Which of the following is a function of the cardiovascular system?

• A. Gas exchange
• B. Hormone transport
• C. Blood flow
• D. Absorption of nutrients

Answer: (C)

The essential idea is what the cardiovascular system primarily does: move blood through the body. Blood flow—the continual pumping of the heart and the network of vessels—provides the mechanism that keeps every cell nourished and cared for. It delivers oxygen and nutrients where they’re needed and carries away carbon dioxide and other wastes. It also serves as the highway for hormones traveling to their targets, but the defining function described is the circulation of blood itself. Gas exchange happens mainly in the lungs and at tissue surfaces, and nutrient absorption is a function of the digestive system, so those aren’t the core roles of the cardiovascular system.