How Does a Normal Heart Work?

The human heart is a complex organ, often beating unheard but accomplishing life-sustaining functions every minute of our life. This muscle, about the size of a fist, is made up of four chambers and four valves. The right atrium and the left atrium are the two top chambers of the heart. The right ventricle and left ventricle are the two bottom chambers of the heart. The four heart valves are the tricuspid valve, mitral valve, pulmonary valve, and aortic valve. The tricuspid valve is located between the right atrium and the right ventricle. The mitral valve is located between the left atrium and the left ventricle. The pulmonary valve is located between the right ventricle and the pulmonary artery, the blood vessel that delivers oxygen-poor blood to the lungs. The aortic valve is located between the left ventricle to the aorta, the large blood vessel that delivers oxygen-rich blood to the body.


Healthy Heart Structure


Blood delivers oxygen to all the different organs in the body and then the oxygen-poor blood returns to the heart through two large blood vessels connected directly to the heart. These two blood vessels connect to the right atrium, the upper right heart chamber. The oxygen-poor blood travels through the tricuspid valve then to the right ventricle, which pumps the blood into the lungs through the pulmonary valve and into the main pulmonary artery. In the lungs, the blood picks up oxygen, becoming oxygen-rich blood. This blood then travels from the lungs back to the heart into the left atrium through the mitral valve, then down to the left ventricle. The left ventricle pumps the oxygen-rich blood through the aortic valve and then to the aorta (a large blood vessel) which delivers blood to the body.

  Heart-Lung Connection:
Blood circulation between heart and lungs