BIOL 2021 Lecture Notes - Lecture 3: Mast Cell, Chondroblast, Lamina Propria
15 Apr 2016
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Document Summary
Tissue: functionally related cells that come together to perform a related function. Epithelial tissues either covers a body surface or lines a cavity. It affords protections, filtration, ion transport, excretion, secretion. Epithelium is unique because it is cellular (densely packed with cells), uses specialized contacts (allowing cells to communicate and anchor), exhibits polarity (differences in regions: apical surface- top, basal-bottom) Supported by connective tissues (if there"s epithelial tissues, there"s connective, always) Epithelial tissue is without blood supply (avascular), but it is innervated. Stratified (more than one layer) (used for protection) Endothelium: lining of hollow circulatory system organs. Mesothelium: covers visceral organs and secretes serous fluid. Keratinized: (contains keratin which makes it waterproof). Features dead and dry cells at surface because they are too far from blood supply. Nonkeratinized: (moist lining of body openings, such as the mouth) Epithelium can stretch and descend (changes in shape and size) Empty bladder looks like stratified cuboidal: full bladder epithelial tissue looks more flat.
