The Coronary Circulation

BLOOD SUPPLIED TO THE HEART (THE CORONARY CIRCULATION)

The heart muscle itself requires a continuous supply of oxygen and nutrients to function efficiently. This supply is provided by a special circulation known as coronary circulation.

Arterial Supply

The arterial blood supply to the heart is provided by two coronary arteries:

• Right coronary artery
• Left coronary artery

These arteries arise from the ascending aorta, just above the aortic valve.

Although the heart is relatively small in size, it receives about 5% of the total cardiac output. This rich blood supply is essential because the heart works continuously without rest. The coronary arteries branch extensively and form a dense network of capillaries within the myocardium.

Venous Drainage

Most of the venous blood from the heart muscle is collected by cardiac veins, which unite to form the coronary sinus. The coronary sinus opens into the right atrium.

A small amount of venous blood drains directly into the heart chambers through small veins.