Description: Veins carry blood to the heart. From the body via the inferior and superior
vena cava it is deoxygenated and from the lungs via the pulmonary vein it
is oxygenated.
Description: Capillaries have a width of a single red blood cell and connect arteries
and veins in tissues and organs. The capillary beds are where gas, oxygen,
and nutrient exchange occur between the blood and tissues.
