A Level Biology Practice Exam

What does the pulmonary vein do?

1. It carries deoxygenated blood to the lungs

2. It transports oxygenated blood from the lungs to the heart

3. It regulates blood flow returning from the body

4. It carries blood from the right atrium to the aorta

The correct answer is: It transports oxygenated blood from the lungs to the heart

The pulmonary vein plays a crucial role in the circulatory system by transporting oxygenated blood from the lungs back to the heart. This process is essential for delivering oxygen-rich blood to the rest of the body, as it allows the heart to pump this oxygenated blood through the aorta to the systemic circulation. In contrast, other options refer to different functions or parts of the circulatory system. For instance, the pulmonary artery is responsible for carrying deoxygenated blood from the heart to the lungs, and blood returning from the body typically involves veins like the superior and inferior vena cavae, not the pulmonary vein. Additionally, the movement of blood from the right atrium to the aorta is conducted by the right ventricle, not the pulmonary vein.