1. The Visceral Nervous System

2. The Visceral Nervous System
Composition
Visceral motor nerves (autonomic nervous system)
Sympathetic part 交感部
Parasympathetic part 副交感部
Visceral sensory nerves

3. Visceral motor nerves

5. Main differences between somatic motor and visceral motor n.
Effectors
Skeletal muscles
Cardiac, smooth muscles and glands
Kind of fibers
One
Two: sympathetic and parasympathetic
From lower center to effect require
Single neuron
Two neurons: preganglionic neuron (fiber) and postganglionic neuron (fiber)
Fibers
Thick myelinated
Preganglionic: thin myelinated
postganglionic: unmyelinated
Distributive form
Nerve trunk
Nerve plexuses
Control
Voluntary (consciousness)
Involuntary (unconsciousness )

6. Sympathetic part 交感部
Lower center: located in lateral gray horn of spinal cord segments T1~L3
Sympathetic ganglia
Paravertebral ganglia 椎旁节
Prevertebral ganglia 椎前节

7. Paravertebral ganglia 椎旁节
Arranged on either side of vertebral column
Consist of 19~22 of oval-shaped ganglia
Three cervical
10~12 thoracic
4 lumbar
2~3 sacral
Ganglion impar奇神经节: unpaired on the anterior face of coccyx

9. Sympathetic trunk 交感干
Formed by paravertebral ganglia and interganglionic branches
Lie on either side of vertebral column from base of skull to coccyx
The trunks of two side unite in front of the coccyx at a small swelling, the ganglion impar

10. Prevertebral ganglia 椎前节
Lie anterior to vertebral column and near the arteries for which they are named
Celiac ganglion 腹腔神经节
Aorticorenal ganglion 主动脉肾节
Superior mesenteric ganglion 肠系膜上神经节
Inferior mesenteric ganglion肠系膜下神经节

11. Three fates of preganglionic fibers
15 pairs white communicating branch
Preganglionic fibers
Sympathetic trunk
(only spinal levels T1~L3 have
white communicating branch)

12. Three fates of preganglionic fibers
Relay in corresponding ganglion
Ascend or descend in sympathetic trunk and relay in higher or lower ganglia
Pass without synapse to a prevertebral ganglion for relay

13. Greater splanchnic nerve 内脏大神经 formed by preganglionic fibers from T5~T9 ganglia, and relay in celiac ganglion.
Lesser splanchnic nerve 内脏小神经 formed by preganglionic fibers from T10~T12 ganglia, and relay in aorticorenal ganglion.
The postganglionic fibers supply the liver, spleen, kidney and alimentary tract as far as the left colic flexure.

14. Lumbar splanchnic nerve 腰内脏神经
Formed by preganglionic fibers from L1~L4 ganglia, and relay in prevertebral ganglia.
The postganglionic fibers supplydescending and sigmoid colon, rectum, pelvic viscera and lower limbs.

15. Three fates of postganglionic fibers
Back to a spinal nerve along gray communicating branches ( 31 pairs ) to terminate in blood vessels, arrectores pilorum and sweat glands of head, neck, trunk and limbs
The fibers from their networks around blood vessels passing to visceral end organs
Terminate directly in certain organs

16. Distribution of sympathetic nerve
Preganglionic fibers
Postganglionic fibers
T1~T5
Head, neck, upper limb and thoracic viscera
T5~T12
Abdominal viscera
L1~L3
Pelvic viscera and lower limb

17. Parasympathetic part 副交感部
Lower center: located in four pairs parasympathetic nuclei in brain stem and in sacral parasympathetic nucleus of spinal cord segments S2~S4
Parasympathetic ganglia: terminal ganglia are near or within the wall of a visceral organ
Para-organ ganglia 器官旁节：
Ciliary ganglion 睫状神经节
Pterygopalatine ganglion 翼腭神经节
Submandibular ganglion 下颌下神经节
Otic ganglion 耳神经节
Intramural ganglia 壁内节

18. Cranial portion颅部 Ⅲ sphincter pupillae and ciliary muscles
ciliary ganglion
lacrimal gland Ⅶ
pterygopalatine ganglion
sublingual gland
submandibular gland Ⅸ
submandibular ganglion Ⅹ
parotid gland
otic ganglion
heart, lungs, liver, spleen
kidneys,alimentary tract
as far as left colic flexure
terminal ganglia

19. Cranial portion颅部 Ⅲ
accessory oculomotor nucleus 〈○ sphincter pupillae and ciliary muscles
ciliary ganglion
pterygopalatine ganglion
Ⅶ 〈○ lacrimal gland
superior salivatory nucleus
〈○ sublingual gland
submandibular ganglion submandibular gland Ⅸ
inferior salivator nucleus 〈○ parotid gland
otic ganglion
Ⅹ heart, lungs, liver, spleen,
dorsal nucleus of vagus n 〈○ kidneys,alimentary tract
terminal ganglia as far as left colic flexure

20. Sacral portion 骶部
Preganglionic fibers from sacral parasympathetic nucleus leave spinal cord with anterior roots of the spinal nerves S2~S4,
Then leave sacral nerves and form pelvic splanchnic nerve and travel by way of pelvic plexus to terminal ganglia in pelvic cavity
Postganglionic fibers terminate in descending and sigmoid colon, rectum and pelvic viscera

22. Main differences between sympathetic and parasympathetic

23. Main differences between sympathetic and parasympathetic
Lower center
Lateral gray horn of spinal cord segments T1~L3
Four pairs parasympathetic nuclei and sacral parasympathetic nucleus
Ganglia
Paravertebral, prevertebral
Terminal
Preganglionic f.
Shorter
Longer
Postganglionic f.
Pre: Postganglionic
1: many more
1: a few
Distributions
Throughout the body
Limited primarily to head and viscera of thorax, abdomen, and pelvis
Different action
Prepares for emergency situation (fight or flight)
Conserve and restore body energy (rest and relaxation)

24. Visceral plexuses Cardiac plexuses Pulmonary plexus Celiac plexus
Superficial , below aortic arch
Deep, anterior to bifurcation on trachea
Pulmonary plexus
Celiac plexus
Abdominal aortic plexus
Hypogastric plexus
Superior hypogastric plexus
Inferior hypogastric plexus (pelvic plexus)

25. Visceral sensory nerves
Nucleus of solitary tract
Ⅶ，Ⅸ, Ⅹ
Thalamus
Cerebral
cortex
Enteroceptors
Hypothalamus
Posterior horn
Effectors
Sympathetic nerve
Pelvic splanchnic nerve
Somatic motor neurons
visceral motor neuclei

26. Referred pain 牵涉痛