Intro To ANS

Question 1

Where are the cell bodies of presynaptic fibers of the sympathetic NS located?

Answer 1

In the lateral horn of the spinal cord

Short fibers

Question 2

Describe the route that presynaptic fibers of the sympathetic NS travel

Answer 2

Always travel in the anterior root —> into the anterior ramus —> quickly exit ramus and enter the paravertebral ganglia

Question 3

What are the synaptic options for presynaptic fibers of the sympathetic visceral distribution?

Answer 3

1. Enter the paravertebral ganglion and synapse onto a postsynaptic neuron in the same spinal level
2. Enter the paravertebral ganglion then ascend or descend to synapse on a postsynaptic neuron in a different spinal level
3. Enter the paravertebral ganglion and exit without synapsing and continue on through an abdominopelvic splanchnic nerve on their way to a post synaptic neuron in a prevertebral ganglion

Question 4

Where do cell bodies of sympathetic visceral distribution postsynaptic fibers exist?

Answer 4

In the paravertebral or prevertebral ganglia

Long fibers

Question 5

Describe sympathetic paravertebral ganglia of the visceral distribution?

Answer 5

Linked vertically to form sympathetic trunks on either idea of the vertebral column
Three ganglia also exist in the cervical, lumbar and pelvic regions

Question 6

Describe prevertebral ganglia of the sympathetic visceral distribution

Answer 6

Ganglia and corresponding plexuses surrounding the main unpaired branches of the abdominal aorta

Question 7

Describe the visceral distribution of the sympathetic NS

Answer 7

Innervation to visceral structures

Question 8

What is the parietal distribution of the sympathetic NS?

Answer 8

Innervation to smooth muscle of the skin and blood vessels as well as sweat glands

Question 9

Where do cell bodies of sympathetic parietal division postsynaptic fibers exist?

Answer 9

In the paravertebral ganglia

Question 10

Describe the route by which sympathetic parietal distribution post synaptic fibers exit the paravertebral ganglion?

Answer 10

Exit the paravertebral ganglion via gray rami communicans back into the somatic nerve

Question 11

For the sympathetic trunk distribution, presynaptic fibers enter the paravertebral ganglion and synapse onto what?

Answer 11

A postsynaptic neuron in the same spinal level

Question 12

For the sympathetic head, neck and UE distribution, presynaptic fibers enter the paravertebral ganglion at their own level and then do what?

Answer 12

Ascend to synapse on a postsynaptic neuron in the cervical sympathetic trunk

Question 13

For the sympathetic perineum and LE distribution, presynaptic fibers enter the paravertebral ganglion at their own level and then do what?

Answer 13

Descend to synapse on a postsynaptic neuron in the abdominal and sacral sympathetic trunk

Question 14

Gray ramus communicans allows for travel from what?

Answer 14

From the paravertebral ganglion back to the spinal nerve

Question 15

White ramus communicans allows for travel from what?

Answer 15

From the spinal nerve to the paravertebral ganglion

Question 16

Describe the route of sympathetic trunk postsynaptic fibers to the back

Answer 16

Postsynaptic fibers follow the posterior rami of the spinal nerves to innervate the smooth muscle and sweat glands of the back

Question 17

Describe the route of sympathetic trunk postsynaptic fibers to the get to the abdominal wall and lateral trunk

Answer 17

Postsynaptic fibers follow the anterior rami of the spinal nerves to innervate smooth muscle and sweat glands of the thoracic and abdominal body wall

Question 18

Describe the route of head, neck and UE sympathetic postsynaptic fibers travel to get to the head and face

Answer 18

Postsynaptic fibers follow carotid nerves and enter the carotid perarterial plexus to innervate smooth muscle and sweat glands of the head and face

Question 19

Describe the route of head, neck and UE sympathetic postsynaptic fibers travel to get to the posterior neck

Answer 19

Postsynaptic fibers follow the posterior rami of the spinal nerves (suboccipital, greater and least occ Ns) to innervate the smooth muscle and sweat glands of the posterior neck

Question 20

Describe the route of head, neck and UE sympathetic postsynaptic fibers travel to get to the anterior neck and US

Answer 20

Postsynaptic fibers follow the anterior rami of the spinal nerves which for the anterior neck make up the cervical plexus and for the UE make up the brachial plexus to innervate smooth muscle and sweat glands of the anterior neck and UE

Question 21

Describe the route of perineum and LE sympathetic postsynaptic fibers travel to get to the perineum and LE

Answer 21

Postsynaptic fibers follow the anterior rami of spinal nerves which make up the lumbar and sacral plexuses to innervate smooth muscle and sweat glands of the perineum and LE

Question 22

Describe the route of head, neck and UE sympathetic postsynaptic fibers travel to get to the buttocks

Answer 22

Postsynaptic fibers follow the posterior rami of the spinal cord nerves called cluneal nerves to innervate the smooth muscle and sweat glands of the buttocks

Question 23

Where are the nuclei of parasympathetic presynaptic fibers found?

Answer 23

In the brain stem and sacral spinal nerves

Question 24

Parasympathetic presynaptic fibers are what?

Answer 24

Long

Question 25

What are the two main components of parasympathetic presynaptic fibers?

Answer 25

Cranial component associated with CNs (III, VII, IX and X) and a sacral component that exits spinal levels as pelvic splanchnic nerves

Question 26

Describe parasympathetic postsynaptic fibers?

Answer 26

Usually short with ganglia/postsynaptic neurons near to in the target organ

Question 27

Where are the nuclei of parasympathetic postsynaptic fibers found?

Answer 27

In four specific cranial ganglia or in the wall of the target group

Question 28

What are intrinsic parasympathetic ganglia?

Answer 28

Postsynaptic parasympathetic cell bodies located in the walls of target organs

Question 29

How are the autonomic plexuses responsible for the innervation of structures innervated by the ANS?

Answer 29

They are usually made of mixed sympathetic and parasympathetic plexuses that travel on the vasculature to carry the postsynaptic (for the sympathetic) and presynaptic (for the parasympathetic division) to the target organs