Anatomy, nomenclature and function of the normal heart

Abstract

The heart consists of four cavities, separated from each other by walls and valves. The blood enters the heart in the right atrium via the superior vena cava (upper part of the body) and the inferior vena cava (lower part of the body). Both vessels have no valves. The wall of the right atrium is only a few millimeters thick. The right atrium is separated from the right ventricle by the tricuspid ring (annulus) and -valve. The ring consists of fibrous tissue. The tricuspid valve has three leaflets, the anterior, the posterior and the medial (or septal) leaflet which are connected to the papillary muscles with a number of chordae tendinae. The papillary muscles are part of the right ventricular wall. The right ventricle partly surrounds the left ventricle and ends in the right ventricular outflow tract at the pulmonic valve. The pulmonic valve consists of three cusps, the anterior, the right and the left cusp. The blood then passes through the pulmonary artery via the main branches, the right and left pulmonary artery.