Major Blood Vessels of the Heart
Coronary Veins | Cardiac Veins
Introduction to the Coronary Veins:
After flowing through the myocardium, most (80%) of the oxygen-depleted blood is returned to the right atrium by several prominent veins that run along the surface of the heart (= epicardial veins).
- Draining blood from the anterior ventricles is the great cardiac vein.
- This vessel originates at the apex of the heart and runs superiorly along the anterior interventricular sulcus (next to the anterior interventricular artery).
- Near the left atrium, the great cardiac vein veers to the left and enters the coronary sulcus (= between the left atrium and ventricle), where it extends to the back side of the heart.
- One or more left marginal veins typically merge with the great cardiac vein as it traverses the lateral ventricular wall.
- Small anterior cardiac veins also drain blood from the anterior right ventricle directly into the right atrium.
- Blood is removed from the lateral and posterior right ventricle (and atrium) by the small cardiac vein, which travels to the posterior surface of the heart in the coronary sulcus (= between the right atrium and ventricle).
- Along its path, the small cardiac vein receives blood from one or more right marginal veins.
- On the posterior side of the heart, the great and small cardiac veins merge with the coronary sinus, which empties into the right atrium.
- The coronary sinuses also receives blood from the middle cardiac vein that ascends along the posterior interventricular groove and the posterior vein of the left ventricle.
- About 20% of the deoxygenated blood flows directly into the heart cavities from numerous Thebesian veins (= venae cordis minimae) in the myocardium, especially in the left atrium.
- These small cardiac veins are named after Adam Christian Thebesius, a prominent German anatomist who studied heart circulation in the early 1700’s.