Circulatory system
The circulatory system delivers oxygen and nutrients to cells and takes away wastes.
The heart pumps oxygenated and deoxygenated blood on different sides.
The types of blood vessels include arteries, capillaries and veins.
Capillaries are small, thin blood vessels that connect the arteries and the veins. Their thin walls allow oxygen, nutrients, carbon dioxide and waste products to pass to and from the tissue cells