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
