A capillary bed is a network of tiny blood vessels called capillaries that connect arterioles and venules. These capillaries are the smallest blood vessels in the body, allowing for the exchange of oxygen, nutrients, and waste products between blood and surrounding tissues. This exchange is crucial for maintaining healthy cellular function. Capillary beds are found throughout the body, including in organs like the lungs, muscles, and skin. The structure of capillaries, which have thin walls, facilitates the diffusion of substances. This network plays a vital role in regulating blood flow and ensuring that tissues receive adequate blood supply.