The circulatory system is responsible for delivering oxygen and nutrients to cells.

Here's how it works:

* Heart: The heart pumps blood throughout the body.

* Blood Vessels: Blood travels through arteries, veins, and capillaries.

* Blood: Blood carries oxygen, nutrients, and other important substances to cells.

Oxygen is picked up by the blood in the lungs and transported to cells throughout the body. Nutrients are absorbed from the digestive system and also carried by the blood to cells.