Right ventricle

At a glance

English

Right ventricle

Latin (TA2)

Ventriculus dexter

System

Heart

Region

Trunk

Side

Single, on the midline

About the right ventricle

The right ventricle takes in blood low in oxygen from the right atrium, by way of the tricuspid valve, and sends it into the pulmonary trunk through the pulmonary valve. It lies in front of the left ventricle and makes up the greater part of the heart's sternocostal surface, as well as the sharp inferior border and part of the diaphragmatic surface. It is the chamber most directly behind the sternum.

Its cavity is triangular when seen from the front and crescent-shaped in cross-section, because the interventricular septum bulges into it from the left. It wraps round the left ventricle rather than forming a cone of its own. Its wall is much thinner than the left's, since it pumps into the low-pressure lung circulation. Two regions are described. The inflow part, behind the tricuspid valve, is rough with trabeculae carneae and carries the anterior, inferior and septal papillary muscles. The outflow part, the conus arteriosus or infundibulum, is smooth-walled and funnels blood upwards and to the left into the pulmonary trunk. A thick muscular ridge, the supraventricular crest, separates the two.

A muscle bundle called the septomarginal trabecula, or moderator band, crosses the cavity from the septum to the foot of the anterior papillary muscle. It carries the right bundle branch of the conducting system, so that this papillary muscle contracts in time to tense its cords before the valve is loaded.

Being thin-walled, the right ventricle copes poorly with a sudden rise in lung pressure, such as a large pulmonary embolus, and can fail acutely. Chronic lung disease thickens and enlarges it. Its position behind the sternum makes it the chamber most at risk in stab wounds of the front of the chest.

Function and supply

Function

Drives deoxygenated blood past the pulmonary valve and on into the pulmonary trunk and so through the lungs.

Nerve supply

Sympathetic and vagal fibres from the cardiac plexus; contraction is timed by the right bundle branch, much of which runs in the moderator band.

Blood supply

Mainly the right coronary artery and its marginal branch, with a strip next to the anterior groove from the anterior interventricular artery; veins drain to the coronary sinus and directly into the right atrium.