What is the smallest type of blood vessel that connects arterioles and venules?

The smallest type of blood vessel that connects arterioles and venules is the capillary. Capillaries play a crucial role in the circulatory system by facilitating the exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues. They are characterized by their thin walls, generally composed of a single layer of endothelial cells, which allows for efficient diffusion of substances.

Arterioles are smaller branches of arteries, while venules are small vessels that drain blood from capillaries into larger veins. Neither arterioles nor venules can perform the specific function of connecting directly with both arterioles and venules the way capillaries do; capillaries serve as the critical interfaces where nutrient and gas exchange occurs, making them essential components of the vascular system.