Dive Master Practice Exam

Blood vessels that carry blood towards the heart are known as veins. Veins play a critical role in the circulatory system by returning deoxygenated blood from the various parts of the body back to the heart. They are equipped with one-way valves that prevent the backflow of blood, ensuring it moves efficiently in the direction of the heart.

Veins have thinner walls compared to arteries, as they do not need to withstand high pressure from the blood being pumped directly from the heart. The structure of veins allows them to be more flexible and accommodate varying volumes of blood as they transport it back to the heart.

In contrast, arteries carry blood away from the heart, delivering oxygenated blood to the body's tissues. Capillaries are microscopic vessels where the exchange of oxygen, carbon dioxide, and nutrients occurs between blood and tissues, while venules are small vessels that collect blood from capillaries and drain into larger veins. Understanding the specific roles of these different types of blood vessels is essential for comprehending the overall function of the circulatory system.