Your circulatory system contains three blood vessel types: arteries, veins, and capillaries. Arteries carry blood from the heart, unlike veins, which carry blood to the heart. According to the ...

Well, the blood has to be kept moving around all the time because it's the body's delivery system. Every possible part of the body has to be supplied with oxygen and food and water, and the veins and ...

The human heart is a finely-tuned instrument that serves the whole body. It is a muscular organ around the size of a closed fist, and it sits in the chest, slightly to the left of center. The heart ...