Downloaded 789 times
Uploaded byShweta Sharma
Anatomy and physiology of nervous system
The nervous system is made up of the central nervous system (brain and spinal cord) and the peripheral nervous system. The central nervous system contains approximately 10 million sensory neurons that send information to the brain and 500,000 motor neurons that control muscles and glands. The brain is protected by three layers of tissue called meninges and cerebrospinal fluid. The brain controls functions like sensation, memory, movement, vision, respiration, temperature regulation and more. The spinal cord transmits signals between the brain and body and contains sensory and motor neurons.
More Related Content
Similar to Anatomy and physiology of nervous system
![0001 Neurophysiology 0001[Recovered].ppt](https://cdn.slidesharecdn.com/ss_thumbnails/01neurophysiology0001recovered-250210163121-35929a9a-thumbnail.jpg?width=640&height=640&fit=bounds)
More from Shweta Sharma
Anatomy and physiology of nervous system
- 1. ANATOMY AND PHYSIOLOGY OF NERVOUSSYSTEM PRESENTED BY: MISS. SHWETA SHARMA M.SC. NURSING 2nd YEAR AIIMS JODHPUR
- 2. INTRODUCTION The nervous systemis a highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. 01-09-2020 2
- 3.
- 4.
- 5.
- 6. Cells of theNervous System 01-09-2020 6
- 7. The nervous systemhas approximately 10 million sensory neurons that send information about the internal and external environment to the brain and 500,000 motor neurons that control the muscles and glands. 01-09-2020 7
- 8.
- 9.
- 10.
- 11. • Ganglia areovoid structures containing cell bodies of neurons and glial cells supported by connective tissue. Ganglia function like relay stations - one nerve enters and an other exits. 01-09-2020 11
- 12.
- 13.
- 14.
- 15. ANATOMY OF THEBRAIN 01-09-2020 15
- 16.
- 17. The brain accountsfor approximately 2% of the total body weight; it weighs approximately 1,400 g in an average young adult. In the elderly, the average brain weighs approximately 1,200 g. 01-09-2020 17
- 18.
- 19.
- 20. •Information transferred includessensation, memory, and learned discrimination. •Right-handed people and some left-handed people have cerebral dominance on the left side of the brain for verbal, linguistic, arithmetical, calculating, and analytic functions. •The non-dominant hemisphere is responsible for geometric, spatial, visual pattern, and musical functions. 01-09-2020 20
- 21.
- 22.
- 23.
- 24.
- 25. The basal gangliaare masses of nuclei located deep in the cerebral hemispheres. 01-09-2020 25
- 26.
- 27.
- 28. The thalamus lieson either side of the third ventricle and acts primarily as a relay station for all sensation except smell. All memory, sensation, and pain impulses also pass through this section of the brain. 01-09-2020 28
- 29. •The hypothalamus islocated anterior and inferior to the thalamus. The hypothalamus lies immediately beneath and lateral to the lower portion of the wall of the third ventricle. 01-09-2020 29
- 30. •It includes theoptic chiasm (the point at which the two optic tracts cross) and the mamillary bodies (involved in olfactory reflexes and emotional response to odors). The infundibulum of the hypothalamus connects it to the posterior pituitary gland. 01-09-2020 30
- 31. •Plays an importantrole in the endocrine system because it regulates the pituitary secretion of hormones that influence metabolism, reproduction, stress response, and urine production. 01-09-2020 31
- 32. •Maintain fluid balance •Maintainstemperature regulation by promoting vasoconstriction or vasodilatation •Site of the hunger center and is involved in appetite control 01-09-2020 32
- 33. •Centers for regulatingthe sleep–wake cycle, blood pressure, aggressive and sexual behavior, and emotional responses (i.e., blushing, rage, depression, panic, and fear) •Controls and regulates the autonomic nervous system 01-09-2020 33
- 34.
- 35.
- 36.
- 37. •Nerve fibers fromall portions of the cortex converge in each hemisphere and exit in the form of a tight bundle of nerve fibers known as the internal capsule. •Having entered the pons and the medulla, each bundle crosses to the corresponding bundle from the opposite side.01-09-2020 37
- 38.
- 39.
- 40. •The midbrain connectsthe pons and the cerebellum with the cerebral hemispheres; it contains sensory and motor pathways and serves as the center for auditory and visual reflexes. Cranial nerves III and IV originate in the midbrain. 01-09-2020 40
- 41. •The pons issituated in front of the cerebellum between the midbrain and the medulla and is a bridge between the two halves of the cerebellum, and between the medulla and the cerebrum. Cranial nerves V to VIII connect to the brain in the pons. The pons contains motor and sensory pathways. Portions of the pons also control the heart, respiration, and blood pressure. 01-09-2020 41
- 42. • The medullaoblongata contains motor fibers from the brain to the spinal cord and sensory fibers from the spinal cord to the brain. Most of these fibers cross, or decussate, at this level. Cranial nerves IX through XII connect to the brain in the medulla. 01-09-2020 42
- 43.
