Final answer:
The heart's chambers include the atria for receiving blood and the ventricles for pumping blood; the left ventricle pumps blood to the body while valves prevent backflow.
Step-by-step explanation:
The human heart consists of four chambers: two upper atria and two lower ventricles. The atria receive blood and act as receiving chambers, while the ventricles are the primary pumping chambers of the heart. The left ventricle, in particular, pumps oxygenated blood to the systemic circuit, and the right ventricle pumps deoxygenated blood to the lungs. Valves between the atria and ventricles prevent backflow of blood and contribute to unidirectional blood flow, which is crucial for effective circulation.
Moreover, the atria and ventricles work in a coordinated manner to ensure efficient blood flow during the cardiac cycle. Each cardiac cycle consists of a contraction phase (systole) when the ventricles pump blood out of the heart, and a relaxation phase (diastole) when the heart fills with blood. This cycle is regulated by electrical signals originating from the heart's natural pacemaker, the sinoatrial (SA) node.