Right ventricle
The right ventricle is the heart’s most anterior chamber, seamlessly continuing from the right atrium. Situated anteriorly and to the left of the right atrioventricular orifice, it receives blood from the right atrium. The right ventricle has a triangular shape and comprises three main parts: an inlet, a trabecular region, and an outlet, each contributing to its essential role.
Inlet of right ventricle
The Inlet of right ventricle is the part of the ventricle that contains the tricuspid valve with its chordae and papillary muscles.
Supraventricular crest
Right above the tricuspid valve there is a prominent muscular ridge within the right ventricle, this is known as the supraventricular crest.
Conus arteriosus (Outlet component of the Right ventricle / Infundibulum)
Above the supraventricular crest within the heart’s architecture lies the conus arteriosus, also known as the infundibulum. This conical pouch resides in the upper part of the right ventricle, playing a pivotal role in supporting the pulmonary valve. Serving as the outflow tract of the right ventricle, it guides the blood flow outside the right ventricle.
Trabecular part of right ventricle
The third segment of the right ventricle, connecting the inlet to the outlet, is termed the trabecular part. This region is characterized by its irregular, mesh-like muscle projections, giving it a unique texture and appearance.
While this might seem to complicate the heart’s anatomy further, this complex network within the trabecular part is crucial for the heart’s efficient functioning,
The trabecular part extends to the heart’s apex, and it’s thin walls are reinforced with muscle bands, known as trabeculations.
Trabeculations might vary in form.
Some trabeculations are anchored along the ventricular walls, forming pronounced ridges. Other trabeculations stretch across, creating arch-like bridges. Some projections are connected at one end to the ventricular surface and at the other to the tricuspid valve, known as papillary muscles.
Papillary muscles of right ventricle
The papillary muscles. Numbering three (the anterior papillary muscle, the inferior papillary muscle and the septal papillary muscle) anchor the chordae tendineae, which are crucial for the operation of the right ventricle.
The papillary muscles, essentially specialized trabeculae carneae, are uniquely positioned within the ventricular cavity and vary in size, consistency, and origin.
Anterior papillary muscle of right ventricle
The anterior papillary muscle, is the largest and most consistent papillary muscle associated with the tricuspid valve. It is supported by a specialized trabeculum, and originate from the anterior wall of the ventricle.
Inferior papillary muscle of right ventricle
The inferior, or posterior, papillary muscle, the second largest, arises from the ventricle’s lower section. It can vary in structure, sometimes presenting as one, or more separate muscles.
Septal papillary muscle of right ventricle
The septal papillary muscle, often the smallest and most variable, may range from small to non-existent.
Chordae tendinae of right atrioventricular valve
Chordae tendineae act as fibrous strings that connect the valve leaflets to the papillary muscles.
In the right ventricle, the septal leaflet of the tricuspid valve is directly anchored to the septum.
Trabeculae carneae of right ventricle
These trabeculae carneae are essential in providing the right ventricle with its rugged appearance, facilitating cardiac function by aiding in the contraction process and contributing significantly to its unique internal structure.
Septomarginal trabecula (Moderator Band)
Among these trabeculae, the septomarginal trabecula stands out due to its critical role. It is a muscular band that connects the anterior papillary muscle to the interventricular septum. This single specialized trabeculum forms a direct path between the lower portion of the interventricular septum and the base of the anterior papillary muscle. Notably, the septomarginal trabecula carries a portion of the cardiac conduction system.
Coarse apical trabeculations
Additionally, the right ventricle features coarse apical trabeculations within its trabecular part. These raised muscular bands are more pronounced than those found in the left ventricle, contributing to the right ventricle’s ability to pump blood efficiently through the pulmonary circuit.