Appendicular Skeleton....................

Appendicular
Skeleton
BY
Dr.V.S. Neharkar,M.Pharm,Ph.D
Dept. of Pharmacology,
RMDIPER,Chinchwad,Pune

APPENDICULAR SKELETON
The appendicular skeleton consists of :
•126 bones
•Allows us to move and manipulate objects
•Includes all bones besides axial skeleton
•The limbs
•The supportive girdles
•The Pectoral girdle with the upper limbs and the
Pelvic girdle with the lower limb.

The Pectoral Girdle
Also called the “shoulder girdle,” the pectoral girdle
contains four (4) bones. It functions to anchor and
support the upper extremities and serves as an important
attachment site for a great number of muscles that help
to move the arm.
The bones of the pectoral
girdle are as follows:
2 Clavicle ( Collar bone)
2 Scapula (Shoulder blade)

Clavicle
The clavicle is the only long bone that lies in a
horizontal position in the body. The clavicle has several
important functions. First, anchored by muscles from
above, it serves as a strut that extends laterally to support
the scapula.
This in turn holds
the shoulder joint
superiorly and
laterally from the
body trunk,
allowing for
maximal freedom
of motion for the
upper limb.

Scapula
Also known as the
“shoulder blades,” these contain
the shallow sockets into which
the head of the humerus fits.
The scapula lies on the
posterior aspect of the shoulder. It
is supported by the clavicle, which
also articulates with the humerus
(arm bone) to form the shoulder
joint.
The scapula is a flat,
triangular-shaped bone with a
prominent ridge running across its
posterior surface.

Bones of the Upper Limb
The upper extremities or
upper appendages, commonly
called the “arms,” contain a
total of sixty (60) bones from
regions commonly called the
“upper arm,” “forearm,”
“wrist,” and “hand.” The
bones of the upper extremities
are…
Humerus: 2
Radius: 2
Ulna: 2
Carpals: 16
Metacarpals: 10
Phalanges: 28

Humerus
This is the bone of the
upper arm. The head
articulates with the glenoid
cavity of the scapula, forming
the shoulder joint. Distal to the
head there are two roughened
projections of bone, the greater
and lesser tubercles, and
between them there is a deep
groove.
The bicipital groove
occupied by one of the tendons
of the biceps muscle.

Radius & Ulna
These are the two
bones of the forearm. The ulna
is longer than and medial to
the radius and when the arm
is in the anatomical position,
i.e. with the palm of the hand
facing forward, the two bones
are parallel.
They articulate with
the humerus at the elbow
joint, the carpal bones at the
wrist joint and with each other
at the proximal and distal
radioulnar joints.

There are eight carpal bones
arranged in two rows of four. From
outside inwards they are:
Carpal or wrist bones
5
1
2
3
4
4
3
2 1
6 5
7
8
Proximal row:
1 = Scaphoid
2 = Lunate
3 = Triangular
4 = Pisiform
Distal row:
5 = Trapezium
6 = Trapezoid
7 = Capitate
8 = Hamate

These bones are closely fitted together and held in
position by ligaments which allow a certain amount of
movement between them. The bones of the proximal row
are associated with the wrist joint and those of the distal
row form joints with the metacarpal bones.
Tendons of muscles lying in the forearm cross the
wrist and are held close to the bones by strong fibrous
bands.
Carpal or wrist bones

Metacarpal –
These five bones form the
palm of the hand. They are
numbered from the thumb side
inwards. The proximal ends
articulate with the carpal bones
and the distal ends with the
phalanges.
Phalanges-
There are 14 phalanges,
three in each finger and two in
the thumb. They articulate with
the metacarpal bones and with
each other.
Metacarpal bones & Phalanges

The Lower Limb
The lower extremities or lower
appendages, and commonly
called the “legs,” contain a
total of sixty (62) bones from
regions commonly called the
Pelvic girdle, “thigh,” “shin,”
“ankle,” and “foot.”.
 Pelvic Girdle
Coxal, innominate, or hip bones (2)
 Lower Extremity
Femur (2) Tibia (2)
Fibula (2) Patella (2)
Tarsals (14)
Metatarsals (10)
Phalanges (28)

