College of Massage Therapists of British Columbia (CMTBC) Practice Exam

How do the pulmonary veins function in the circulatory system?

1. They carry deoxygenated blood to the lungs

2. They bring oxygenated blood back to the left atrium

3. They transport blood from the heart to the body

4. They deliver blood from the aorta to the lungs

The correct answer is: They bring oxygenated blood back to the left atrium

The pulmonary veins play a crucial role in the circulatory system by bringing oxygenated blood back to the left atrium of the heart. After blood has been oxygenated in the lungs—where carbon dioxide is exchanged for oxygen—the pulmonary veins collect this oxygen-rich blood and transport it to the heart. This is essential for the efficient circulation of oxygenated blood throughout the body, ensuring that tissues and organs receive the oxygen necessary for cellular respiration and overall function. In contrast to the pulmonary veins, other structures in the circulatory system have different roles. For instance, deoxygenated blood is carried to the lungs via the pulmonary arteries, not the veins. Additionally, arteries such as the aorta are responsible for carrying oxygenated blood from the heart to the rest of the body, while the pulmonary veins specifically function to return the oxygenated blood from the lungs to the heart, completing the pulmonary circuit. Thus, the correct answer highlights the fundamental role of the pulmonary veins in facilitating the flow of oxygenated blood back to the heart.