In Depth: Cross-section
The chambers of the heart operate as a ‘double-pump’ system for the body’s circulation. In coordination with valves, the chambers work to keep blood flowing in the proper sequence.
The chambers on the right side of the heart pump oxygen-depleted blood from the organs and to the lungs, where it absorbs oxygen. After the blood leaves the lungs and returns to the heart, the left-sided chambers pump the oxygenated blood around to all the tissues of the body.
The heart’s four chambers are:
- Right atrium: This thin-walled chamber receives blood from body tissues and pumps it into the right ventricle.
- Right ventricle: The right ventricle pumps blood from the right atrium to the pulmonary trunk and out to the lungs via the pulmonary arteries.
- Left atrium: This chamber receives oxygenated blood from the lungs and then pumps it to the left ventricle.
- Left ventricle: The thickest of all the chambers, the left ventricle is the hardest working part of the heart as it pumps blood throughout the entire body.
To keep this continually flowing process moving in the right direction, the heart contains four valves to prevent the backflow of blood.
Each of the four chambers of the heart has its own valve. They are:
- Tricuspid valve: This valve is located between the right atrium and right ventricle. It is also called the right AV valve.
- Pulmonary valve: The pulmonary valve is the checkpoint where deoxygenated blood leaves the right ventricle on its way to the lungs.
- Mitral valve: The mitral valve is located between the left atrium and left ventricle. It is also called the left AV valve.
- Aortic valve: This valve is the last stop for blood as oxygen-rich blood pumps out of the left ventricle and out to the entire body.
Sometimes valves become damaged and need to be repaired or replaced through a surgical procedure known as a median sternotomy. Replacement heart valves currently available are either mechanical or made from animal or human tissue.
During heart valve replacement surgery, a surgeon cuts through a person’s sternum to gain access to the heart while the person is hooked up to a cardiopulmonary bypass machine, which takes over the person’s heartbeat and respiration during the procedure.
If the process goes without complication, a patient’s hospital stay for valve replacement surgery is in the range of 3 to 7 days.