Learn about the heart anatomy, including its chambers, valves, blood flow, and coronary circulation. See diagrams, videos, quizzes, and clinical notes on the heart structure and functions. Explore the heart anatomy with its parts, names & a clear diagram. Learn how the heart functions & its crucial role in the circulatory system Learn about the layers, chambers, valves, and blood supply of the human heart , a four-chambered muscular organ that pumps blood through the body. The web page also explains the pathway of blood through the heart and the difference between the right and left sides of the heart . The heart cavity is divided down the middle into a right and a left heart, which in turn are subdivided into two chambers. The upper chamber is called an atrium (or auricle), and the lower chamber is called a ventricle.