Human anatomy and physiology-1st unit -4th topic- peripheral Nervous system
✿ Unit -4th✿
✯ PNS ✯
☆Nervous system☆
✷ Nervous system is the central control unit of the body which regulates and control the function of all organe of the body.
◍Classification of Nervous system;
1. Central nervous system.
(a.) Brain.
(b.) Spinal card.
2. Peripheral Nervous system.
(a.) Cranial nerve.
(b.) Spinal nerve.
3). Autonomic nervous system.
(a). Sympathetic
(b.) Parasympathetic.
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| Spinal cord structure |
◍Peripheral Nervous system;
✷ PNS includes all those nervous which arise from brain and spinal cord.
✷ Those nerve which arises from brain is called cranial nerve and which arises from spinal cord is called spinal nerve.
✷ All these nerves are connected with different organe and transfers the signals by releasing neurotransmitters.
◍ On the basis of nature these is of 3 types —
(a.) Sensory neuron ; Which transfer the signal organe to brain .
(b.) Motar neuron; Which send the information from brain to organe.
(c.) Mixed neuron; Which have both sensory & motar property.
☆Cranial nerve☆
✷ Those nerve which is arise from brain is called cranial nerve . In our body total 12 pairs of cranial nerve are found .
- Olfactory- sensory neuron - sense of smelling
- Optic - sensory ,, ,, - function of vision.
- Occulomotar - Motar ,, ,,- Raise upper eyelid,
- Trochlear - Motar ,, ,, - assisting in turning eyeball.
- Trigeminal- Mixed ,, ,, - chewing
- Abduces - Motar ,, ,,- movement of High.
- Facial- mixed ,,. ,, - Sense of taste , expression.
- Vestibuli cochlear- sensory ,, - sense of hearing
- Glassopharyngeal - Mixed,, ,, - movement of pharing
- Vagus- mixed,, ,, - secretion of organ movement
- Assesory- motar ,, ,,
- Hypoglosal - motar - movement of tongue.
☆Spinal nerve☆
✷ The 31 pairs of spinal nerves are present in human body which is arises from spinal cord.
✷ All spinal nerve are mixed in nature because in contain both sensory & motar axons .
◍ Spinal nerves are converted with 3 members—
(a.) Endoneurium
(b.) Perineurium
(c.) Epineurium
◍Distribution of spinal nerve ;
(1.) Cervical spinal nerve;
✷ 8 pairs
✷ 1st pair emerge between atlas and occipital bone.
✷ The remaining emerges from the vertebral column through foramen.
(2.) Thoracic spinal nerve;
✷ 12 pairs
✷ 1st pair emerge from vertebral column below the corresponding vertebrae emerge from thoracic vertebrae.
(3.) Lumber spinal nerve ;
✷ 5 pairs
✷ Emerge from lumber vertebra.
✷ Exist the vertebral column below the corresponding vertebra .
(4.) Sacral & coccyx spinal nerve;
✷ 5 pairs coccyx and 1 pair is sacral spinal nerve.
✷Emerge from the spinal cord , the root of sacral spinal nerve inter in sacral canal.
✷ Sacral nerve binds the vertebral column via 1 pair of anterior and posterior sacral foramen.
◍Physiology of spinal cord ;
✷ When we cut the T-S section of spinal nerve they we saw two type of matters—
1. White matter
2. Grey matter
✷ The white matter consists of cortex part and medulla is form grey matter.
✷ The grey matter of spinal cord three types of horn is present.
1. Dorsal horn
2. Lateral horn
3. Ventral horn
✷ Spinal cord promotes homeostasis by conducting nerve impulse along track.
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