Final answer:
The heart pumps blood through its four chambers, coordinated by an electrical conduction system. Valves ensure one-way blood flow and the left ventricle sends oxygen-rich blood to the body's circulatory system.
Step-by-step explanation:
Structure and Function of the Heart
The human heart is a complex organ that pumps blood through the circulatory system, comprising the coronary, pulmonary, and systemic circulations. Inside the heart, there are four chambers: two atria and two ventricles. The flow of blood begins when oxygen-poor blood enters the right atrium through the veins. It then travels through the tricuspid valve into the right ventricle. From there, it is pumped through the pulmonary valve to the lungs via the pulmonary artery. After obtaining oxygen, blood returns to the left atrium and is then pushed through the mitral valve into the left ventricle. Finally, the left ventricle pumps oxygen-rich blood through the aortic valve into the aorta and subsequently to the rest of the body.
Blood flow is carefully regulated by a series of valves which ensure that blood moves in a single direction and prevents backflow. This sequential pumping is coordinated by the heart's electrical conduction system which initiates contractions through cardiomyocytes. This system consists of the sinoatrial node, atrioventricular node, and associated pathways. As the heart pumps, blood is moved throughout the body by the rhythmic movement of smooth muscle in the vessel wall, helping maintain adequate blood pressure and delivery of nutrients to the body's tissues.