GI Lecture 44 & 45

Question 1

Major physiological processes of GI Tract (4)

Answer 1

• Motility
• Secretion
• Digestion
• Absorption

Question 2

Celiac artery profuses?

Answer 2

• liver
• spleen
• stomach

Question 3

Superior Mesenteric Artery (SMA) profuses?

Answer 3

• pancreas
• small intestine
• proximal colon

Question 4

Inferior Mesenteric Artery (IMA) profuses?

Answer 4

-distal colon

Question 5

Layers of the Gut wall

Answer 5

• Mucosa
• Submucosa
• Muscalaris externa
• Serosa

Question 6

Layers of Mucosa

Answer 6

• Epithelium
• the lamina propria
• muscularis mucosae

Question 7

Absorptive enterocytes

Answer 7

-play vital role in digestion and absorption

Question 8

Enteroendocrine cells

Answer 8

• releases regulatory peptides & amines to regulate GI function
• sensor cell

Question 9

Gastric Mucosal cells

Answer 9

produce protons

Question 10

Where can you find the submucosal plexus (Meissner’s plexus)?

Answer 10

submucosa (located just underneath mucosal layer)

Question 11

Where can you find the myenteric plexus?

Answer 11

In muscularis externa between the inner circular muscle layer and the outer longitudinal muscle layer

Question 12

Function of Serosa

Answer 12

lubricate/protect organ

Question 13

Histamine

Answer 13

• paracrine
• released by ECL in stomach, diffuses through the interstitial space and binds to neighboring parietal cells that secrete HCL

Question 14

Serotonin

Answer 14

• Paracrine
• regulate contractile activity of smooth muscle cells in GI system
• released from enteric neurons, mucosal mast cells, special EECs

Question 15

Cholecystokinin

Answer 15

• Paracrine and Endocrine
• acts locally on nerve terminals
• travels to pancreas
• released from duodenum
• CCK1

Question 16

What innervates the upper one-third of the esophagus?

Answer 16

Cranial nerve VII & IX

Question 17

Where do the pelvic nerves innervate?

Answer 17

The distal part of the colon and anorectal region