Autonomic and Afferent Nerve Supply to Abdominal Viscera

Question 1

Which nerves provide parasympathetic stimulation to the abdominal viscera?

Answer 1

• vagus nerve (CN X)

- pelvic splanchnic nerves (S2-4)

Question 2

What does the vagus nerve supply?

Answer 2

supplies preganglionic parasympathetic fibers to the esophagus, stomach, small intestine, and large intestine through the right 2/3 of the transverse colon

Question 3

Which other abdominal viscera receive their parasympathetic innervation from the vagus?

Answer 3

• liver
• spleen
• pancreas
• kidney

Question 4

What do the pelvic splanchnic nerves supply?

Answer 4

supply preganglionic parasympathetic fibers to the left 1/3 of the transverse colon through the upper part of the anal canal

Question 5

Where do the preganglionic sympathetic fibers that are carried by the vagus and pelvic splanchnic nerves synapse?

Answer 5

in terminal gangli which lie within the organs they innervate

Question 6

Which nerves provide sympathetic stimulation to the abdominal viscera?

Answer 6

• sympathetic trunk

- splanchnic nerves

Question 7

Where are preganglionic sympathetic cell bodies located?

Answer 7

within spinal cord segments T1-L2

Question 8

Where is the sympathetic trunk located?

Answer 8

• enters the abdomen by passing posterior to the medial arcuate ligament
• descends on the vertebral column, medial to the psoas major muscle
• the right trunk lies behind the inferior vena cava
• the left trunk lies lateral to the aorta
• both trunks continue into the pelvis anterior to the sacrum

Question 9

Which nerves does the sympathetic trunk give rise to and from which spinal cord levels do they arise?

Answer 9

• thoracic and lumbar splanchnic nerves, which contain preganglionic sympathetic and afferent fibers
• arise from sympathetic trunk ganglia at the following levels:
  1. greater splanchnic nerve (T5-T9)
  2. lesser splanchnic nerve (T10-T11)
  3. least splanchnic nerve (T12)
  4. lumbar splanchnic nerve (L1-L4)

Question 10

Where does sympathetic innervation to the stomach through the right 2/3 of the colon originate? What nerves are they carried by?

Answer 10

• in the 5th-11th thoracic spinal cord segments
• the preganglionic fibers from these segments pass through the sympathetic trunk and are carried by the greater and lesser splanchnic nerves to the celiac and superior mesenteric plexuses, where they synapse

Question 11

Where does sympathetic innervation to the left 1/3 of the transverse colon through the upper part of the anal canal originate? What nerves are they carried by?

Answer 11

• in lumbar spinal cord segments
• the preganglionic fibers from these segments pass through the sympathetic trunk and are carried by the lumbar splanchnic nerves to the inferior mesenteric plexus

Question 12

Describe the celiac, superior mesenteric, and inferior mesenteric ganglia.

Answer 12

• contain the cell bodies of postganglionic sympathetic neurons
• the preganglionic sympathetic fibers carried by the splanchnic nerves synapse in these ganglia
• the postganglionic fibers travel from the ganglia to the organs they innervate via periarterial plexuses

Question 13

What is the afferent supply from the stomach to the middle of the sigmoid colon?

Answer 13

• fibers carrying pain sensation run with sympathetics to thoracic and lumbar spinal sensory ganglia
• visceral afferent fibers carrying reflex information run with the vagus to vagal sensory ganglia

Question 14

What is the afferent supply to the distal to the middle of the sigmoid colon?

Answer 14

both pain sensation and reflex information are carried to spinal sensory ganglia of S2-4

Question 15

Where do the various autonomic plexuses of the abdomen lie?

Answer 15

in front of the aorta and extend along its branches

Question 16

What do the autonomic plexuses contain?

Answer 16

• parasympathetic fibers
• sympathetic fibers
• afferent fibers
• autonomic ganglia

Question 17

What are the names of the autonomic plexuses?

Answer 17

• celiac plexus
• superior mesenteric plexus
• aortic plexus
• inferior mesenteric plexus

Question 18

What are the autonomic plexuses named after?

Answer 18

the arteries which they lie upon

Question 19

What are the autonomic plexuses divided into?

Answer 19

smaller plexuses

Question 20

What is the intermesenteric plexus?

Answer 20

the portion of the aortic plexus between the superior and inferior mesenteric arteries

Question 21

Describe the aortic plexus’ course.

Answer 21

continues downward to form the superior hypogastric plexus just below the bifurcation of the aorta