Trabeculae carneae

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Anatomy and function of the right ventricle.

The trabeculae carneae are characteristic irregular, endocardial-lined, muscular ridges and elevations located on the internal wall surfaces of both ventricles of the heart. They are finer, more delicate, and more abundant in the left ventricle compared to the right ventricle.

These muscular projections vary in size and shape and are either connected to the walls of the ventricles along their entire length, forming ridges, or are connected at both ends, creating bridges.

Each ventricle features large cone-shaped trabeculae carneae known as papillary muscles which are anchored at one end to the surface of the ventricle. The opposite end is connected to thin, tendon-like structures called chordae tendineae, which extend to attach to the free edges of the tricuspid and mitral valve cusps in the right and left ventricles, respectively. The chordae tendineae function to prevent the inversion of the valves into the atrium during ventricular contraction.

The right ventricle also contains a specialized trabeculum known as the septomarginal trabecula, or the moderator band, which bridges the lower part of the interventricular septum to the base of the anterior papillary muscle. It transports a part of the heart's conduction system, specifically the right bundle branch of the atrioventricular bundle, to the anterior wall of the right ventricle.