Question

multiple choice question
heparin is secreted by basophils. how does heparin help defend the body against infection?

• dilates blood vessels so that more blood can reach the injury
• poisons bacteria
• binds to foreign antigens so that they can be destroyed by phagocytes
• prevents clotting so immune cells can continue to reach the injury

Explanation:

Heparin is an anticoagulant. Its main function related to immune defense is to prevent blood clotting at the site of injury, which allows immune cells to keep moving to the injury area to fight infection. The option "Dilates blood vessels..." is more related to histamine (also from basophils), "Poisons bacteria" is not heparin's role, and "Binds to foreign antigens..." is for antibodies or other molecules, not heparin.

Answer:

D. Prevents clotting so immune cells can continue to reach the injury