What term describes the tiny network of blood vessels throughout the body?

The term that describes the tiny network of blood vessels throughout the body is capillaries. Capillaries are the smallest blood vessels, connecting the arterioles (which carry blood away from the heart) and venules (which return blood to the heart). Their thin walls allow for the exchange of oxygen, carbon dioxide, nutrients, and waste products between blood and the tissues. This crucial function of capillaries plays a significant role in the body's circulatory system, facilitating the delivery of vital substances to cells and the removal of byproducts.

Unlike arteries and veins, which are larger vessels responsible for distributing blood to and from the heart, capillaries specifically serve as the sites of exchange. Arterioles, while also part of the arterial system, lead directly into capillary networks but do not represent the small-scale network themselves. Therefore, understanding the role and structure of capillaries is essential for recognizing how blood circulation and nutrient exchange are effectively managed within the body.