1. ♠ Motor division issues directives out to muscle or glandular tissue
中枢/外周神经功能分类.
♠ Sensory division brings information regarding the int. or ext. environment into the CNS
♠ Motor division issues directives out to muscle or glandular tissue
♣Somatic nervous system services skeletal muscle
♣ Autonomic nervous system services smooth &cardiac muscle:
♦ Sympathetic nervous system is responsible for the "fight-or-flight"response;
♦ Parasympathetic nervous system is responsible for the "rest-anddigest"response

2. Divisions of the Nervous System
Central Nervous System
Peripheral Nervous System
nerves
cranial nerves
spinal nerves

3. The Spinal Nerves 1. General Description 31 Pairs of Spinal Nerves
Cervical Nerves : 8 pairs
Thoracic Nerves : 12 pairs
Lumbar Nerves : 5 pairs
Sacral Nerves : 5 pairs
Coccygeal Nerves : 1 pair

4. Four types of fibers in spinal Nerves
Two Roots : anterior root--motor fibers;
posterior root--sensory fibers
Somatic efferent[motor]fibers; Visceral efferent [motor] fibers
Four branches of a spinal nerves
Anterior branch ; posterior branch
Meningeal branch; communicating branches

5. Four plexuses
Cervical plexus颈丛
Brachial plexus臂丛
Lumbar plexus腰丛
Sacral plexus骶丛
The thoracic nerves are separated from each other.

7. Cervical Plexus
The cervical plexus is formed by ventral rami of
C1-C4
Most branches are cutaneous nerves of the neck, ear, back of head, and shoulders
The most important nerve of this plexus is the phrenic nerve
The phrenic nerve is the major motor and sensory nerve of the diaphragm

8. The cervical plexus is formed from ventral rami of the first 4 cervical nerves, buried deep in neck below the sternocleidomastoid muscle
Cervical plexus produces mostly cutaneous nerves serving skin of the ears,neck & shoulder
Also forms phrenic nerve serving the diaphragm

9. The cervical Plexus The Formation of the Cervical Plexus:
The anterior branches of the 1st to 4th cervical nerves (C1~4)

10. Brachial Plexus
Formed by C5-C8 and T1 (C4 and T2 may also contribute to this plexus)
It gives rise to the nerves that innervate the upper limb
Axillary – innervates the deltoid and teres minor
Median – branches to most of the flexor muscles of arm
Ulnar – supplies the flexor carpi ulnaris and part of the flexor digitorum profundus
Radial – innervates essentially all extensor muscles

11. The Brachial Plexus (scalene fissure, axilla)
formation: root(C5 – T1)

15. Radial Nerve

16. The Anterior Branches of the Thoracic Nerves ——Intercostal and subcostal nerve

17. The segmental distribution of the anterior branches of the thoracic nerves
T2: the sternal angle
T8: the costal arch
T4: the nipple
T10: the umbilicus
T6: the xiphoid process
T12: the anterior superior iliac spin

18. The Lumbar Plexus The formation of the lumbar plexus:
T12 (part)+L1~3+L4 (part)

19. The branches of the lumbar plexus
The iliohypogastric nerve
The ilioinguinal nerve
The lateral femoral
cutaneous nerve
The femoral nerve
The obturator nerve
The genitofemoral nerve

22. The Sacral Plexus The formation of the sacral plexus
The lumbosacral trunk(L4~5)+S1~5+Co

23. The branches of the sacral plexus The superior gluteal n.
The inferior gluteal n.
The pudendal n.
The posterior femoral
cutaneous n.
The sciatic nerve
The branches of the sacral plexus

24. The sciatic nerve The tibial nerve The common peroneal nerve
(Poplited fossa)
The tibial nerve
(hook-like foot)
The common peroneal
nerve
(talipes equinovarus)
The superficial peroneal
The deep peroneal nerve

27. Autonomic System Two divisions: Control involuntary functions
Sympathetic nerve交感神经
Parasympatheitic nerve副交感神经
Control involuntary functions
heartbeat
blood pressure
respiration
perspiration
digestion
Can be influenced by thought and emotion

28. Sympathetic “ Fight or flight” response
Release adrenaline and noradrenaline
Increases heart rate and blood pressure
Increases blood flow to skeletal muscles
Inhibits digestive functions
CENTRAL NERVOUS SYSTEM
Brain
Spinal
cord
SYMPATHETIC
Dilates pupil
Stimulates salivation
Relaxes bronchi
Accelerates heartbeat
Inhibits activity
Stimulates glucose
Secretion of adrenaline,
nonadrenaline
Relaxes bladder
Stimulates ejaculation
in male
Sympathetic
ganglia
Salivary
glands
Lungs
Heart
Stomach
Pancreas
Liver
Adrenal
gland
Kidney
keywords: sympathetic nervous system; fighlt or flight response

29. Parasympathetic “ Rest and digest ” system
Calms body to conserve and maintain energy
Lowers heartbeat, breathing rate, blood pressure
CENTRAL NERVOUS SYSTEM
Brain
PARASYMPATHETIC
Spinal
cord
Stimulates salivation
Constricts bronchi
Slows heartbeat
Stimulates activity
Contracts bladder
Stimulates erection
of sex organs
Stimulates gallbladder
Gallbladder
Contracts pupil
key words: parasympathetic nervous system; rest and digest system

30. Summary of autonomic differences
Autonomic nervous system controls physiological arousal
Sympathetic
division (arousing)
Parasympathetic
division (calming)
Pupils dilate EYES Pupils contract
Decreases SALVATION Increases
Perspires SKIN Dries
Increases RESPERATION Decreases
Accelerates HEART Slows
Inhibits DIGESTION Activates
Secrete stress
hormones
ADRENAL
GLANDS
Decrease secretion
of stress hormones
key words: sympathetic nervous system; parasympathetic nervous system

33. Sympathetic Division
Myelinated preganglionic exit spinal cord in ventral roots at T1 to L2[L3] levels.
Travel to ganglia at different levels to synapse with postganglionic neurons.
Divergence:
Preganglionic fibers branch to synapse with numerous postganglionic neurons.

34. Sympathetic Division
Axons of postganglionic neurons are unmyelinated to the effector organ.
Preganglionic neuron is short.
Post-ganglionic neuron is long.

35. Parasympathetic Division
Preganglionic fibers originate in midbrain, medulla, and pons; and in the 2-4 sacral levels of the spinal cord.
Preganglionic fibers synapse in ganglia located next to or within organs innervated.
Do not travel within spinal nerves.
Do not innervate blood vessels, sweat glands,and arrector pili muscles.

36. Parasympathetic Division
4 of 12 pairs of cranial nerves contain preganglionic parasympathetic fibers.
Preganglionic fibers are long, postganglionic fibers are short.
Vagus:
Innervate heart, lungs esophagus, stomach, pancreas, liver, small intestine and upper half of the large intestine.

37. Parasympathetic Division
Preganglionic fibers from the sacral level innervate the lower half of large intestine, the rectum, urinary and reproductive systems.