Final Exam GI Physiology: Large Intestine

Question 1

What are the 4 luminal secretions of the large intestine?

Answer 1

Mucin
HCO3- (exchanged for Cl-)
H+ (exchanged for Na+)
K+ (in response to aldosterone)

Question 2

What 2 paracrine substances does the large intestine secrete?

Answer 2

Histamine and prostaglandin (vasodilators)

Question 3

What is the 1 endocrine substance secreted by the large intestine?

Answer 3

GLP-1

Question 4

Na+ and Cl- are largely reabsorbed in the ___________ after having escaped reabsorption in the small intestine.

Answer 4

large intestine

Question 5

What 2 nerves are responsible for large intestine cholinergic and VIPergic stimulation?

Answer 5

Vagus n. and Pelvic n.

Question 6

Does the large intestine have luminal membrane Cl- secretory channels?

Answer 6

YES, it does, so it is NET reabsorptive

Question 7

Inflammation, histamine, toxins, and secretagogues promote the opening of _____ channels. As a result, the large intestine can become net secretory in the diseased state.

Answer 7

Cl- channels

Question 8

What is a clinical sign of a diseased state net secretory large intestine?

Answer 8

Large bowel secretory diarrhea

Question 9

The equine large intestine is the site of microbial fermentation and _____ production.

Answer 9

VFA production