September 21, 2015 - Gut Sensation and Visceral Pain

Question 1

Referred Pain

Answer 1

Pain from organs may manifest as pain in a different location of the body because of the viscero-somatic convergence of the nerves.

For example, diaphragm pain may appear in the shoulder, while pancreas and gallbladder pain may go to the back.

Question 2

Visceral Hypersensitivity

Answer 2

Some people always feel pain in their gut. The visceral nerves are abnormally active.

This is often the cause in IBS.

Question 3

Drug Targets for Visceral Analgesia

Answer 3

There are multiple targets… The higher up the chain you go (going from the nerve to the brain), the more side effects you are going to have.

Question 4

5HT3 Antagonists

Answer 4

A class of drugs that act as receptor antagonists for the 5-HT₃ receptor, which is found in terminals of the vagus nerve.

Some members of this class can be used to treat irritable bowel syndrome (alosetron and cilansetron), while others are anti-emetics and are considered the gold standard for preventing vomitting in cancer patients undergoing chemotherapy.

Question 5

Afferent Pathway

Answer 5

Going to the brain.

Pain is only conveyed through the spinal afferent pathway.