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 …

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 …

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 …

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.