8.3: Nerves of the abdomen

Question 1

which nerves innervate most of the muscles and skin of the anterolateral abdominal wall?

Answer 1

Lower intercostal nerves (T7–T11) and the subcostal nerve (T12) continue anteroinferiorly from their position on the thoracic wall to innervate most of the muscles and skin of the anterolateral abdominal wall.

Question 2

a somatic nerve plexus formed by the anterior rami of spinal nerves T12–L4, emerge from the psoas major muscle on the posterior abdominal wall

Answer 2

lumbar plexus. most nerves of this plexus innervate the lower limn.

Branches that innervate the abdominal wall and inguinal region:

iliohypogastric and ilioinguinal nerves (L1), which innervate the skin and muscles of the inferior anterior abdominal wall and the skin over the inguinal and pubic regions;

genitofemoral nerve (L1-L2), whose genital branch innervates the cremaster muscle surrounding the spermatic cord and the skin over the scrotum and labia; and

short muscular branches (T12–L4) that innervate the muscles of the posterior abdominal wall.

Question 3

8.22: nerves of the lumbar plexus

Answer 3

Question 4

Lumbar sympathetic trunks, the continuations of the sympathetic trunks in the thorax, descend along the lateral aspect of the lumbar vertebral bodies and give off three to four ___ ___ nerves, which join the autonomic plexuses of the abdomen.

Answer 4

Lumbar sympathetic trunks, the continuations of the sympathetic trunks in the thorax, descend along the lateral aspect of the lumbar vertebral bodies and give off three to four lumbar splanchnic nerves, which join the autonomic plexuses of the abdomen.

Question 5

which autonomic plexuses (preganglionic sympathetic nerves) do the thoracic splanchnic nerves contribute to? what about the lumbar splanchnic nerves?

Answer 5

thoracic splanchnic nerves (T5–T12), which contribute to the celiac, superior mesenteric and renal plexuses

lumbar splanchnic nerves (T11–L2), which contribute to the inferior mesenteric, superior hypogastric, and inferior hypogastric plexuses

Question 6

8.23: autonomic plexuses in the abdomen and pelvis. label

Question 7

REVIEW IMAGES

8. 24
9. 25
10. 26

Question 8

preganglionic parasympathetic nerves pass through the. plexuses and synapse in ganglia near their target organ. Which nerves do preganglionic parasympathetic nerves arise from?

Answer 8

the vagus nerves (cranial nerve X), which enter the abdomen as anterior and posterior vagal trunks from the esophageal plexus. They supply most of the abdominal viscera, including the digestive tract, except for its most distal segment (the descending colon to the anal canal). They contribute to all of the abdominal plexuses except the inferior mesenteric, superior hypogastric, and inferior hypogastric plexuses.

Or

the pelvic splanchnic nerves (S2–S4), which ascend from the pelvis to innervate the descending and sigmoid colons in the abdomen. They also innervate viscera of the pelvis. These fibers contribute to the inferior hypogastric plexuses.

Question 9

Although most abdominal plexuses contain both sympathetic and parasympathetic nerves, the ____ ____ and _____ ____ plexuses contain only sympathetic fibers.

Viscera supplied by these plexuses receive parasympathetic innervation via ____ ____nerves.

Answer 9

Although most abdominal plexuses contain both sympathetic and parasympathetic nerves, the inferior mesenteric and superior hypogastric plexuses contain only sympathetic fibers. Viscera supplied by these plexuses receive parasympathetic innervation via pelvic splanchnic nerves.

Question 10

subplexus and distribution of the celiac plexus/ganglia

Answer 10

Question 11

subplexus and distribution of the celiac of the superior mesenteric ganglia

Answer 11

no subplexxus, but has a large distribution:

Question 12

subplexus and distribution of the aorticorenal ganglion (suprerenal and renal plexus)

Answer 12

Question 13

subplexus and distribution of the inferior mesenteric plexus

Answer 13

Question 14

subplexus and distribution of the superior hypogastric plexus

Answer 14

the hypogastric nerves, supplying the pelvic viscera

Question 15

subplexus and distribution of the inferior hypogastric plexus

Answer 15

Question 16

NOTE: Table 8.9: effects of the autonomic nervous system in the abdomen and pelvis

Answer 16

Question 17

sympathetic fibers for the entire body originate from the thoracolumnbare region of the body in the lateral horns of spinal cord segments:

Answer 17

T1 through L2

Question 18

two-neuron sequence of the sympathetic moto system

Answer 18

1. presynaptic neurons have their cell bodies in teh lateral horns of the spinal grey matter (T1-L2)
2. post synaptic neuron cell bodies are located in prevertebral ganglia (celiac superior mesenteric, or inferior mesenteric ganglia) associated with midline branches of the abdominal aorta (celiac trunk, superior mesenteric artery, ingerior mesenteric artery)

Question 19

For the G1 system, presynaptic neuron acons enter the sympathetic chain but do not synapse. Instead, the presynaptic neurons continue to the ___ _____ ____ nerves to synpaase with post synaptic neurons.

Answer 19

For the G1 system, presynaptic neuron acons enter the sympathetic chain but do not synapse. Instead, the presynaptic neurons continue to the prevertebral ganglia splanchnic nerves to synpaase with post synaptic neurons.