Tricuspid Valve in a Transverse Section of the Male Heart, Ventral View

Description

Oriented ventrally in a transverse section through the atrioventricular plane, the right atrium lies superior to the right ventricle, with the tricuspid valve interposed at the right atrioventricular orifice. Three tricuspid cusps (anterior, posterior, and septal leaflets) attach circumferentially to the fibrous annulus, their free margins projecting inferiorly into the right ventricular inflow tract. Medially, the septal leaflet sits adjacent to the interventricular septum; laterally, the anterior leaflet faces the right ventricular free wall, while the posterior leaflet occupies the inferior portion of the annulus near the diaphragmatic surface. Parts of the left-sided chambers appear in the same slice, and superiorly the outflow tracts approach the semilunar valves, with the aortic root and pulmonary trunk recognizable in cross-section. A ventral transverse cut is the teaching workhorse for explaining why the tricuspid valve behaves differently than the mitral valve: the right-sided annulus is larger, more compliant, and functionally tied to right ventricular geometry. That matters in functional tricuspid regurgitation, where annular dilation and leaflet malcoaptation accompany right ventricular remodeling from pulmonary hypertension or left-sided heart disease, often with a relatively normal-appearing leaflet tissue. Clear septal-versus-anterior leaflet relationships also map to procedural risk, since the atrioventricular node and bundle of His lie near the septal annulus (triangle of Koch), a point surgeons and electrophysiologists treat with respect. Use this plate for cardiothoracic anatomy labs, valve pathology chapters, and perioperative teaching when discussing tricuspid annuloplasty, endocarditis patterns, or device lead related tricuspid regurgitation in the right atrium and ventricle. It also fits radiology and echocardiography primers that bridge sectional anatomy to standard mid-esophageal and transgastric views. Anatomical accuracy verified by SciePro's Medical Advisory Board.