What is the function of arterioles?

What is the function of arterioles?

• A. Largest branches of arteries that carry blood away from the heart
• B. Smallest branches of an artery leading to the vast network of capillaries
• C. Vessels that transport blood to the heart
• D. Vessels that exchange gases in the lungs

Answer: (B)

Arterioles regulate blood flow into tissues by changing their diameter. They are the smallest branches of arteries, directly feeding the capillary networks that supply every tissue. The outer wall of arterioles contains smooth muscle that can constrict or relax in response to nervous system signals and local chemical cues. When they constrict, they increase resistance and reduce blood flow to a particular area; when they relax, they lower resistance and increase flow. This control helps distribute blood where it’s needed and helps set overall blood pressure. They’re not the largest arteries—that role belongs to larger arteries that carry blood away from the heart. They don’t transport blood to the heart—that’s the job of veins. Gas exchange occurs in the capillaries within the lungs and other tissues, not in the arterioles themselves, though arterioles are what deliver blood to those gas-exchanging capillaries.

Arterioles regulate blood flow into tissues by changing their diameter. They are the smallest branches of arteries, directly feeding the capillary networks that supply every tissue. The outer wall of arterioles contains smooth muscle that can constrict or relax in response to nervous system signals and local chemical cues. When they constrict, they increase resistance and reduce blood flow to a particular area; when they relax, they lower resistance and increase flow. This control helps distribute blood where it’s needed and helps set overall blood pressure.

They’re not the largest arteries—that role belongs to larger arteries that carry blood away from the heart. They don’t transport blood to the heart—that’s the job of veins. Gas exchange occurs in the capillaries within the lungs and other tissues, not in the arterioles themselves, though arterioles are what deliver blood to those gas-exchanging capillaries.