Question

multiple choice question
histamine is secreted by basophils. what is the physiological role of histamine?

prevents clotting

isolates the antigens

binds to the foreign antigen

dilates blood vessels

Explanation:

To determine the physiological role of histamine secreted by basophils:

• "Prevents clotting" is a role of substances like heparin, not histamine.
• "Isolates the antigens" is not a primary role of histamine.
• "Binds to the foreign antigen" is done by antibodies, not histamine.
• Histamine is known to dilate blood vessels, especially during allergic reactions, to increase blood flow to the affected area.

Answer:

D. Dilates blood vessels