Capillaries

Tiny, thin-walled blood vessels that allow the exchange of fluid, gases and nutrients between the blood cells. The smallest capillaries are so small that red blood cells must move through them in single file.[1]

## References[edit]

1. ↑ Wile, Dr. Jay L. Exploring Creation With General Science. Anderson: Apologia Educational Ministries, Inc. Capillaries are the smallest blood vessels. 2000