GI GI Anatomy and Physiology 3

Question 1

The myenteric (Auerbach's) plexus lies between which two muscle layers of the GI tract?

Accepted Answer

Circular muscle and longitudinal muscle

Answer

Auerbach's plexus is located between the inner circular and outer longitudinal layers of the muscularis externa, controlling peristalsis.

Question 2

Which GI hormone inhibits gastric acid secretion and is released by D cells in the gastric antrum?

Accepted Answer

Somatostatin

Answer

Somatostatin from D cells inhibits gastrin and histamine release, thereby suppressing gastric acid secretion.

Question 3

The hepatic portal vein receives blood from all of the following EXCEPT:

Accepted Answer

Hepatic veins

Answer

Hepatic veins drain blood OUT of the liver into the inferior vena cava; they do not contribute to the portal vein.

Question 4

In the stomach, which cell type secretes pepsinogen, the precursor to the proteolytic enzyme pepsin?

Accepted Answer

Chief cells

Answer

Chief (zymogenic) cells in the gastric fundus and body secrete pepsinogen, which is activated to pepsin by acidic pH.

Question 5

Bile is stored and concentrated in the gallbladder, which can increase bile concentration by how much compared to hepatic bile?

Accepted Answer

10–20 fold

Answer

The gallbladder absorbs water and electrolytes, concentrating bile 10- to 20-fold relative to freshly secreted hepatic bile.

Gastrointestinal GI Practice Practice Test