Veins of the Heart.

Veins of the heart or cardiac veins refer to the veins that drain the blood supply of the heart wall. At the minutest scale of the circulatory system, the venules collect the deoxygenated and metabolic waste rich blood from the capillary beds. The venules then  join together to form the veins.

The heart veins collect deoxygenated blood containing metabolic waste from the myocardium and return it to the right atrium via the coronary sinus. These cardiac veins are typically free of atherosclerotic plaques and contain valves which allow only forward flow of blood.

The Coronary Sinus.

The coronary sinus is a 2.25 cms long venous channel which opens into the right atrium near the openings of the superior and inferior venae cavae. It is situated in the posterior part of the coronary sulcus and covered by muscle fibers of the left atrium.

The coronary sulcus is a groove that separates the atria from the ventricles. It is also called the atrioventricular groove, the auriculoventricular groove or the coronary groove. Its opening into the right atrium or the ostium of the coronary sinus is guarded by a semilunar valve called the Valve of Thebesius or the valve of the coronary sinus.

Cardiac Veins.

The following coronary veins are the tributaries of the coronary sinus.

The Great Cardiac Vein or The Left Coronary Vein.

The great cardiac vein begins at the apex of the heart and proceeds along the anterior longitudinal sulcus to the base of the ventricles, from where it curves to the left along the coronary sulcus to the left end of the coronary sinus. On its route this heart vein receives tributaries from the left atrium and from the ventricles. One such tributary is the left marginal vein which is of considerable size and proceeds along the left border of the heart.

The Small Cardiac Vein or The Right Coronary Vein.

The small cardiac vein runs along the coronary sulcus between the right atrium and the right ventricle and empties into the right end of the coronary sinus. It drains the back of the right atrium and the right ventricle. Its main tributary, the right marginal vein ascends along the right border of the heart and joins it in the coronary sulcus or may open directly into the right atrium.

1. The Middle Cardiac Vein begins at the apex of the heart, climbs in the posterior longitudinal sulcus and ends in the coronary sinus at its right end.
2. The Posterior Vein of the Left Ventricle runs along the diaphragmatic surface of the left ventricle to end in the coronary sinus. Sometimes it may end in the great cardiac vein.
3. The Oblique Vein of the Left Atrium is a small vein which descends diagonally along the back surface of the left atrium to end in the left extremity of the coronary sinus.

Picture of heart veins.

Veins That Open Directly into the Heart and Not the Coronary Sinus.

1. The anterior cardiac veins comprise four to five small veins which drain the front surface of the right ventricle and open directly into the right atrium.
2. The smallest cardiac veins consist of small veins which arise from the heart muscle wall and open in the atria.

Related posts:

1. Varicose Veins.
2. Blood Flow in the Heart.
3. Right Atrium of the Heart.
4. Coronary Arteries|Arteries of the Heart.
5. Heart Chambers.
6. Heart Anatomy and Structure.
7. Parts of the Heart.
8. What Does Heart Do|Function of Heart.