Part 5/10:
The Human Heart: Comprising four chambers—two atria and two ventricles—it's a muscular pump that contracts rhythmically. The heartbeat, or cardiac cycle, alternates between diastole (relaxation and filling) and systole (contraction and pumping).
Valves and their Function: Key valves, including the tricuspid, pulmonary, mitral, and aortic valves, prevent backflow and ensure unidirectional blood flow through chambers and arteries.
Flow of Blood: Deoxygenated blood from the body enters the right atrium, proceeds to the right ventricle, then pumps via the pulmonary arteries to the lungs. Oxygenated blood returns through pulmonary veins to the left atrium, then passes into the left ventricle, which pumps it through the aorta to systemic tissues.