Capillaries are so small that you can’t see them without a microscope, so for the most you wouldn’t see them anyways! Since capillaries are filled with blood, they are either deep red if they don’t have any oxygen or bright red if they do have oxygen. Capillaries are the main way that all the cells in your body get food and oxygen.

There are about 10 billion capillaries in a human body. Since there are so many capillaries, every cell in the body is at most 2 or 3 cells away from a capillary.