Physiology · Cardiovascular System

Coronary circulation and its regulation

5 min read

Definition

  • Coronary circulation is the heart's own blood supply, via right and left coronary arteries arising from the aortic root behind the valve cusps.
  • Normal coronary blood flow is about 250 ml/min (84 ml/100 g cardiac tissue/min), about 4.7% of cardiac output.

Arterial Supply and Venous Drainage

  • RCA supplies the right atrium and right ventricle.
  • LCA supplies the left atrium and left ventricle.
  • No anastomoses exist between them, so coronary arteries are end arteries with non-overlapping territories.
  • Sinuses of Valsalva (outpouches of the aorta behind the semilunar cusps) generate eddy currents that keep the valve cusps away from the coronary ostia in systole, allowing coronary filling.
  • Venous drainage
    • Major: coronary sinus and anterior cardiac veins, into the right atrium.
    • Minor: arteriosinusoidal, thebesian and arterioluminal vessels, draining directly into cardiac chambers.