Simple Epithelia | Unilayered Epithelia | Neet Biology | Manish Mevada

Simple squamous epithelium

Structure

Composed of a single layer of flat , tile - polygonal cells . The nuclei of the cells are flattened and often lie at the centre of the cells making a bulge at the cell's surface .

Location

Present in the terminal bronchioles and alveoli , wall of the Bowman's capsules and descending limb of loop of Henle , blood vessels ( endothelium lymph vessels , heart , coelomic cavities mesothelium ) and rete testis .

Function

Protection , excretion , gas exchange and secretion of coelomic fluid .

Simple columnar epithelium

Structure

Elongated cells are placed side by side like column . The outer free surface of each cell is slightly broader . The nuclei are somewhat elongated and lie near the bases of the cells . Certain cells of this epithelium contain mucus and are called goblet ( or mucous ) cells . The epithelium containing mucus secreting cells , along with the underlying supporting connective tissue is called mucosa or mucous membrane .

Location 

Found in the lining of the stomach , intestine, gall bladder and bile duct . It also forms the gastric glands , intestinal glands and pancreatic lobules where it has secretory role and is called glandular epithelium . Intestinal mucosa have microvilli to increase absorptive surface area , it is called brush bordered columnar epithelium .

Function 

Protection , secretion and absorption .

Simple cuboidal epithelium

Structure

Consists of short , cube - shaped cells.

Nuclei are located in the centre of the cell . The cells of cuboidal epithelium often form microvilli on their free surface which increase absorptive surface area . It gives a brush - like appearance hence called brush bordered cuboidal epithelium .

Location 

Present in the small salivary and pancreatic ducts , thyroid follicles , parts of membranous labyrinth , proximal and distal convoluted tubules of the nephrons of kidneys , ovaries , seminiferous tubules ciliary bodies , choroid and iris of eyes sweat glands , etc.

Function 

Protection , secretion , absorption , excretion and gamete formation .

Manish Mevada

M.Sc, M.Phil, B.Ed