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