Question

The ________ brings about dilation of blood vessels?

• A. histamine
• B. gastrin
• C. elastin
• D. heparin

Hint:

Histamine is a key mediator of inflammation and is responsible for vasodilation, redness, and swelling at the site of injury.

Answer 1

The Correct Option is A

Step 1: Understanding the concept.
Dilation of blood vessels, also known as vasodilation, is a physiological response that increases blood flow to tissues. It commonly occurs during inflammation and allergic reactions.

Step 2: Analyzing the options.
(A) histamine: Histamine is released by mast cells during allergic and inflammatory responses. It causes vasodilation and increases the permeability of blood vessels.
(B) gastrin: Gastrin is a hormone that stimulates gastric acid secretion in the stomach and has no role in blood vessel dilation.
(C) elastin: Elastin is a structural protein found in connective tissues and does not actively cause vasodilation.
(D) heparin: Heparin is an anticoagulant that prevents blood clotting but does not cause vasodilation.

Step 3: Conclusion.
The correct answer is (A) histamine, as it directly causes dilation of blood vessels during inflammatory reactions.