Dr. ANAND SRINIVASAN

 Consists of large number of cells  Classified based on size, shape and functions  Epithelial tissue  Connective tissue  Muscle tissue  Nervous tissue

 Group of tissue that covers the body and lining cavities, hollow organs and tubes.  Functions  Protection  Secretion  Absorption  Cells lie on basement membrane  Less matrix (intercellular substance)

 Simple : single layer of cells  Simple squamous  Simple cuboidal  Simple columnar  Pseudostratified ciliated columnar  Stratified : several layers of cells  Stratified squamous keratinized epithelium  Stratified squamous non keratinized epithelium  Transitional epithelium

 Single layer of flattened cells  E.g. lining epithelium of heart, blood vessels, alveoli of lungs.

 Cube shaped cells lying on a basement membrane  E.g. Proximal convoluted tubule, Thyroid follicle

 Single layer of cells, rectangular in shape, on a basement membrane  E.g. lining epithelium of Stomach, Intestines

 Single layer of cells on basement membrane but has its cell nuclei similar to stratified epithelium  E.g. Trachea

 Composed of number of layers of cells  Superficial layer are squamous  2 types  KERATINIZED ▪ Superficial layer consists of dead epithelial cells that contain a protein ‘KERATIN’ ▪ Found on dry areas ▪ E.g. Skin  NON KERATINIZED ▪ Superficial layer does not contain keratin ▪ Found on wet areas ▪ E.g. Oesophagus, Cornea

 Several layers of pear shaped cells  E.g. Urinary bladder, ureter, urethra