List five major functions of epithelium in the body and give examples of cells or organs that provide each function

Epithelium is an animal tissue which can be seen as the covering layer of organs. Functions of epithelium are;

1. Provide protection - Provide protection from radiation, pathogens and mechanical injuries.

Example - Skin

2. Absorption - Absorbs materials.

Example: Inner epithelium of intestine.

3. Secretion - Secret hormones, enzymes, sweat and mucus.

Example: Inner epithelium of small intestine.

4. Exchanging substance - Exchange substance between blood vessels and organs.

Example: Epithelium of lungs

5. Expanding when needed - When it is needed, some epithelium (transitional epithelium) can expand.

Example: Epithelium of bladder