Cells need oxygen to make energy. oxygen-rich blood is transported to tissues. when the oxygen is dropped off, it needs to move through structures that are small and thin. which vessels allow for oxygen movement into the tissues? arteries veins heart capillaries

capillaries

Capillaries are the small and thin blood vessels which are 5 to 10 micrometers in diameter. Through capillaries the exchange of gases like carbon dioxide, oxygen, nutrients and waste takes place at the capillary. It supplies oxygenated blood to all the parts of the body and takes away the deoxygenated blood towards the heart so that it can be expelled out of the body.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint