What is the main purpose of cardiac output in the body?

The main purpose of cardiac output is to pump blood through the circulatory system, making option C the correct choice. Cardiac output refers to the volume of blood that the heart pumps per minute. It is a critical factor in ensuring that oxygen and nutrients are delivered to the tissues of the body, while also facilitating the removal of carbon dioxide and other metabolic waste products.

The heart's ability to maintain an adequate cardiac output is essential for sustaining the body's physiological functions during rest and exercise. When physical activity increases, the demand for oxygen in the muscles rises, and the heart responds by increasing cardiac output to meet these heightened needs.

Understanding cardiac output is crucial for various contexts, including assessing cardiovascular fitness, managing heart conditions, or designing exercise programs. Thus, its primary role is foundational to the overall functioning of the body's circulatory system.