The heart receives blood from the body via the superior and inferior vena cava. The heart has four valves - the tricuspid, mitral, pulmonary, and aortic. The main pace maker of the heart is the SA node. The impulse is carried to the AV node, the Bundle of His, and finally to the Purkinje Fibers causing the heart to contract. In between heats the heart is in a relaxed phase called diastole.
Contraction is called systole.
While listening to the heart two sounds are made as the valves close with contraction The first sound or S l is due to the AV valves closing and the second or S 2 is due to the closing of the pulmonary and aortic valves. The cardiac output per minute is equal to how fast the heart is beating and the amount or volume of blood that is pumped out of the heart with each beat. Arteries carry oxygenated blood to the capillaries where the oxygen is exchanged for carbon dioxide. The heart beat can be felt over the larger arteries. Arteries used to check the pulse are the carotid, brachial, radial, femoral, and popliteal Blood Pressure - Check blood pressure in both arms.