Epithelial Cells.docx

Epithelial Cells ‘Lining cells’ Haematoxylin – stains nucleus (negatively charged things) Endothelial – ‘not on surface’ All epithelial cells are supported by basement membrane which separates epithelial from underlying supporting tissue “Simple” epithelial = 1 type “Stratified” epithelial = More th...

Epithelial Cells ‘Lining cells’ Haematoxylin – stains nucleus (negatively charged things) Endothelial – ‘not on surface’ All epithelial cells are supported by basement membrane which separates epithelial from underlying supporting tissue “Simple” epithelial = 1 type “Stratified” epithelial = More than 1 type Squamous Slightly irregular shape, small centrally located nucleus and can be stratified into layers. Cuboidal Cubic shape, Secretory epithelial, typically have lumen crossing them Columnar long column-like shape, Absorptive Pseudostratified Usually looks like multiple cells but this is not the case it is one type of cell e.g. respiratory tract where goblet cells are present Special Functions Finger-like projections; Cilia (movement), Microvilli (absorption), Stereocilia (sense) Secretory; Mucous, Enzyme, Hormone Glands Tubular – intestine and uterine glands Coiled – sweat glands Compounds – pyloric glands Secretion Merocrine – Vesicles fuse with cell surface membrane to secrete product of the gland Apocrine – Part of the cell is pinched of (with the glands) to release product Holocrine – mature cell dies to secrete product Exocrine Glands – Release contents onto epithelial surface either directly or via duct Endocrine Glands – have no duct system, but release contents into bloodstream to act on distant tissues.