Which is the correct flow of blood through the heart?

Which is the correct flow of blood through the heart?

• A. Right Atrium, Right Ventricle, Pulmonary Veins, Lungs, Pulmonary Arteries, Left Atrium, Left Ventricle, Aorta
• B. Left Atrium, Left Ventricle, Pulmonary Veins, Lungs, Pulmonary Arteries, Right Atrium, Right Ventricle, Aorta
• C. Left Atrium, Left Ventricle, Pulmonary Arteries, Lungs, Pulmonary Veins, Right Atrium, Right Ventricle, Aorta
• D. Right Atrium, Right Ventricle, Pulmonary Arteries, Lungs, Pulmonary Veins, Left Atrium, Left Ventricle, Aorta

Answer: (D)

The flow of blood through the heart follows a one-way circuit: deoxygenated blood returns to the heart, moves from the right side to the lungs for oxygenation, then comes back to the left side to be pumped out to the body. Blood from the body returns to the right atrium, passes through the tricuspid valve into the right ventricle, and is pushed through the pulmonary valve into the pulmonary arteries toward the lungs. In the lungs, blood picks up oxygen and releases carbon dioxide, then returns to the heart via the pulmonary veins into the left atrium. From there it goes through the mitral valve into the left ventricle and is pumped through the aortic valve into the aorta to reach the rest of the body. This sequence matches the order: right atrium, right ventricle, pulmonary arteries, lungs, pulmonary veins, left atrium, left ventricle, aorta. Options that place the pulmonary veins before the lungs, start with the left side, or put the pulmonary arteries after the left ventricle disrupt the correct path of blood flow and oxygenation, so they’re not consistent with how blood travels through the heart and lungs.

The flow of blood through the heart follows a one-way circuit: deoxygenated blood returns to the heart, moves from the right side to the lungs for oxygenation, then comes back to the left side to be pumped out to the body. Blood from the body returns to the right atrium, passes through the tricuspid valve into the right ventricle, and is pushed through the pulmonary valve into the pulmonary arteries toward the lungs. In the lungs, blood picks up oxygen and releases carbon dioxide, then returns to the heart via the pulmonary veins into the left atrium. From there it goes through the mitral valve into the left ventricle and is pumped through the aortic valve into the aorta to reach the rest of the body. This sequence matches the order: right atrium, right ventricle, pulmonary arteries, lungs, pulmonary veins, left atrium, left ventricle, aorta.

Options that place the pulmonary veins before the lungs, start with the left side, or put the pulmonary arteries after the left ventricle disrupt the correct path of blood flow and oxygenation, so they’re not consistent with how blood travels through the heart and lungs.