Every patient should be monitored for the signs and symptoms of shock. The heart functions as the human circulatory system s pump. The heart consists of four separate chambers, two on top and two on the bottom. The ventricles are the larger of the two and do most of the actual pumping. The atria are somewhat less muscular and serve more as a reservoir for blood flowing into and out of the heart.
Capillaries form a network that distributes blood to all parts of the body.
At its point of smallest diameter, a capillary is so narrow that blood cells have to flow single file. The veins return the blood from the capillaries to the heart, where it is pumped to the lungs. There, the blood gives off carbon dioxide and takes on oxygen. Fluid consists of blood cells and other blood components, each with a specific function. The liquid part of the blood is known as plasma.