There are four chambers in a human heart - two atria and two ventricles.

• The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle.
• The right ventricle pumps the oxygen-poor blood to the lungs.
• The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle.
• The right ventricle is the chamber within the heart that is responsible for pumping oxygen-depleted blood to the lungs.