Right ventricle
Ventriculus dexter
Definition
The right ventricle (ventriculus dexter) is the cranial and ventral chamber of the heart responsible for propelling deoxygenated blood into the pulmonary trunk.
The right ventricle forms most of the cranial (auricular) surface and a large part of the sternocostal surface of the heart. It lies ventral to the left ventricle and to the right of the interventricular septum.
It extends from the right atrioventricular (AV) orifice to the pulmonary valve. Externally, it is separated from the left ventricle ventrocranialy by the paraconal interventricular groove and caudally by the subsinosal interventricular sulcus.
In domestic animals, especially in large animals (horse, ruminants), the right ventricle does not form the apex of the heart; the apex is formed entirely by the left ventricle.
The right ventricular cavity is crescent-shaped in cross section due to the bulging interventricular septum toward the right side. Its wall is thinner than that of the left ventricle because it pumps blood into the low-pressure pulmonary circulation.
The cavity consists of:
Inflow part (sinus of the right ventricle)
Outflow part (conus arteriosus or infundibulum), a smooth-walled cranial portion leading to the pulmonary trunk
The conus arteriosus is separated from the rest of the cavity by a muscular ridge, the supraventricular crest (crista supraventricularis), which directs blood toward the pulmonary valve.
The myocardium is thinner than that of the left ventricle in all domestic species, reflecting lower systolic pressure.
The inner surface presents irregular muscular ridges called trabeculae carneae. These are more prominent in carnivores and pigs and relatively coarser in large animals.
Typically three papillary muscles are present in domestic mammals:
These papillary muscles attach via chordae tendineae to the cusps of the right atrioventricular valve. The number and development may vary among species.
The interventricular septum forms the medial (septal) wall of the right ventricle. It is thicker toward the left side and convex toward the right ventricle.
The pulmonary valve guards the outflow tract at the origin of the pulmonary trunk. It consists of three semilunar cusps in all domestic mammals. Each cusp forms a pulmonary sinus.
There are no chordae tendineae associated with this valve.
The right ventricle receives blood from branches of the coronary arteries. The pattern depends on species-specific coronary dominance.
References
