What is the smallest kind of artery called?

The smallest kind of artery is known as an arteriole. Arterioles play a crucial role in the circulatory system as they regulate blood flow into the capillary beds, which are the sites of exchange between blood and tissues. These small arteries are primarily composed of smooth muscle, allowing for constriction and dilation, which helps control blood pressure and flow.

In contrast, capillaries are the smallest blood vessels but are not classified as arteries; they are the sites where oxygen and nutrients are exchanged for waste products. Venules are small vessels that carry blood away from capillaries and toward veins, while veins are larger vessels that carry deoxygenated blood back to the heart. Understanding the hierarchy and function of these blood vessels is foundational for comprehending how the circulatory system operates.