Veins carry about 70% of the total blood volume in the body at any given time. This is because veins are larger and more numerous than arteries, and they have a lower pressure system. Veins also contain valves that help to prevent blood from flowing backward, which helps to keep the blood flowing towards the heart.
Here are some additional details about veins:
- Veins carry blood back to the heart.
- Most veins carry deoxygenated blood (blood that has delivered oxygen to the body's tissues and is returning to the lungs to be re-oxygenated). The exception to this is the pulmonary veins, which carry oxygenated blood from the lungs to the heart.
- Veins have thinner walls than arteries.
- Veins are usually located closer to the surface of the skin than arteries.
Understanding the role of veins in blood circulation is important for maintaining good health. By keeping the blood flowing smoothly through the veins, we can reduce the risk of developing blood clots and other circulatory problems.
