AP BIOLOGY

Detailed explanation-1: -There are three types of blood vessels: Arteries carry blood away from your heart. Veins carry blood back toward your heart. Capillaries, the smallest blood vessels, connect arteries and veins.

Detailed explanation-2: -This vast system of blood vessels-arteries, veins, and capillaries-is over 60, 000 miles long. That’s long enough to go around the world more than twice! Blood flows continuously through your body’s blood vessels.

Detailed explanation-3: -With the exception of pulmonary blood vessels, arteries carry oxygenated blood and veins carry deoxygenated blood. Arteries have thick walls with muscle tissue. Veins have thinner walls and use valves to keep your blood flowing.

Detailed explanation-4: -The great vessels of the heart include your aorta, pulmonary trunk, pulmonary veins and vena cava (superior and inferior).

Detailed explanation-5: -Blood vessels contain only smooth muscle cells. These muscle cells reside within the tunica media along with elastic fibers and connective tissue.