epithelium
/ˌɛpɪˈθiliəm/
noun
- The thin layer of tissue that covers the surface of the body, lines internal organs, and forms glands.
- Damage to the epithelium in the lungs can make breathing difficult.
- The stomach's epithelium secretes digestive juices to help break down food.
- The epithelium of the skin protects the body from germs and injury.