PNS Autonomic Plexuses

Question 1

The autonomic plexuses are primarily concerned with supply of ______________ in the ___________ and ____________ cavities.

Answer 1

visceral structures
thoracic
abdominopelvic

Question 2

Fiber types include:

Answer 2

1. parasympathetic - preganglionic, postganglionic
2. sympathetic - preganglionic, postganglionic
3. afferents - somatic, visceral

Question 3

What is the main contribution to the esophageal plexus and where does the synapse occur?

Answer 3

main contribution is from vagus and recurrent laryngeal that synapse on postganglionic cells in wall of esophagus

Question 4

What is the sympathetic contribution to the esophageal plexus?

Answer 4

sympathetic contribution is from greater splanchnic nerves, arising from the T5-T9 ganglia

Question 5

What are the contributions to the thoracic aortic plexus?

Answer 5

1. vagus nerve (sensory, visceral afferent)
2. greater splanchnic nerve (sympathetic)
3. T1-T5 sympathetic ganglia (vascular)

Question 6

What is the primary component of the pulmonary plexus, how do they arrive at the plexus, and where does the synapse occur?

Answer 6

parasympathetics that arrive at the plexus via anterior and posterior bronchial branches of the vagus nerve. These preganglionic fibers synapse with postganglionic fibers in the wall of the bronchial vessels.

Question 7

What does parasympathetic stimulation of the pulmonary plexus result in?

Answer 7

• bronchiole constriction

- increased glandular activity

Question 8

Where do the sympathetic fibers that go to the pulmonary plexus come from and what do they supply?

Answer 8

sympathetic fibers to the pulmonary plexus are from T2-T4 ganglia. They supply the pleura, bronchial glands, and musculature.

Question 9

What does the cardiac plexus supply?

Answer 9

• myocardium
• great vessels at base of heart
• coronary arteries

Question 10

How do parasympathetic fibers reach the cardiac plexus and what does their stimulation result in?

Answer 10

Parasympathetic information arrives at the cardiac plexus via the superior and inferior cardiac nerves, branches of the vagus nerve. Their influence results in decreased heart rate and constriction of coronary arteries.

Question 11

How do sympathetic fibers reach the cardiac plexus and what does their stimulation result in?

Answer 11

Sympathetic fibers arrive from the superior, middle, and inferior cardiac nerve and from the T2-T4 sympathetic ganglia. Their influence results in increased heart rate and dilation of the coronary vessels.

Question 12

What is the largest prevertebral plexus?

Answer 12

celiac plexus

Question 13

What vertebral level does the celiac plexus begin at?

Answer 13

L1

Question 14

The celiac plexus is a dense gangliated plexus that forms a network around the __________________ and its branches down to and including the ___________ and ______________.

Answer 14

• abdominal aorta
• common iliac arteries
• median sacral arteries

Question 15

What are the three pairs of well-defined ganglia associated with the celiac plexus?

Answer 15

1. celiac ganglia, adjacent to celiac artery
2. superior mesenteric ganglia, associated with the superior mesenteric artery
3. aorticorenal ganglia, near renal arteries

Question 16

Secondary plexuses associated with the celiac plexus are named for the ________ associated with each one.

Answer 16

arteries

Question 17

What are the twelve secondary plexuses associated with the celiac plexus?

Answer 17

1. phrenic plexus (inferior phrenic artery)
2. left gastric plexus
3. hepatic plexus
4. splenic plexus
5. superior mesenteric plexus
6. suprarenal plexus (middle suprarenal artery)
7. renal plexus
8. gonadal plexus
9. abdominal aorta plexus
10. inferior mesenteric plexus
11. superior hypogastric plexus
12. inferior hypogastric plexus

Question 18

The superior hypogastric plexus is part of the celiac plexus between the ____ and _____ vertebral levels. It incudes the _________ and _________ plexuses.

Answer 18

• L4 and S1

- abdominal aortic and inferior mesenteric plexuses

Question 19

The inferior hypogastric plexus includes the celiac plexus below the __________________. It is the ______ largest prevertebral plexus.

Answer 19

• internal iliac artery

- second

Question 20

What four secondary plexuses is the inferior hypogastric plexus associated with?

Answer 20

1. vesicle
2. prostatic or uterine/vaginal
3. rectal
4. cavernous

Question 21

Defecation and micturition are initiated by _________ input.

Answer 21

parasympathetic

Question 22

What type of fibers are sensitive to stretching of walls of bladder or rectum and initiate a stretch reflex?

Answer 22

visceral afferents

Question 23

What type of fibers travel out to pelvic splanchnic nerves to detrusor muscle and/or rectal musculature?

Answer 23

efferents

Question 24

Efferent fibers travel out to pelvic splanchnic nerves to ___________ and/or ___________. External sphincter muscles are relaxed.

Answer 24

• detrusor muscle

- rectal musculature

Question 25

Efferent fibers travel out to pelvic splanchnic nerves to detrusor muscle and/or rectal musculature. ___________ muscles are relaxed.

Answer 25

external sphincter