All body cells rely on a constant supply of oxygen and nutrients and the ability to dispose of waste. The heart is the pump that supplies the body with blood, which is distributed around the body via a network of blood vessels. The heart contains four chambers: the right and left atria, and the right and left ventricles. The right atrium receives blood from the systemic circulation and passes it to the right ventricle. The blood then enters the pulmonary circulation to be loaded with oxygen from the lungs. Oxygen-rich blood returns in the left atrium and is pumped into the systemic circulation by the left ventricle. After supplying body cells in all organs (brain, liver, kidneys, muscles, intestine, and the heart itself), the blood returns once more to the right atrium.

This chapter discusses the following topics:


The blood supply to the muscles of the heart is provided by the


Sudden assumption of an upright position from supine position causes an initial decrease in: 


During diastole, a chamber of the heart


The amount of blood that is forced out of the heart depends on


What is true about microcirculation? 


Blood leaves the left ventricle by passing through the


Blood vessels that supply the walls of arteries and veins with blood are