Question

The protein present in the stratified epithelium of skin, hairs and nails is____________

• A. Keratin
• B. Rhodopsin
• C. Iodopsin
• D. Retinol

Answer 1

The correct option is A

Keratin

Simple epithelial cells can be derived from all the three germinal layers like Epidermis,Endodermis and Mesoderm.The cells in this tissue are very closely packed with very less intercellular spaces and have a free surface on the other side. Basing on the number of layers and modifications they show, Epithelial tissues are further divided into two major categories a). Simple Epithelium & b). Stratified Epithelium.
When we observe stratified epithelial cells it is nothing so specific to differentiate from simple epithelium but the number of layers will increase to make it much more thick,has a defined function.The cells of the basal layer in this tissue continuously undergoes mitotic divisions so as to replace the worn out cells.Basing on the number of layers and shapes of cells it is again divided into a)Transitional epithelium b)Stratified Squamous epithelium c)Columnar stratified cells
Most common type of stratified epithelium,it is multi layered but top layer of it is of Squamous type, that is cells are broad and irregular. It is present at areas where more wear and tear is seen for example in Skin,Buccal cavity,Pharynx,Oesophagus ​​​​​​.Keratinized stratified squamous epithelium is found only in the skin, hair and nails.