Which chamber acts as the primary systemic pump, delivering oxygenated blood to the body?

• A. Right atrium
• B. Left atrium
• C. Left ventricle
• D. Right ventricle

Answer: (C)

Delivering oxygen-rich blood to the body's tissues relies on the left ventricle. Blood returns from the lungs to the heart into the left atrium, passes through the mitral valve into the left ventricle, and when the left ventricle contracts, it ejects blood into the aorta—the main arterial highway to all organs. The left ventricle has a thick, powerful muscular wall because it must generate the high pressure needed to overcome systemic vascular resistance and maintain arterial blood flow. In contrast, the right atrium collects deoxygenated blood from the body, and the right ventricle sends that blood to the lungs at a much lower pressure. The left atrium then collects oxygenated blood from the lungs to feed the left ventricle again. So the chamber that serves as the primary pump delivering oxygenated blood to the body is the left ventricle.