Let’s follow the blood on a simple loop through the circulatory system to see how it works: Atherosclerosis can gradually make the arteries narrower, affecting the amount of blood that can flow ...

Reference Article: Facts about the human ... circulatory system and pumps blood through the rest of the network. This hollow muscle is made up of four chambers: The left and right atriums make ...

We refer to an integrated unit as an organ system. Groups of organ systems work together to make complete, functional organisms, like us! There are 11 major organ systems in the human body.