A normal child's heart beat is 100 to 120 beats in a minute. An adult human heart pumps about six quarts of blood through the body. Our heart is a muscle about the size of our fist. Arteries carry blood away from our heart. Veins carry blood to our heart.
Capillaries are our smallest blood vessels.
Our heart rate is the number of beats in one minute. The left and right atriums of our heart are the top chambers. The heart cannot use its own blood to nourish its own muscle. The nervous system regulates the heart and other parts of the circulatory system. The sound we hear when we listen to our heart beating is the sound made by the valves closing.