Coronary sinus
Encyclopedia
The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart
. It is present in all mammals, including humans. It delivers deoxygenated blood to the Right atrium
in conjunction with the superior and inferior vena cava.
The coronary sinus opens into the right atrium
, between the inferior vena cava and the atrio-ventricular orifice. It returns the blood from the substance of the heart, and is protected by a semicircular fold of the lining membrane of the auricle, the coronary valve (the valve of Thebesius). The sinus, before entering the auricle, is considerably dilated - nearly to the size of the end of the little finger. Its wall is partly muscular, and at its junction with the great coronary vein is somewhat constricted and furnished with a valve consisting of two unequal segments.(Gray 462)
The coronary sinus orifice (opening) is just superior to the septal leaflet of the tricuspid valve
. The coronary sinus orifice is also known as the ostium of the coronary sinus, and is guarded by the Thebesian valve
.
, middle
, great
and oblique cardiac veins. It also receives blood from the left marginal vein
and the left posterior ventricular vein. The anterior cardiac veins
drain directly into the right atrium
. (Some small veins drain into any of the four chambers of the heart.)
It drains into the right atrium
on the posterior, inferior surface, medial to the inferior vena cava opening.
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
. It is present in all mammals, including humans. It delivers deoxygenated blood to the Right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
in conjunction with the superior and inferior vena cava.
The coronary sinus opens into the right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
, between the inferior vena cava and the atrio-ventricular orifice. It returns the blood from the substance of the heart, and is protected by a semicircular fold of the lining membrane of the auricle, the coronary valve (the valve of Thebesius). The sinus, before entering the auricle, is considerably dilated - nearly to the size of the end of the little finger. Its wall is partly muscular, and at its junction with the great coronary vein is somewhat constricted and furnished with a valve consisting of two unequal segments.(Gray 462)
Location
It is located in the right atrium and runs transversely in the groove between the left atrium and ventricle on the posterior surface of the heart.The coronary sinus orifice (opening) is just superior to the septal leaflet of the tricuspid valve
Tricuspid valve
The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, between the right atrium and the right ventricle. The normal tricuspid valve usually has three leaflets and three papillary muscles. They are connected to the papillary muscles by the chordae...
. The coronary sinus orifice is also known as the ostium of the coronary sinus, and is guarded by the Thebesian valve
Valve of the coronary sinus
The valve of the coronary sinus is a semicircular fold of the lining membrane of the right atrium, at the orifice of the coronary sinus.The valve may vary in size, or be completely absent....
.
Drainage
It receives blood mainly from the smallSmall cardiac vein
The small cardiac vein runs in the coronary sulcus between the right atrium and ventricle, and opens into the right extremity of the coronary sinus.It receives blood from the back of the right atrium and ventricle....
, middle
Middle cardiac vein
The middle cardiac vein commences at the apex of the heart, ascends in the posterior longitudinal sulcus, and ends in the coronary sinus near its right extremity.-External links: - "Posterior view of the heart."...
, great
Great cardiac vein
The Great Cardiac Vein begins at the apex of the heart and ascends along the anterior longitudinal sulcus to the base of the ventricles....
and oblique cardiac veins. It also receives blood from the left marginal vein
Left marginal vein
The great cardiac vein receives tributaries from the left atrium and from both ventricles: one, the left marginal vein, is of considerable size, and ascends along the left margin of the heart....
and the left posterior ventricular vein. The anterior cardiac veins
Anterior cardiac veins
The anterior cardiac veins , comprising three or four small vessels which collect blood from the front of the right ventricle and open into the right atrium; the right marginal vein frequently opens into the right atrium, and is therefore sometimes regarded as belonging to this groupUnlike most...
drain directly into the right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
. (Some small veins drain into any of the four chambers of the heart.)
It drains into the right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
on the posterior, inferior surface, medial to the inferior vena cava opening.