- 44. •The cerebellum isseparated from the cerebral hemispheres by a fold of dura mater, the tentorium cerebelli. The cerebellum has both excitatory and inhibitory actions and is largely responsible for coordination of movement. It also controls fine movement, balance, position sense (awareness of where each part of the body is), and integration of sensory input. 01-09-2020 44
- 45.
- 46. Structures protecting thebrain The meninges (fibrous connective tissues that cover the brain and spinal cord) provide protection, support, and nourishment to the brain and spinal cord. 01-09-2020 46
- 47.
- 48.
- 49. Dura mater •It isthe outermost layer and covers the brain and the spinal cord. It is tough, thick, inelastic, fibrous, and gray. •There are four extensions of the dura: The falx cerebri, which separates the two hemispheres in a longitudinal plane. 01-09-2020 49
- 50. The tentorium, whichis an infolding of the dura that forms a tough membranous shelf. The falx cerebelli, which is between the two lateral lobes of the cerebellum. The diaphragm sellae, which provides a “roof” for the sella turcica. 01-09-2020 50
- 51. 01-09-2020 51 • Whenexcess pressure occurs in the cranial cavity, brain tissue may be compressed against the tentorium or displaced downward, a process called herniation.
- 52. • Arachnoid It isthe middle membrane; an extremely thin, delicate membrane that closely resembles a spider web (hence the name arachnoid). It appears white because it has no blood supply. The arachnoid layer contains the choroid plexus, which is responsible for the production of cerebrospinal fluid (CSF). 01-09-2020 52
- 53. •This membrane alsohas unique fingerlike projections, arachnoid villi, that absorb CSF. •In the normal adult, approximately 500 mL of CSF is produced each day but 125 to 150 mL is absorbed by the villi. 01-09-2020 53
- 54.
- 55. •When blood entersthe system (from trauma or haemorrhagic stroke), the villi become obstructed and hydrocephalus (increased size of ventricles) may result. •Pia mater—It is the innermost membrane; a thin, transparent layer that lies closely to brain and extends into every fold of the brain’s surface. 01-09-2020 55
- 56. Cerebrospinal fluid • Clearand colorless fluid with a specific gravity of 1.007 01-09-2020 56
- 57.
- 58. •The ventricular andsubarachnoid system contains approximately 125 to 150 mL of fluid, while 15 to 25 mL of CSF is located in each lateral ventricle. •The composition of CSF is similar to other extracellular fluids (such as blood plasma), but the concentrations of the various constituents are different. 01-09-2020 58
- 59. •The analysis andlaboratory report of CSF usually contains information on color, specific gravity, protein count, white blood cell count, glucose, and other electrolyte levels; it may also be tested for immunoglobulins or lactate. •Normal CSF contains a minimal number of white blood cells and no red blood cells. 01-09-2020 59
- 60. Cerebral circulation •The cerebralcirculation receives approximately 15% of the cardiac output. The brain does not store nutrients and has a high metabolic demand that requires the high blood flow. 01-09-2020 60
- 61. •In contrast toother organs that may tolerate decreases in blood flow because of their adequate collateral circulation, the brain lacks additional collateral blood flow, which may result in irreversible tissue damage when blood flow is occluded for even short periods of time. 01-09-2020 61
- 62.
- 63.
- 64. 01-09-2020 64 Cerebral veinsand sinuses are unique because, unlike other veins in the body, they do not have valves to prevent blood from flowing backward and depend on both gravity and blood pressure.
- 65. Blood–brain barrier • TheCNS is inaccessible to many substances that circulate in the blood plasma (e.g., dyes, medications, and antibiotics). After being injected into the blood, many substances cannot reach the neurons of the CNS because of the blood–brain barrier. This barrier is formed by the endothelial cells of the brain’s capillaries, which form continuous tight junctions, creating a barrier to macromolecules and many compounds. 01-09-2020 65
- 66. •All substances enteringthe CSF must filter through the capillary endothelial cells and astrocytes. Often altered by trauma, cerebral oedema, and cerebral hypoxemia, the blood–brain barrier has implications in the treatment and selection of medication for CNS disorders as well as serving a protective function. 01-09-2020 66
- 67.
- 68. • Brain wavesare rhythmic fluctuation of electric potential between parts of the brain as seen on an electroencephalo gram (EEG). To measure brain waves electrodes are placed onto the scalp using the EEG. 01-09-2020 68
- 69. Anatomy of thespinal cord •Approximately 45 cm (18 in) long and about the thickness of a finger, it extends from the foramen magnum at the base of the skull to the lower border of the first lumbar vertebra, where it tapers to a fibrous band called the conus medullaris. 01-09-2020 69
- 70. • Continuing belowthe second lumbar space are the nerve roots that extend beyond the conus, which are called the cauda equina because they resemble a horse’s tail. Similar to the brain, the spinal cord consists of gray and white matter. 01-09-2020 70
- 71.
