How can we identify different epithelial …

SIMPLE

• The cells are extremely thin and flat and form a delicate lining.
• The lining of oesophagus and the mouth are covered with squamous epithelium.

STRATIFIED

• The cells are arranged in many layers to prevent wear and tear.
• Since they are arranged in a pattern of layers, the epithelium is called stratified squamous
• The skin, which protects the body, is made of squamous epithelium.

COLUMNAR

• The columnar (meaning ‘pillar-like’) epithelium facilitates movement across the epithelial barrier.
• It is present where absorption and secretion occur, as in the inner lining of the intestine, tall epithelial cells are present.
• In the respiratory tract, the columnar epithelial tissue also has cilia, which are hair-like projections on the outer surfaces of epithelial cells.
• These cilia can move, and their movement pushes the mucus forward to clear it. This type of epithelium is thus ciliated columnar epithelium.

CUBOIDAL

• Cuboidal epithelium (with cube-shaped cells) forms the lining of kidney tubules and ducts of salivary glands, where it provides mechanical support.
• Epithelial cells often acquire additional specialisation as gland cells, which can secrete substances at the epithelial surface.
• Sometimes a portion of the epithelial tissue folds inward and a multicellular gland is formed.