Sympathetic Nervous System

Question 1

What is the function of the sympathetic nervous system? (5)

Answer 1

prepares the body for emergencies:

1) increase heartbeat
2) increase respiratory rate
3) increases blood pressure
4) suppresses the peristaltic movements of GI tract
5) constricts sphincters

Question 2

What is the sympathetic nervous system composed of? (3)

Answer 2

1) centers
2) ganglia
3) efferent fibers

Question 3

Where do the preganglionic neurons of the sympathetic nervous system reside?

Answer 3

lateral horn of the spinal cord segments T1-L2

Question 4

Where do preganglionic sympathetic neurons travel to?

Answer 4

travel along the ventral root of the spinal nerve and emerge through the intervertebral foramen

Question 5

White ramus communicans

Answer 5

what the preganglionic neurons of the sympathetic nervous system leave the spinal nerve as

Question 6

Where does the white ramus communicans enter?

Answer 6

sympathetic trunk

Question 7

What are the possible routes for the preganglionic sympathetic neurons? (4)

Answer 7

1) Synapse with postganglionic sympathetic neurons in the sympathetic trunk ganglia at the same level
2) Travel along sympathetic trunk and synapse with postganglionic sympathetic neurons in the sympathetic trunk ganglia at the different level
3) Bypass sympathetic trunk ganglia and form splanchnic nerves
4) Bypass sympathetic trunk ganglia and supply adrenal medulla

Question 8

What do the postganglionic sympathetic neurons (same level) provide? (2)

Answer 8

1) Return as gray ramus communicans at spinal nerve to target smooth muscles and glands of body wall skin
2) Travel to thoracic viscera to target cardiac and esophageal nerves

Question 9

Where do postganglionic fibers targeting the thoracic viscera arise from?

Answer 9

T1 to T4’s ganglion

Question 10

What do the postganglionic neurons (different level) provide? (2)

Answer 10

1) Enter spinal nerve as gray ramus communicans to distribute to upper and lower limb
2) Directly target head and neck viscera

Question 11

What do splanchnic nerves do?

Answer 11

Enter abdomen and synapse with postganglionic neurons in prevertebral ganglia (anterior to vertebral column)

Question 12

What do the postganglionic neurons (from splanchnic nerves) do? (2)

Answer 12

1) Target abdominal or pelvic viscera

2) Target pelvic viscera (sacral splanchnic nerves only)

Question 13

What are the postganglionic neurons for preganglionic neurons that supply the adrenal medulla?

Answer 13

adrenal medulla cells