The top of the right atrium (atrium dextrum) forms a right ear (auricula dextra), and the extended portion is home to the confluence of large veins. In the right atrium empty into the upper hollow Vienna (v. cava superior), which collects blood from the head, neck, upper extremities and trunk wall, the lower hollow Vienna (v. cava inferior), which collects blood from the walls and the abdominal and pelvic cavities, and lower extremities, the smallest (proper) veins of the heart (vv. cordis minimae), collecting blood from the walls, and coronary sinus, or sinus (sinus coronarius) - the total collector's own cardiac veins. Near the opening of the inferior vena cava is oval fossa (fossa ovalis), which is overgrown with an oval hole through which the embryonic period by communication between the right and left atria.
The right atrium and the anterior surface of the uneven due to the fact that here in the cavity of the atrium pectinate muscle come (mm. pectinati).
The lower part of the right atrium is connected to the right ventricle through the right atrioventricular opening (ostium atrioventriculare dexter). The circumference of this hole is formed protruding into the lumen of the folds - the right atrio-gastric, or tricuspid, valve (valva atrioventricularis dextra, v. tricuspidalis). Valve leaflets are formed by thin fibrous elastic plates. Its function - to close the hole, preventing the reverse flow of blood from the ventricle into the cavity of the oral atrium. This is achieved through thin tendon fibers (chordae tendineae) attached to the free edges of the wings, starting from the papillary muscles (mm. papillares) of the stomach wall, so that during contraction atrial valves are opened only in the direction of the ventricle.
a., aa. — arteria, arteriae (artery, the artery)
lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)
m., mm. — musculus, musculi (muscle, the muscle)
n., nn. — nervus, nervi (nerve, the nerve)
r., rr. — ramus, rami (branch)
s. — seu (or)
v., vv. — vena, venae (vienna)