Which organ is responsible for pumping blood throughout the body?

The heart is the organ responsible for pumping blood throughout the body. It functions as a muscular pump that circulates oxygenated blood from the lungs to the rest of the body and returns deoxygenated blood back to the lungs for re-oxygenation. This process is crucial for maintaining the body's overall health, as it ensures that all organs and tissues receive the necessary nutrients and oxygen to function properly.

The heart operates through a coordinated system of contractions, with the right side of the heart receiving deoxygenated blood and the left side distributing oxygen-rich blood. This two-pump system works continuously, managing the circulatory system’s efficiency.

The other options—brain, liver, and lungs—have important roles in the body but do not pump blood. The brain regulates many bodily functions, including heart rate, the liver processes nutrients and detoxifies, and the lungs facilitate gas exchange, but they do not have the capability to pump blood. This distinction emphasizes the heart’s unique and vital role in circulation.