Nursing Entrance Exam (NEX) 2025 – 400 Free Practice Questions to Pass the Exam

The sequence of blood flow through the human heart and lungs starts in the right atrium, moves to the right ventricle, from there it is pumped to the lungs for oxygenation, and then returns to the left atrium. After that, blood flows into the left ventricle before being distributed throughout the body.

Beginning with the right atrium, deoxygenated blood enters from the body. It then travels to the right ventricle, which pumps it to the lungs through the pulmonary arteries. In the lungs, carbon dioxide is removed, and oxygen is taken up by the blood. The newly oxygenated blood then returns to the heart, entering through the left atrium. Following that, blood flows into the left ventricle, which pumps oxygen-rich blood out to the rest of the body through the aorta.

This pathway illustrates the importance of the right side of the heart being responsible for pulmonary circulation (to the lungs) and the left side managing systemic circulation (to the body). Understanding this sequence is critical, as it reflects the function of the heart in maintaining efficient blood flow and oxygen delivery in the body.