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 ...

Reference Article: Facts about the human circulatory system. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. The circulatory system, also known ...

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 ...