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