What are the functions of the ventricles?

• A. They are thin-walled receiving chambers
• B. They are high-pressure chambers that pump blood out of the heart
• C. They store blood between beats
• D. They primarily regulate heart rate

Answer: (B)

Ventricles are the heart’s high-pressure pumping chambers that eject blood into the circulation. Their thick muscular walls generate the force needed to push blood out of the heart—the right ventricle sends blood to the lungs via the pulmonary circulation, while the left ventricle sends blood to the rest of the body via the aorta. They contract during systole to propel blood and relax during diastole to fill from the atria. In contrast, the thin-walled atria act as receiving chambers that collect blood and channel it to the ventricles, rather than pumping it out at high pressure. Heart rate regulation is controlled by the conduction system and autonomic input, not by the ventricles themselves.