Autonomic Nervous System

Front 1

What does the visceral motor system control?

Back 1

controls involuntary functions such as vascular tone and glandular secretions

Front 2

Name and describe 2 divisions of the visceral motor system

Back 2

Has two major divisions: sympathetic and parasympathetic  Both divisions consist of a two neuron chain.  The soma of the first neuron is located in the CNS.  The soma of the second neuron is located in a ganglia in the PNS.

Front 3

What carries pain information to the CNS?

Back 3

Visceral motor fibers (GVE) are accompanied by visceral afferent fibers (GVA). These fibers carry pain information to the CNS and also represent the afferent limb of autonomic reflexes; therefore, these fibers play an important role in the regulation of visceral functions.

Front 4

Where are the preganglionic sympathetic cell bodies located?

Back 4

Preganglionic sympathetic cell bodies are located in the lateral horn of the spinal cord (intermediolateral cell column) T1-L2/L3. Note the superiorinferior organization of the lateral horn.

Front 5

Preganglionic sympathetic fibers leave the spinal cord via the anterior horn of the spinal cord and do one of the following

Back 5

1. synapse in the sympathetic chain at the same level.
2. ascend or descend in the sympathetic chain/ paravertebral ganglia prior to synapsing at another level.
3. pass through the sympathetic chain without synapsing and
travel to prevertebral ganglia (eg. celiac, superior mesenteric, inferior mesenteric, aorticorenal)

Front 6

Where are the cell bodies of the postganglionic sympathetic fibers located?

Back 6

 Paravertebral ganglia (sympathetic chain/trunk)
 Prevertebral ganglia (celiac, superior mesenteric, inferior mesenteric ganglia, aorticorenal)

Front 7

Name the 3 cervical ganglia of the paravertebral ganglia

Back 7

• Superior cervical ganglion: located at
the C1- C2 vertebral level • Middle cervical ganglion: located at
the C6 vertebral level, cricoid cartilage • Inferior cervical ganglion: located at
the C7 vertebral level. In about 80% of individuals, this ganglion is fused with the first thoracic ganglion and is called the stellate ganglion

Front 8

1) # of thoracic ganglia?
2) # lumbar?
3) # sacral ganglia?

Back 8

1) 10-12
2) 4
3) 4-5

Front 9

1) Where don't the parasympathic fibers travel to?
2) How is this different from postganglionic sympathetic fibers?

Back 9

limbs or body wall
2) Postganglionic sympathetic fibers course in all spinal nerves and into most of the named nerves that course along the body wall and into the limbs (eg. intercostal nerves. These fibers course to blood vessels, sweat glands, arrector pili muscles

Front 10

What does the dental pulp receive?

Back 10

The dental pulp receives postganglionic sympathetic nerve fibers from the superior cervical ganglion (GVE). These fibers enter the root canal along with blood vessels.
 There may also be GV A fibers in the pulp that provide the CNS with information regarding the state of the vascular tone.
 Note the pulp also has pain fibers (GVA) that are carried along
with CN-V

Front 11

What does the superior cervical ganglion mainly recieve? Where does these fibers ascend?

Back 11

mainly receives preganglionic sympathetic fibers from T1 - T3 (few T4, T5) spinal cord levels. These fibers ascend through the sympathetic chain to reach the superior cervical ganglion, where they synapse.

Front 12

Postganglionic sympathic leave the superior cervical ganglion and form 5 things. Name these.

Back 12

1. form the internal carotid plexus and course along this artery to enter the cranial cavity. These fibers will be distributed with cranial nerves.
2. form the external carotid plexus and course along this artery into the face.
3. course to the carotid body and carotid sinus.
4. contribute to C1-C4 spinal nerves.
5. contribute to the cardiac plexus via Cardiopumonary
splanchnic n.

Front 13

What does the middle cervical ganglion recieve?
When the postganglionic sympathetic fibers leave this ganglion, what do they contribute to?

Back 13

Middle Cervical Ganglion
(smallest, occasionally absent). Mainly receives preganglionic sympathetic fibers from T1 - T3 (also T4, T5) spinal cord levels (not shown). Postganglionic sympathetic fibers leave this ganglion and contribute to:
1. C5 and C6 spinal nerves
2. cardiac plexus via
cardiopulmonary splanchnic nn.

Front 14

What does the inferior cervical ganglion receive? What do these fibers contribute to?

Back 14

Inferior Cervical Ganglion
(Stellate ganglion if fused with 1st thoracic ganglion). Mainly receives preganglionic sympathetic fibers from T1-T3 (also T4, T5) spinal cord levels. Postganglionic sympathetic fibers leave this ganglion and contribute to:
1. C7 and C8 spinal nerves
2. cardiac plexus via cardiopulmonary splanchnic nn.

Front 15

Where doe the preganglionic sympathic fibers from T1-T5 synapse? How about the postganglionic sympathetic fibers?

Back 15

In upper thoracic ganglia. Preganglionic sympathetic fibers from T1 -T5 spinal cord levels (lateral horn), [in addition to synapsing in superior, middle and inferior cervical ganglia (previous slides)], also synapse in thoracic paravertebral ganglia at the same level (T1 - T5)
Postganglionic sympathetic fibers leave the sympathetic chain and contribute to the cardiac and pulmonary plexuses via cardiopulmonary splanchnic nerves.

Front 16

What forms the (abdominopelvic) splanchnic nerves? what do they include?

Back 16

1) Preganglionic sympathetic fibers that pass through the sympathetic chain without synapsing form the (abdominopelvic) splanchnic nerves. Note: splanchinic refers to the fact that they go to organs
2) Include:
1. Greater splanchnic nerve (T5 -T9 spinal cord levels)
2. Lesser splanchnic nerve (T10-T11 spinal cord levels)
3. Least splanchnic nerve (T12 spinal cord level)
4. Lumbar splanchnic
nerves (L1- L2/3 spinal cord levels).

Front 17

Where do the abdominopelvic splanchnic nerves travel to? Where do the postganglionic sympathetic travel to?

Back 17

prevertebral ganglia.
*The prevertebral ganglia include the: celiac, aorticorenal, superior mesenteric and inferior mesenteric ganglia.
2) Postganglionic sympathetic
fibers leave one of the
above ganglia and are
distributed to abdominal
and some pelvic structures

Front 18

What might Horner Syndrome result from?

Back 18

may result from interruption in the cervical sympathetic chain and result in the absence of sympathetically stimulated functions on the ipsilateral side of the head.
• pupil constriction
• ptosis: drooping superior eyelid
• redness of skin (vasodilation)
• anhydrosis: absence of sweating17

Front 19

What might lesions of cervical sympathetic chain result in?

Back 19

Thyroid carcinoma, thyroid surgery, neoplastic lesions, local trauma, surgical extirpation

Front 20

What might lesions of spinal root at T1 result in?

Back 20

apical carcinoma of the lung, cervical ribs, aortic aneruysms, avulsion of the lower plexus

Front 21

Parasympathetic nervous system
Describe location of the pre, post-ganglionic cell bodies.

Back 21

 The cell body of preganglionic parasympathetic fibers are located in brainstem nuclei associated with CN- III, VII, IX, X.
 The cell body of postganglionic parasympathetic fibers are located in a ganglia close
to the target organ (we will discuss this in detail with the cranial nerve lectures in module
IV)
 The cell body of
preganglionic
parasympathetic fibers are
also located in S2, S3, S4