Heart Chambers: Anatomy and Function of Atria and Ventricles

The heart has four chambers: two atria (receiving) and two ventricles (pumping).

Right Atrium

• Receives: Deoxygenated systemic venous blood via superior/inferior vena cava and coronary sinus.
• Pumps: Blood through tricuspid valve to right ventricle.

Right Ventricle

• Receives: Deoxygenated blood from right atrium.
• Pumps: Blood through pulmonary valve into pulmonary artery → lungs for oxygenation.
• Wall: Thinner (lower pressure circuit).

Left Atrium

• Receives: Oxygenated blood from four pulmonary veins.
• Pumps: Blood through mitral valve to left ventricle.

Left Ventricle

• Receives: Oxygenated blood from left atrium.
• Pumps: Blood through aortic valve into aorta → systemic circulation.
• Wall: Thickest (generates high systemic pressure).

Clinical Relevance

Chamber enlargement or dysfunction underlies heart failure, valvular disease, and arrhythmias. Echocardiography assesses size, wall thickness, and ejection fraction.