The human heart is a muscular organ responsible for pumping blood throughout the body, supplying oxygen and nutrients to tissues, and removing waste products. It has four chambers: two atria (upper chambers) and two ventricles (lower chambers). Blood flows through the heart in a specific sequence: oxygen-poor blood enters the right atrium, moves to the right ventricle, and is pumped to the lungs for oxygenation. Oxygen-rich blood returns to the left atrium, flows into the left ventricle, and is pumped to the rest of the body. The heart’s rhythmic contractions are controlled by electrical signals, ensuring efficient circulation. It plays a crucial role in maintaining overall health and homeostasis.