Question

Explain the structure and functions of various types of epithelial tissues.

Answer 1

Epithelial cells are tightly packed cells seen on the external surface of the body, and also line the viscera. It is a continuous layer of cells.

Functions:

1. Provide protection and prevent the entry of germs.
2. In the salivary gland and gastric glands, the epithelial cell is specialized for the purpose of secretion.
3. Epithelium that lines the epidermis will help in the absorption of nutrients from the food.
4. Epithelium in the sweat gland and kidney helps in the removal of waste from the body.

Squamous epithelium

1. Squamous epithelium is made up of flat, irregular cells without intercellular.
2. These epithelia are seen in the inner walls of the esophagus, heart, lungs, and blood vessels.
3. It provides protection for underlying cells from mechanical injury and from pathogens.

Columnar epithelium

1. The columnar epithelium is made up of tall, pillar-like cells which are lengthier than their width.
2. The nucleus is seen towards the base.
3. The columnar cells line the stomach, intestine, and pharynx.

Cuboidal epithelium

1. Cuboidal epithelium is made up of cube-like cells.
2. The nucleus is centrally located.
3. They are seen in thyroid glands, kidney tubules, salivary glands, etc.