Heart and blood vessels
The heart is the hardest working muscle in our bodies. A baby’s heart can work harder than an adult’s heart: Up to 190 times a minute versus 60 to 100 times a minute. This rate naturally slows down as your baby grows.
During an average person’s lifetime, the human heart will beat more than 3 million times, pumping about a million barrels of blood.
The cardiovascular system—the heart combined with the blood vessels—is responsible for circulating blood throughout the body. It’s vital to supplying the body with oxygen and nutrients.