PATHOLOGY

Detailed explanation-1: -Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins). The primary function of capillaries is the exchange of materials between the blood and tissue cells.

Detailed explanation-2: -The smallest of the arteries eventually branch into arterioles. They, in turn, branch into a extremely large number of the smallest diameter vessels-the capillaries (with an estimated 10 billion in the average human body). Next blood exits the capillaries and begins its return to the heart via the venules.

Detailed explanation-3: -The arterioles. The capillaries. The venules and veins returning blood to the heart.