The human heart functions as a muscular pump, divided into four chambers to manage circulation. The right ventricle (RV) is one of the two lower chambers, situated on the right side of the heart. It receives blood from the upper right chamber, the right atrium, acting as the starting point for circulation to the lungs.
Driving the Pulmonary Circuit
The primary responsibility of the right ventricle is to propel deoxygenated blood into the pulmonary circulation, the pathway leading directly to the lungs. Blood returning from the body, having delivered oxygen and collected carbon dioxide, enters the right ventricle. This chamber must generate sufficient force to move this volume of blood through the extensive network of vessels in the lungs.
This continuous pumping action routes the blood to the capillaries surrounding the lung’s air sacs. The purpose is gas exchange, where the blood drops off carbon dioxide and replenishes its supply of oxygen. The right ventricle’s output is precisely matched to the left ventricle’s output, meaning both sides of the heart move the same volume of blood per beat. This synchronized function ensures the systemic circulation is constantly supplied with oxygen-rich blood.
Anatomical Specialization for Low Pressure
The right ventricle is uniquely constructed to handle a high volume of blood while operating under low pressure. This contrasts with the muscular left ventricle, which must generate greater force to push blood to the entire body. The pulmonary circulation is a low-resistance system, meaning it does not require a high-pressure push to circulate blood effectively.
The right ventricle’s muscular wall is thinner than the left ventricle’s, reflecting the difference in pressure demands. While the left ventricle is conical and thick-walled, the right ventricle has a crescent or C-shape, wrapping around the larger left ventricle. The contraction mechanism relies on a bellows-like motion and the action of the shared interventricular septum. This architectural difference allows the right ventricle to accommodate large blood volume changes without significantly increasing pressure, preventing damage to the delicate lung capillaries.
The Step-by-Step Flow of Deoxygenated Blood
The movement of blood through the right ventricle is controlled by two valves that ensure one-way flow. Deoxygenated blood enters the right ventricle from the right atrium by passing through the tricuspid valve. This valve, which typically has three flaps, opens to allow filling during the heart’s relaxation phase, known as diastole.
Once the right ventricle is adequately filled, the heart begins its contraction phase, or systole, which causes the tricuspid valve to snap shut. The closing of this valve prevents backward flow of blood into the right atrium as the ventricle’s pressure begins to rise. Simultaneously, the pulmonic valve (pulmonary valve) opens up. This allows the contracting ventricle to eject the blood forward into the pulmonary artery, beginning the journey to the lungs for oxygenation.
Consequences of Right Ventricle Dysfunction
When the right ventricle loses its ability to pump blood efficiently, right-sided heart failure occurs. This failure means the ventricle cannot effectively move blood into the lungs, causing congestion and backup of blood. The excess blood volume and pressure then accumulate backward into the body’s main veins and the systemic circulation.
This systemic congestion leads to several clinical signs because fluid is pushed out of the vessels and into the surrounding tissues. A common symptom is peripheral edema, which is swelling, particularly in the lower extremities (feet, ankles, and legs). Fluid can also back up into the abdomen, causing abdominal distension and liver congestion. The resulting increased pressure in the neck veins can be visible, a sign known as jugular venous distension.