The autonomic
nervous system
Xiaoming Zhang
The autonomic nervous system
• Introduction:
• Compositions:
1. Visceral sensory nerve
2. Visceral motor nerve
3. Centers of visceral nerves
• The visceral motor nerves:
2 parts: sympathetic and parasympathetic nerves
 The sympathetic nervous system:
1. lower center: in lateral horn of T1(or C8) ~ L3
segments of spinal cord
(intermediolateral nucleus)
2. peripheral part: sympathetic trunks
sympathetic ganglia
sympathetic plexuses
sympathetic nerves
communicating branches
 The sympathetic trunk:
--- paravertebral ganglia and interganglionic branches
--- extends from the base of skull to the coccyx
--- on the both sides of vertebral column
--- 5 parts: cervical part (superior, middle and inferior cervical
ganglia)
thoracic part (10~12 pairs of thoracic sympathetic
ganglia)
lumbar part (3~4 pairs of lumbar sympathetic ganglia)
sacral part (4~5 pairs of sacral sympathetic ganglia)
coccygeal part (1 unpair of coccygeal ganglion)
 The sympathetic ganglia: 2 types
---- paravertebral ganglia
---- prevertebral ganglia: celiac ganglia,
aorticorenal ganglia
superior mesenteric ganglia
inferior mesenteric ganglia
 The communicating branches:
--- link the sympathetic ganglion with the corresponding spinal
nerve.
---- 2 types: white and gray communicating branches
• white communicating branches
 sympathetic preganglionic fiberse
 arise from the neurons of lateral horn from T1~L3
segments of spinal nerves.
 about 15 pairs
 via the anterior roots of corresponding spinal nerves to
communicate with the paravertebral ganglia.
• gray communicating branches
 sympathetic postganglionic fiberse
 arise from the neurons of the paravertebral ganglia and
communicate with the 31 pairs of spinal nerves.

3 ways of termination of sympathetic preganglionic fibers
(the white communicating branches):
1. Some fibers terminate in the corresponding ganglion and make
relay.
2. Some fibers pass upward or downward in the sympathetic
trunk (form the interganglionic branches) to terminate in
above or lower paravertebral ganglia of the sympathetic trunk
and make relay.
3. The other fibers pass through sympathetic trunk to form some
splanchnic nerves and terminate in prevertebral ganglia.
---- greater splanchnic nerve
---- lesser splanchnic nerve

3 ways of termination of sympathetic preganglionic fibers
(the white communicating branches):
1. Some fibers terminate in the corresponding ganglion and make
relay.
2. Some fibers pass upward or downward in the sympathetic
trunk (form the interganglionic branches) to terminate in
above or lower paravertebral ganglia of the sympathetic trunk
and make relay.
3. The other fibers pass through sympathetic trunk to form some
splanchnic nerves and terminate in prevertebral ganglia.
---- greater splanchnic nerve
---- lesser splanchnic nerve

3 ways of termination of sympathetic preganglionic fibers
(the white communicating branches):
1. Some fibers terminate in the corresponding ganglion and make
relay.
2. Some fibers pass upward or downward in the sympathetic
trunk (form the interganglionic branches) to terminate in
above or lower paravertebral ganglia of the sympathetic trunk
and make relay.
3. The other fibers pass through sympathetic trunk to form some
splanchnic nerves and terminate in prevertebral ganglia.
---- greater splanchnic nerve
---- lesser splanchnic nerve
 3 ways of termination of sympathetic postganglionic fibers:
1. To form the gray communicating branches and run backward
to corresponding spinal nerve to peripheral blood vessels,
sweat glands and arrectores pilorum.
2. To surround the arteries as a layer of nerve plexus and
innervate the organs which supplied by the branches of
those arteries.
3. To terminate directly in certain organs by independent
sympathetic nerves.
 3 ways of termination of sympathetic postganglionic fibers:
1. To form the gray communicating branches and run backward
to corresponding spinal nerve to peripheral blood vessels,
sweat glands and arrectores pilorum.
2. To surround the arteries as a layer of nerve plexus and
innervate the organs which supplied by the branches of
those arteries.
3. To terminate directly in certain organs by independent
sympathetic nerves.
 3 ways of termination of sympathetic postganglionic fibers:
1. To form the gray communicating branches and run backward
to corresponding spinal nerve to peripheral blood vessels,
sweat glands and arrectores pilorum.
2. To surround the arteries as a layer of nerve plexus and
innervate the organs which supplied by the branches of
those arteries.
3. To terminate directly in certain organs by independent
sympathetic nerves.
 The parasympathetic nervous system:
1. Lower centers:
cranial portion---- 4 pairs of parasympathetic nuclei in
brain stem
sacral portion---- sacral parasympathetioc nucleus of
S2~4 segments of spinal cord
2. Peripheral part:
 cranial portion--- E-W nucleus----parasympathetic preganglionic fibers (via
oculomotor nerve)----ciliary ganglion (relay)---parasympathetic postganglionic fibers (short ciliary nerves)--- supply the ciliary m. and sphincter pupillae
 superior salivatory nucleus----parasympathetic preganglionic
fibers(via the facial nerve )----greater petrosal nerve----
pterygopalatine ganglion (relay)----parasympathetic
postganglionic fibers (via the maxillary—zygomatic – lacrimal
nerves)---- supply the lacrimal gland
 superior salivatory nucleus----parasympathetic preganglionic
fibers (via facial n.– chorda tympani – lingual n.)---submandibular ganglion(relay)----parasympathetic
postganglionic fibers----supply the submandibular and
sublingual glands
Inferior salivatory nucleus----parasympathetic preganglionic
fibers (via glossopharyngeal n.– tympanic n. – lesser petrosal n.)
---- otic ganglion (relay) ---- parasympathetic postganglionic
fibers(via auriculotemporal n.) ---- supply parotid gland
 dorsal nucleus of vagus n. ---- parasympathetic preganglionic
fibers (via the vagus n. and it’s branches) ---- ganglia in organs
(relay) ---- parasympathetic postganglionic fibers ---- supply the
organs of neck, thorax and abdomen (above the left colic flexure).
 The sacral portion of parasympathetic nervous system:
sacral parasympathetic nucleus ----parasympathetic
preganglionic fibers (via corresponding sacral nerves ---- 3
pelvic splanchnic nerves ---- pelvic plexus and it’s branches ) --ganglia in organs (relay) ---- supply the pelvic organs,
descending and sigmoid colons and rectum.
 The visceral sensory nerves:
 The sacral portion of parasympathetic nervous system:
sacral parasympathetic nucleus ----parasympathetic
preganglionic fibers (via corresponding sacral nerves ---- 3
pelvic splanchnic nerves ---- pelvic plexus and it’s branches ) --ganglia in organs (relay) ---- supply the pelvic organs,
descending and sigmoid colons and rectum.
 The visceral sensory nerves: