Bill Nye the Science Guy (1993)

Episode Overview

Your heart tirelessly circulates blood throughout your body, every moment of every day, ensuring your survival. Roughly the size of your fist, it’s composed of unique muscle known as cardiac muscle. This specialized tissue enables your heart to maintain its rhythm and adjust its pace based on your body's requirements. Functioning as an automatic pump, your heart contracts to push blood through its four chambers and then relaxes. Valves, acting as one-way gates, ensure that blood flows smoothly in a single direction: from the heart to the lungs, back, and then out to the body.