Right ventricle (RV)
The right ventricle (RV) is one of the heart chambers located in the inferior right portion of the heart under the right atrium (RA) and opposite to the left ventricle (LV). The main function of the right ventricle is to pump blood up through the pulmonary artery into the lungs, thus providing pulmonary circulation.
The right ventricle has a pyramidal shape, with the base directed upwards, and the apex downwards.
- The right atrioventricular orifice and the opening of the pulmonary trunk are located on the base of the right ventricle.
- The medial wall is formed by the interventricular septum.
- The inferior wall lies close to the central tendon of the diaphragm.
- The anterior wall of the right ventricle is directed towards the inner surfaces of the sternum and ribs.
The part of the heart from which the pulmonary trunk arises is called the infundibulum (or conus arteriosus). It is a conical extension formed from the upper and left angle of the RV in the cordate heart. The inner surface of the RV is smooth only in the infundibulum, elsewhere the muscular layer of the heart creates papillary muscles and irregular muscular columns called trabeculae carneae. The papillary muscles fix the tricuspid valve.
Venous blood from the RA enters the RV through the right atrioventricular orifice. Around the right atrioventricular orifice is the tricuspid valve. The tricuspid valve has three leaflets - the anterior, posterior and septal leaflets. The main function of the tricuspid valve is to prevent backflow of the blood from the ventricles into the atria.
There are three papillary muscles in the right ventricle that attach to the cusps of the atrioventricular valve via the chordae tendinae:
Papillary muscles contract shortly before ventricular systole thus preventing inversion or prolapse of the cusps of the antrioventricular valve into the atrium therefore preventing regurgitation.
Around the opening of the pulmonary trunk is the pulmonary valve, which is a semilunar valve lying between the RV and the pulmonary artery. It has three cusps and it opens up during the ventricular systole.