Circulatory system–animation

Capillary beds throughout every tissue and organ are all parts of one overall system, the circulatory system, and blood is continually pumped through the system by the heart as shown in the following videos:

A common misconception is that a given drop of blood will flow from one organ/tissue in the body to the next in succession before returning to the heart. NOT SO. Note that any given capillary bed is less than a square millimeter in area. Blood entering it comes directly from the heart; blood exiting it goes directly back to the heart.