The cardiovascular system consists of (Pick 3).

• A. Heart; Blood; Blood Vessels
• B. Heart; Lungs; Blood
• C. Heart; Nerves; Blood
• D. Heart; Lymph; Blood

Answer: (D)

The cardiovascular system is built from the pump, the fluid it moves, and the vessels that carry it. The heart acts as the pump that generates the pressure to circulate blood through two main circuits: to the lungs for oxygenation and to the rest of the body for delivery of oxygen, nutrients, and removal of wastes. Blood is the circulating fluid that transports these substances and participates in immune functions and temperature regulation. Blood vessels—arteries, veins, and capillaries—form the network through which blood travels to every tissue and back to the heart.

Lymph belongs to the lymphatic system, which supports fluid balance and immunity but is not part of the cardiovascular system, though it interacts with it. Lungs are part of the respiratory system, handling gas exchange, and nerves belong to the nervous system. Therefore, the three components that make up the cardiovascular system are the heart, blood, and blood vessels.