- 72.
- 73.
- 74.
- 75.
- 76. 01-09-2020 76 The vertebrae areseparated by disks, except for the first and second cervical, the sacral, and the coccygeal vertebrae.
- 77. THE PERIPHERAL NERVOUS SYSTEM Theperipheral nervous system includes the cranial nerves, the spinal nerves, and the autonomic nervous system. 01-09-2020 77
- 78.
- 79. Three are entirely sensory (I,II, VIII), five are motor (III, IV, VI, XI, and XII), and four are mixed (V, VII, IX, and X) as they have both sensory and motor functions. 01-09-2020 79
- 80.
- 81. AUTONOMIC NERVOUS SYSTEM •Theautonomic nervous system regulates the activities of internal organs such as the heart, lungs, blood vessels, digestive organs, and glands. Maintenance and restoration of internal homeostasis is largely the responsibility of the autonomic nervous system. 01-09-2020 81
- 82.
- 83. •Sympathetic stimuli aremediated by nor-epinephrine and parasympathetic impulses are mediated by acetylcholine. •Sympathetic neurons are located in the thoracic and the lumbar segments of the spinal cord; their axons, or the pre- ganglionic fibers, emerge by way of anterior nerve roots from the eighth cervical or first thoracic segment to the second or third lumbar segment. 01-09-2020 83
- 84. Sympathetic Syndromes • Dilationof the pupil of the eye on the same side as a penetrating wound of the neck (evidence of disturbance of the cervical sympathetic cord) • Temporary paralysis of the bowel (indicated by the absence of peristaltic waves and the distention of the intestine by gas) after fracture of any one of the lower dorsal or upper lumbar vertebrae with hemorrhage into the base of the mesentery • Marked variations in pulse rate and rhythm that often follow compression fractures of the upper six thoracic vertebrae. 01-09-2020 84
- 85. MOTOR SYSTEM FUNCTION 01-09-202085 Cortical homunculus
- 86.
- 87.
- 88. •Coordination of Movement.The smoothness, accuracy, and strength that characterize the muscular movements of a normal person are attributable to the influence of the cerebellum and the basal ganglia. 01-09-2020 88
- 89. SENSORY SYSTEM FUNCTION IntegratingSensory Impulses •The thalamus integrates all sensory impulses except olfaction. It plays a role in the conscious awareness of pain and the recognition of variation in temperature and touch. The thalamus is responsible for the sense of movement and position and the ability to recognize the size, shape, and quality of objects.01-09-2020 89
- 90. Receiving Sensory Impulses •Afferentimpulses travel from their points of origin to their destinations in the cerebral cortex via the ascending pathways directly, or they may cross at the level of the spinal cord or in the medulla, depending on the type of sensation that is registered. Sensory information may be integrated at the level of the spinal cord or may be relayed to the brain. 01-09-2020 90
- 91. Sensory Losses • Destructionof a sensory nerve results in total loss of sensation in its area of distribution. Transection of the spinal cord yields complete anesthesia below the level of injury. Selective destruction or degeneration of the posterior columns of the spinal cord is responsible for a loss of position and vibratory sense in segments distal to the lesion, without loss of touch, pain, or temperature perception. 01-09-2020 91
- 92.
- 93. CONCLUSION • As discussedthroughout the presentation, learning about anatomy and physiology of brain and spinal cord will help nurses to understand the functioning of nervous system and various neurological disorders. • Nurses can do neurological assessment of patients, observe the sign and symptoms, provide the necessary nursing care, prevent any complications and support the patient psychologically.01-09-2020 93
- 94. REFERENCES 1.Janice L. Hinkle,Kerry H. Cheever. Brunner and Suddarth’s Textbook of Medical Surgical Nursing. 2015. New Delhi. Wolters Kluwer.13th Edition. Volume 1. Pg. no.1821-1834. 2.Lewis. Medical Surgical Nursing Assessment and Management of clinical problems.2015. New Delhi. Elsevier. 2nd Edition. Volume II. Pg. no.1391- 1400. 3.Joyce M. Black, Jane Hokanson Hawks. Medical Surgical Nursing Clinical Management of Positive Outcomes.2015. New Delhi. Reed Elsevier India Private Limited. Volume II. Pg. No. 1330-1331. 4.B D Chaurasia. HUMAN ANATOMY Regional and applied dissection and clinical. 2010. New Delhi. CBS Publishers. 5th edition. Volume 3. Pg. no. 315- 449. 01-09-2020 94
- 95.
- 96.