In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The atrium (an adjacent/upper heart chamber that is smaller than a ventricle) primes the pump. Interventricular means between the ventricles (for example the interventricular septum), while intraventricular means within one ventricle (for example an intraventricular block).

A four-chambered heart, such as that in humans, there are two ventricles that operate in a double circulatory system: the right ventricle pumps blood into the pulmonary circulation to the lungs, and the left ventricle pumps blood into the systemic circulation through the aorta.

The right ventricle is equal in size to that of the left ventricle[citation needed], and contains roughly 85 millilitres (3 imp fl oz; 3 US fl oz) in the adult. Its upper front surface is circled and convex, and forms much of the sternocostal surface of the heart. Its under surface is flattened, forming part of the diaphragmatic surface of the heart that rests upon the diaphragm.

It’s posterior wall is formed by the ventricular septum, which bulges into the right ventricle, so that a transverse section of the cavity presents a semilunar outline. Its upper and left angle forms a conical pouch, the conus arteriosus, from which the pulmonary artery arises. A tendinous band, called the tendon of the conus arteriosus, extends upward from the right atrioventricular fibrous ring and connects the posterior surface of the conus arteriosus to the aorta.