cardiac chambers (anatomy)

Last reviewed 01/2018

There are four chambers within the heart, two atria and two ventricles.

• right atrium:
• receives deoxygenated blood from the superior and inferior venae cavae
• conveys it to the right ventricle through the tricuspid valve
• left atrium:
• receives oxygenated blood from the pulmonary veins
• conveys it to the left ventricle through the mitral valve
• left ventricle:
• receives oxygenated blood from the left atrium
• conveys it to the rest of the body through the aortic valve
• right ventricle:
• receives deoxygenated blood from right atrium
• conveys it to the pulmonary trunk through the pulmonary valve

Clinically, the chambers have a functional pairing as 'sides of heart':

• the right atrium and ventricle are in series with each other to convey deoxygenated blood to the lungs at relatively low pressure
• the left atrium and ventricle are in series with each other to convey oxygenated blood to the systemic circulation at relatively high pressure

Physiologically, there is another functional pairing to assist with the efficiency of pumping of the whole organ:

• the atria contract simultaneously
• the ventricles contract simultaneously
• due to the electrical conduction system between chambers, the atria contract prior to ventricles

The anatomy of individual chambers is considered in the submenu.