Functional Anatomy of Gastrointestinal Tract

Question 1

*** What are the organs of alimentary canal?

Answer 1

oral cavity
pharynx
esophagus
small intestine
large intestine
stomach
rectum
anus

Question 2

*** What are the accessory organs of digestive system?

Answer 2

salivary glands
gallbladder
liver
pancreas

Question 3

Myenteric (Auerbach) Plexus

Answer 3

located in the middle of the muscular layer (between circular muscle and longitudinal muscle)

Question 4

Esophageal muscle types

Answer 4

upper 1/3 = striated muscle

middle 1/3 = striated & smooth muscles

lower 1/3 = smooth muscle

Question 5

Parietal (Oxyntic) Cells

Answer 5

secrete HCl & intrinsic factor (for absorption of vitamin B12)

Question 6

Enterochromaffin like cells

Answer 6

secrete histamine

Question 7

Chief (zymogen, peptic) cells

Answer 7

secrete pepsinogen

Question 8

G cells

Answer 8

secrete the hormone gastrin into the bloodstream

Question 9

*** An 18-year-old male with pernicious anemia lacks intrinsic factor, which is necessary for the absorption of cyanocobalamin. Vitamin B12 is absorbed primarily in which portion of the GI tract?

Answer 9

Ileum

Question 10

site of folate absorption

Answer 10

Jejunum

Question 11

site of vitamin B12 absorption

Answer 11

Ileum

Question 12

site of iron absorption

Answer 12

Duodenum

Question 13

Small intestine vs Large intestine functions

Answer 13

Small Intestine:
absorbs water, lipids, proteins, etc

Large Intestine:
absorbs water only

Question 14

Parasympathetic vs Sympathetic

Answer 14

P: activator
S: inducer

Question 15

MESENTERIC ISCHEMIA

Answer 15

Presenting features:

• “thumbprint sign”
• diffuse unremitting abdominal pain
• absent bowel sounds