of the deep waters that were for ever voicing their secrets to the throbbing shores. The fire burned down but I could not go to sleep. I looked in the dying embers, and saw pictures in the flames and the redness; pictures of men and women, and strange pictures of forlorn hopes and blasted expectations. I saw weary kinless outcasts wandering over deserted roads, shunned and accursed of all their kind. Also I saw women, old women, who dragged out a sordid existence, labouring like beasts of burden from the cradle to the grave. Also pictures of young women with the blood of early life in them, and the fulness of maiden promise in them, walking one by one in the streets of the midnight city—young women, fair and beautiful, who knew of an easier means of livelihood than that which is offered by learning the uses of sewing-needle or loom-spindle in fetid garret or steam-driven mill. In the flames and the redness I saw pictures of men and women who suffered; for in that, and that only, there is very little change through all the ages. Thinking thus I fell asleep. When I awoke, all the glory of the naked world was aflame with the early sun. The red mud of our moleskins blended in harmony with the tints of the great dawn. The bullocks were busy with their breakfasts and bore us no ill-will for the wrong which we had done them the night before. Two snails had crawled over Joe's coat, leaving a trail of slimy silver behind them, and a couple of beetles had found a resting-place in the seams of his velvet waistcoat. He rubbed his eyes when I called to him and sat up.
- 79. The snails curled up in mute protest on the ground, and the beetles hurried off and lost themselves amid the blades of grass. Joe made no effort to kill the insects. He lifted the snails off his coat and laid them down easily on the grass. Run, you little devils! he said with a laugh, as he looked at the scurrying beetles. You haven't got hold of me yet, mind. I never saw Joe kill an insect. He did not like to do so, he often told me. If we think evil of insects, what will they think of us? he said to me once. As for myself, I have never killed an insect knowingly in all my life. My house for so long has been the wide world, that I can afford to look leniently on all other inmates, animal or human. Four walls coffin the human sympathies. When I rose to my feet I felt stiff and sore, and there was nothing to eat for breakfast. My mate alluded to this when he said bitterly: I wish to God that I was a bullock! A crow was perched on a bush some distance away, its head a little to one side, and it kept eyeing us with a look of half quizzical contempt. When Joe saw it he jumped to his feet. A hooded crow! he exclaimed. I think that it is as well to start off, I said. We must try and pick up something for breakfast. My mate was still gazing at the tree, and he took no heed to my remark. A hooded crow! he repeated, and lifting a stone flung it at the bird. What about it? I asked. Them birds, they eat dead men, Moleskin answered, as the crow flew away. There was Muck Devaney—Red Muck we called him— and he worked at the Toward waterworks three winters ago. Red Muck had a temper like an Orangeman, and so had the ganger. The two of them had a row about some contract job, and Devaney lifted his lyin' time and jacked the graft altogether. There was a heavy
- 80. snow on the ground when he left our shack in the evenin', and no sooner were his heels out of sight than a blizzard came on. You know Toward Mountain, Flynn? Yes. Well, it is seven long miles from the top of the hill to the nearest town. Devaney never finished his journey. We found him when the thaw came on, and he was lyin' stiff as a bone in a heap of snow. And them hooded crows! There was dozens of them pickin' the flesh from his naked shoulder-blades. They had eat the very guts clean out of Red Muck, so we had to bury him as naked as a newborn baby. By God! Flynn, they're one of the things that I am afraid of in this world, them same hooded crows. Just think of it! maybe that one that I just threw the stone at was one of them as gobbled up the flesh of Muck Devaney. FOOTNOTES: [9] A sleep on an empty stomach in the full sun. [10] One who steals to satisfy his hunger.