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34 Cards in this Set
- Front
- Back
Epithelial Tissue |
- covers or lines every body surface and all body cavities |
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Characteristics of Epithelial Tissue |
- composed entirely of cells - polarity: ezposed to external surface or interanl body cavity - the basal surface of epithelial tissue is bound to a thin basement membrane - avasculairty: lack blood vessels obrains nutrients directly acroos apical sufcae of by difussion thorugh basal layer - richly innervated - highly regerneration capacity |
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Functions |
- physical proteciton - Selecive permeability - secretion - sensations |
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Basement Membrane |
- three layer between epithelial and connective tissue - two laminae: closest to epithelium contain collagen fibers recticular lamina: cells underlying connective tissue |
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Basement Membrane Functions |
- Physical support for epithelium - anchoring epithelium to connective tissue - barrier that regulates moelcule between epithelium and connective tissue |
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Intercellular Junctions |
- specialized connections in the plasma membrane of their lateral surfaces - four types of junctions |
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Tight Junctions |
- encircles epithelial cells near their apical surface and compleltely attaches eahc cell together |
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Adhering Junctions |
- formed completely around the cell type of support for the cell provides the only means of junctional support for the aprical surface |
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Desmososes |
- a button or snap between adjacent epithelial cells - holds cells together only at stress points |
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Gap Junctions |
- across intercellular hap between neighbor cells |
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Simple Epithelium |
one cell layer thick and in direct contact with basement cell - apical surface is often covered by mucus to prevent form friction - found where primary function is filtration, absorption, or secretion |
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Stratified Epithelium |
- two or more layers of epithelium cells - found where areas are subjected to stress or abrasive actvities |
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Squamos Cells |
- are flat, wide, irregular in shape - nuclesu is flattened disk |
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Cubodial Cells |
- tall as they are wide - nucleus is oval - located in bassal layer region |
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Transitional Cells |
- change thier shape depending how stretched epithelial tissue becomes |
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Simple squamos epithelial |
- single layer of flattened cells - extremely delicated and highly specialized to allwo rapid movement of moelcules across the surface - only found in protected regions where moist surfaces reduce friction |
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Simple Cubodial Epithelium |
- fucntions pirmarily to absorb fluids and other subtances across apical membrane |
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Simple Columnar Epithelium |
- has two forms with cilia and with out - noncilitated: absorption and secretion of mucin - Ciliated: Mucus covers the surface, secretion of msucin by action of cilia |
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Stratified Squamos Epithelium |
- exists in two forms: nonkeratinized and keratinized - nonkeratinized: remian alive all the way to apical suface and kept moist Keratinized: apical surface is composed of cells that are dead/lack nucei and/or organelles |
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Stratified Cubodial Epithelium |
- function is mainly protective, its strengthens wall of gland ducts |
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Stratified Columnar Epithelium |
- found in large ducts of salivary glands |
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Pseudostrafied Columnar Epithelium |
- found in two forms: ciliated and nonciliated - ciliated: secrete mucins - nonciliated: no goblet cells |
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Transitional Epithelium |
- handful presense of binucleated cells |
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Glands |
- individual cells or mulitcellular organs compsoed mostly of epithelial cells |
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Endocrine Cells |
- secrete products directly into the blood stream |
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Exocrine Glands |
- maintain contact with epithelial surface by meand of a duct |
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Simple Gland |
- have single branched ducts |
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Compound Glands |
- exhbit branched ducts |
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Serous Glands |
- produce watery fluid like sweat, milk, tears |
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Muccus Glands |
- secret mucin which forms mucus when mixed with water |
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Mixed Gland |
- contain both serous and mucous cells |
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Merocrine Glands |
- package secertion in secretory vesciles and travel to apical surface and release by exocytosis |
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Holocrine Glands |
- cell accumulates a product then disintegrats |
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Aprocrine Glands |
- cells acculate thier secreoty product within apical proitonof thier cytoplasm |