The surface of an alveolus in a mammal is well supplied with tiny blood vessels known as

The tiny blood vessels that are well supplied in the surface of an alveolus in a mammal are called capillaries. These vessels are extremely small, and they allow for the exchange of oxygen and carbon dioxide between the blood and the air in the lungs. This exchange is essential for breathing, as oxygen is needed to support the body's vital functions, and carbon dioxide is a waste product that needs to be removed. Capillaries are the smallest type of blood vessels in the body and are responsible for delivering oxygen and nutrients to the tissues while also removing waste products.