The Pelvic Girdle
The pelvic girdle, also called the “pelvis,”
functions to support and protect the soft, vital organs
of the abdominal cavity, provide a stable support for
the trunk of the body, and to provide attachments for
the lower extremities (the legs). Each hip bone
consists of three fused bones these are-
a. The Ilium
b. The Ischium
c. The Pubis
a
b
c

The pelvic girdle (hip girdle) is formed by a single bone, the hip
bone or coxal bone (coxal = “hip”), which serves as the attachment
point for each lower limb. Each hip bone, in turn, is firmly joined to
the axial skeleton via its attachment to the sacrum of the vertebral
column. The right and left hip bones also converge anteriorly to
attach to each other. The bony pelvis is the entire structure formed by
the two hip bones, the sacrum, and, attached inferiorly to the sacrum,
& coccyx.
The hip bone, or coxal bone, forms the pelvic girdle portion of
the pelvis. The paired hip bones are the large, curved bones that form
the lateral and anterior aspects of the pelvis. Each adult hip bone is
formed by three separate bones that fuse together during the late
teenage years.
The Pelvic Girdle

The femur, or thigh
bone, is the single bone of the
thigh region It is the longest and
strongest bone of the body, and
accounts for approximately one-
quarter of a person’s total
height. The rounded, proximal
end is the head of the femur,
which articulates with the
acetabulum of the hip bone to
form the hip joint.
Femur

The patella (kneecap) is
largest sesamoid bone of the body
A sesamoid bone is a bone that is
incorporated into the tendon of a
muscle where that tendon crosses
a joint.
The sesamoid bone
articulates with the underlying
bones to prevent damage to the
muscle tendon due to rubbing
against the bones during
movements of the joint.
Patella

The tibia (shin bone) is the medial bone of the leg and is larger
than the fibula. The tibia is the main weight-bearing bone of the lower
leg and the second longest bone of the body, after the femur.
The medial side of the tibia is located immediately under the
skin, allowing it to be easily palpated down the entire length of the
medial leg. The distal extremity of the tibia forms the ankle joint with
the talus and the fibula. The medial malleolus is a downward
projection of bone medial to the ankle joint.
The fibula is the long slender lateral bone in the leg. The head
or upper extremity articulates with the lateral condyle of the tibia
forming the proximal tibiofibular joint and the lower extremity
articulates with the tibia to form distal tibiofibular joint.
Tibia and fibula

The posterior half of the foot is
formed by seven tarsal bones The most
superior bone is the talus. This has a
relatively square-shaped, upper surface
that articulates with the tibia and fibula
to form the ankle joint.
Tarsal Bones
1 = Calcaneus (heel bone)
2 = Talus (ankle bone)
3 = Navicular
4 = Medial Cuneiform
5 = Intermediate Cuneiform
6 = Lateral Cuneiform
7 = Cuboid
1 2 3
4
7
6
5
4
3
2
1
Medial 5 Lateral

The anterior half of the foot is formed by the five metatarsal
bones, which are located between the tarsal bones of the posterior
foot and the phalanges of the toes. These elongated bones are
numbered 1–5, starting with the medial side of the foot. At their
proximal ends they articulate with the tarsal bones and at their
distal ends, with the phalanges. The enlarged distal head of the 1st
metatarsal bone forms the 'ball' of the foot.
Metatarsal Bones

There are 14 phalanges
arranged in a similar manner
to those in the fingers, i.e.
two in the great toe and three
in each of the other toes.
Phalanges of the toes
1 2 3
4
7
6
5
4
3
2
1
Medial
Phalanges

The arrangement of the bones of the foot is such that
it is not a rigid structure. This point is well illustrated by
comparing a normal foot with a 'flat‘ foot. The bones have a
bridge-like arrangement and are supported by muscles and
ligaments so that four arches are formed, a medial and
lateral longitudinal arch and two transverse arches.
Arches of the foot

Appendicular Skeleton....................

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