What structure forms a network of blood vessels between arterioles and venules?

The structure that forms a network of blood vessels between arterioles and venules is known as capillaries. Capillaries are the smallest blood vessels in the body and are crucial for the exchange of oxygen, carbon dioxide, nutrients, and waste products between the blood and surrounding tissues. This extensive network allows for efficient distribution of blood and facilitates the delivery of essential substances to cells as well as the removal of metabolic waste products.

In contrast, veins carry blood back to the heart, arteries transport blood away from the heart, and alveoli are tiny air sacs in the lungs involved in gas exchange rather than blood circulation. The unique structure of capillaries, with their single cell layer, enables them to perform their function effectively by allowing for the diffusion and exchange processes essential for maintaining homeostasis in the body.