Blood and Nerve Supply to Abdominal Organs

Question 1

When does the abdominal aorta begin? When does it terminate?

Answer 1

T12

L4

Question 2

Does the IVC lie to the right or left of the aorta?

What vein of the IVC crosses over aorta

Answer 2

Right

Left renal vein crosses anterior to the aorta

Question 3

What does the thoracic duct drain into?

Answer 3

left subclavian vein

Note: thoracic duct and cisterna chyli is to the right of aorta

Question 4

Where do abdominal aortic aneurysms usually arise? What is the primary cause?

Answer 4

Usually arises below the renal arteries and above the aortic bifurcation
Primarily due to atherosclerosis
(major complication is when >5cm)

Question 5

If the abdominal aorta is blocked between celiac trunk and SMA, what arteries will compensate?

Answer 5

Superior pancreaticoduodenal a inverior pancreaticoduodenal (SMA)

Question 6

What artery is within splenorenal ligament?

Answer 6

Splenic a.

Question 7

What does the portal vein drain?

Answer 7

Lower 1/3 of esophagus, stomach, small intestine, large intestine, and upper 1/2 of anal canal

Question 8

What forms the portal vein?

Answer 8

Union of splenic and superior mesenteric veins

Question 9

What is the liver drained by?

Answer 9

hepatic veins

Question 10

What must be ligated before removing the gallbladder?

Answer 10

Cystic a.

Question 11

What is calot’s node?

Answer 11

main rout of lymphatic drainage of gallbladder

Question 12

What is the route oft he superior mesenteric artery?

Answer 12

emerges from the aorta posterior to the neck of the pancreas, to the left of the SMV, enters THE mesentery and runs between its layers to reach the ileum and jejunum

Question 13

What does the right colic a supply?

Answer 13

ascending colon to right colic flexure

Question 14

What does the middle colic a supply?

Answer 14

right colic flexure and transverse colon

Question 15

What is the continuous anastomoses of the colon called?

Answer 15

marginal artery

Question 16

Where do the superior rectal vv drain to?

Answer 16

inferior mesenteric vein

Question 17

Where do the middle rectal vv drain to?

Answer 17

internal iliac veins

Question 18

Where do the inferior rectal vv drain to?

Answer 18

internal pudendal vv

Question 19

Describe sympathetic innervation in the abdomen

Answer 19

Preganglionic C fibers arise at T5-L1
travel in splanchnic nerves
synapse in prevertebral sympathetic ganglia
Postganglionic fibers travel to organs

Question 20

Describe the parasympathetic innervation in the abdomen

Answer 20

preganglionic fibers travel through celiac plexus but dont synapse
Synapse in enteric nervous system in gut wall
Vagus and pelvic nerves

Question 21

What does the vagus n innervate?

Answer 21

the foregut and midgut (stomach to prox 2/3 of transverse colon)

Question 22

What do the pelvic nn innervate?

Answer 22

(S2-S4) hindgut (all the way to prox rectum)

Question 23

What are the two principal components of the enteric nervous system?

Answer 23

myenteric (auerbach’s) plexus: between outer longitudinal and inner circular muscle layers; motility
Submucosal (meissner’s) plexus: secretions, blood flow, absorption

Question 24

Where do the sympathetic fibers from the greater, lesser and lowest splanchnic nerves synapse?

Answer 24

in the superior mesenteric ganglia

Question 25

What do the postganglionic fibers of the greater, lesser and lowest splanchnic nn follow?

Answer 25

branches of the superior mesenteric artery to target organs ‘

Question 26

What ligament is the short gastric a in?

Answer 26

gastrosplenic

poor anastamoses

Question 27

What is ischemic colitis?

Answer 27

Atherosclerosis, severe hypotension, blood clot or venous thrombosis, lupus or sickle cell and cocaine can cause irritation of the colon, decreased bowel sounds and abdominal tenderness
Tissue death -> perforation,or bowel obstruction

Question 28

What is hirschsprung disease?

Answer 28

failure of neural crest cells to migrate during intestinal development
No myenteric plexus
Neural crest cells become enteric ganglion cells
No parasympathetics = no relax, megacolon, constriction
rectosigmoid junction
Down syndrome babies have higher risk

Question 29

What parasites can cause megacolon?

Answer 29

T. cruzi
destroys autonomic nervous system
Mainly myenteric plexus