In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest, called the mediastinum. [4]

Dec 6, 2025 · Heart, organ that serves as a pump to circulate the blood. It may be as simple as a straight tube, as in spiders and annelid worms, or as complex as the four-chambered double pump …

Your heart is the main organ of your cardiovascular system, a network of blood vessels that pumps blood throughout your body.

Mar 24, 2022 · This image shows the four chambers of the heart and the direction that blood flows through the heart. Oxygen-poor blood, shown in blue-purple, flows into the heart and is pumped out …

Dec 14, 2025 · Blood is carried through the body in blood vessels called arteries and veins. The process of moving blood through the body is called circulation. Together, the heart and vessels make up the …

Oct 1, 2025 · Your heart is an essential organ in your body. It functions as a muscle that pumps blood nonstop and sends oxygen and nutrients to other organs.

Oct 19, 2025 · The cardiovascular system includes the heart and blood vessels. This article covers normal and abnormal circulatory system function.