List functions of Epithelial cell
Protects, lines, covers, filters biochemical substances, absorbs nutrients, provides sensory input, manufactures secretions and excretions
List common characteristics
polar, have lateral surfaces, lack blood vessels and capillaries, most are innervated
Apical Surface
side that faces lumen or body cavity
Basal surface
side of cell that faces underlying connective tissue
Tight Junction
formed by fusion of outer layers of plasma membrane of adjoining cells, found where there can be no leaks, like bladder and digestive tract
Desmosomes
strong welded plaque which connects walls, has filaments like velcro, tonofilaments extend anchor lines. found in tissue that stretches like skin and hair, uterus
Gap junctions
linked by tube channels, connexons cytoplasm to cytoplasm, allows passage, found in intestine, heart, smooth muscle tissue
Basement membrane
non living meshwork of fibers that cements to connective tissue
E. cells classified by
number of layer of cells, shape of cells, prescence of surface specialization
Simple squamous cell
delicate and thin, found in lining surfaces involved in passage of gas/liquid, fragile, lung/kidneys, mesothelium and endothelium
Simple cuboidal cell
single layer cube cell, sheltered areas where secretion/absorption, important in endocrine and exocrine tissue. found in thyroid liver lining, pancreas, kidney, salivary gland
Simple columnar cell
single layer, elongated and packed, nucleai aligned near basement, line gastro from stomach to rectum, secretion/absorption
Absorptive cell
Apical surface blanketed by microvilli
Goblet cell
wineglass shape, make and stores lubricating mucus
Stratified Squamous
Various cell layers, areas subject to mechanical and chemical stress; lining of mouth, esophasgus, vagina, rectum, outer layer continuously worn away, cuboidal at basement pushed up
Stratified Cuboidal
generally only 2 layers, found mainly along large excretory ducts; sweat, mammory, and salivary glands, importnat in protecting delicate deeper layers of
Stratified columnar epithelium
rare, only found in select parts of respiratory, digestive, and reproductive systems
Pseudostratified columnar epithelium
single layer, appears multi, found in respiratory, portions of male reporductive
immunoglobulins
disease fighting molecules in mucus of respiratory tract
Transitional e cell
ability to stretch, leak proof membrane, found in bladder, ureters, ureatha, calyxes of kidney