A ventricle is one of the two lower chambers of the heart that pump blood out to your body. Your heart has four chambers total: two smaller upper chambers called atria that receive blood, and two larger, more muscular lower chambers, the ventricles, that do the heavy lifting of pushing blood where it needs to go.

The right ventricle pumps blood to your lungs to pick up oxygen, while the left ventricle, the strongest chamber of all, pumps oxygen-rich blood out to every part of your body, from your brain down to your toes. Every time your heart beats, you're feeling your ventricles contract and squeeze blood out through your arteries.

You can remember which chambers are the ventricles because they're on the bottom of the heart, and they do the vigorous work of pumping blood throughout your entire circulatory system. Without properly functioning ventricles, your body wouldn't get the oxygen and nutrients it needs to keep you running, thinking, and playing.