Congestive Heart Failure


The Heart and Its Pumping Action
The heart is composed of two independent pumping systems, one on the right side, the other on the left. Each has two chambers, an atrium and a ventricle. The ventricles are the major pumps in the heart.

The Right Side of the Heart. The right system receives blood from the veins of the whole body. This is “used”  blood, which is poor in oxygen and rich in carbon dioxide.

  * The right atrium is the first chamber that receives blood.

  * The chamber expands as its muscles relax to fill with blood that has returned from the body.

  * The blood enters a second muscular chamber called the right ventricle.

  * The right ventricle is one of the heart’s two major pumps. Its function is to pump the blood into the lungs.

  * The lungs restore oxygen to the blood and exchange it with carbon dioxide, which is exhaled.

The Left Side of the Heart. The left system receives blood from the lungs. This blood is now oxygen rich.

  * The oxygen-rich blood returns through veins coming from lungs (pulmonary veins) to the heart.

  * It is received from the lungs in the left atrium, the first chamber on the left side.

  * Here, it moves to the left ventricle, a powerful muscular chamber that pumps the blood back out to the body.

  * The left ventricle is the strongest of the heart’s pumps. Its thicker muscles need to perform contractions powerful enough to force the blood to all parts of the body.

  * This strong contraction produces systolic blood pressure (the first and higher number in blood pressure measurement). The lower or diastolic blood pressure is measured when the left ventricle relaxes to refill with blood between beats.

  * Blood leaves the heart through the ascending aorta, the major artery that feeds blood to the entire body.

The Valves. Valves are muscular flaps that open and close so blood will flow in the right direction. There are four valves in the heart:

  * The tricuspid regulates blood flow between the right atrium and the right ventricle.

  * The pulmonary valve opens to allow blood to flow from the right ventricle to the lungs.

  * The mitral valve regulates blood flow between the left atrium and the left ventricle.

  * The aortic valve allows blood to flow from the left ventricle to the ascending aorta.

The Heart’s Electrical System.

The heartbeats are triggered and regulated by the conducting system, a network of specialized muscle cells that form an independent electrical system in the heart muscles. These cells are connected by channels that pass chemically caused electrical impulses.

Johns Hopkins patient information

Last revised:

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.