Which job does the circulatory system do?
It brings oxygen to cells. It breaks down food into small pieces.
To stay alive, animal cells must get water and oxygen. Animal cells also produce carbon dioxide, a waste that must be removed. An animal's respiratory and circulatory systems work together to do these jobs.
An animal's respiratory system is made up of organs that work together to bring in oxygen gas from the environment. The respiratory system also removes carbon dioxide gas from the animal's body. Some animals have lungs to exchange oxygen and carbon dioxide with the air. Other animals have gills to exchange oxygen and carbon dioxide with water.
An animal's circulatory system is made up of organs that work together to move blood through its body. The heart pumps blood through blood vessels throughout the body. As blood moves through blood vessels, it delivers oxygen, nutrients from food, and water to cells. Blood also absorbs waste, including carbon dioxide. When the blood is pumped into the lungs or gills, it releases carbon dioxide and absorbs oxygen.
The circulatory system brings oxygen, nutrients, and water to cells. It also helps remove carbon dioxide waste.
The circulatory system does not break down food into small pieces. This job is done by the digestive system. After the digestive system breaks down food, blood vessels in the intestines absorb the nutrients from the food. The blood then carries the nutrients to cells throughout the body.