What are the smallest branches of arteries that lead to capillaries called?

Arterioles are indeed the smallest branches of arteries, and they play a critical role in the circulatory system as they lead directly to capillaries. These small blood vessels are essential for regulating blood flow and pressure within the vascular system.

Arterioles are muscular and can constrict or dilate, which allows them to control the amount of blood that enters into capillary networks. This regulation is vital for ensuring that different tissues receive appropriate amounts of blood and oxygen based on their metabolic needs. By managing this flow, arterioles help maintain blood pressure as well.

In contrast, venules are small vessels collecting blood from capillaries, capacitors is not a term used in this context, and veins are larger vessels that carry blood back to the heart. Understanding the structure and function of arterioles helps clarify their pivotal role in the transition from arteries to capillaries, where nutrient and gas exchange occurs.