The heart is a key component of which body system?

The heart is an essential component of the circulatory system, which is responsible for transporting blood throughout the body. This system plays a critical role in delivering oxygen and nutrients to cells and removing waste products like carbon dioxide. The heart pumps blood through a network of blood vessels, ensuring that every part of the body receives the necessary substances for functioning.

In contrast, the immune system focuses on defending the body against infections and diseases; the skeletal system provides structure and support to the body and includes bones and joints; while the respiratory system is involved in the exchange of gases, specifically oxygen and carbon dioxide. These other systems do not center around the heart's primary function, making the circulatory system the correct association for the heart.