Which side of the heart is the low-pressure side of the cardiovascular system?

• A. Left Side
• B. Right Side
• C. Anterior Side
• D. Posterior Side

Answer: (B)

The heart operates two circuits with different pressures: the pulmonary circuit on the right handles blood flow to the lungs at low pressure, while the systemic circuit on the left pumps blood to the entire body at high pressure. Because the right ventricle sends blood into the lungs with relatively little resistance, its pressure is much lower and its walls are thinner. In contrast, the left ventricle must generate high pressure to overcome systemic vascular resistance, so it has thicker walls. Therefore, the right side is the low-pressure side of the cardiovascular system. Anterior and posterior are just anatomical orientations, not related to pressure, and the left side is the high-pressure side.