Final answer:
The pathway of blood through the heart starts at the right atrium, flows to the right ventricle and then to the lungs for oxygenation. It returns to the left atrium, moves to the left ventricle, and is then pumped to the rest of the body via the aorta.
Step-by-step explanation:
The pathway of blood through the heart begins when deoxygenated blood enters the right atrium from the body via the superior and inferior vena cava. The blood then flows into the right ventricle, which pumps it to the lungs through the pulmonary artery for oxygenation. After receiving oxygen, the blood returns to the heart's left atrium via the pulmonary veins. It is then sent to the left ventricle, the chamber of the heart responsible for pumping oxygenated blood out through the aorta to the entire body. Four valves within the heart ensure that blood flows in the correct direction, preventing backflow and maintaining efficient circulation. These include the tricuspid, pulmonary, mitral, and aortic valves, corresponding to their respective locations between chambers and vessels.