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27 Cards in this Set
- Front
- Back
What are the embryonic origins of epitheliu,?
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Ectoderm (skin), endoderm (lining of gut), mesoderm (blood vessels and body cavities)
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What are the 2 types of epithelial tissue?
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Surface epithelia that cover surfaces and glands that produce secretions
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What is the basement membrane?
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Thin non-cellular layer consisting of basal almina and lamina reticularis. Functions in support and nutrient exchange
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What are the 2 poles of epithelial cells?
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Apical (faces the lumen) and basolateral (rests against the basement membrane)
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How are surface epithelium classified?
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By number of cell layers between basal lamina and free surface and by morphology of the TOP LAYER (not bottom layers)
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Function and location of simple squamous
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Fluid transport, gas exchange, lubrication. Located in body cavities and lung air spaces.
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Function and location of simple cuboidal
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Ion pumping, secretion, absorption. Cell membranes evident and round centrally located nuclei. Located in ducts, covering of ovary, kidney tubules.
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Function and location of simple columnar
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High volume secretion, transport, absorption, and secretion. Tall and slender with oval nuclei. Located in digestive tract, gallbladder, large ducts, oviducts, uterus, and small bronchi
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Function and location of stratified squamous (non-keratinized)
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Protection and secretion. Top layer flat and contain nuclei, basal layer cuboidal. Located in mouth, epiglottis, esophagus, vagina
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Function and location of stratified squamous (keratinized)
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Only protection, top layer has no nuclei and is non-living and filled with keratin. Located in epidermis.
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Function and location of stratified cuboidal
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Absorption and secretion. No cell boundaries apparent, but round nuclei visible. Located in ducts of sweat glands.
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Function and location of stratified columnar
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Secretion and absorption. These are rare, only found in large excretory ducts, conjunctiva of eye, and male urethra.
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Function and location of pseudostratified
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Secretion, absorption, and lubrication. Nuclei not uniform, and often have cilia. Located in nasal cavity, trachea, bronchi, epididymis
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Function and location of transitional epithelium
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distensible, dome-shaped surface (cobble stone-like). Only found in urinary tract
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What are microvilli composed of?
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25-30 actin filaments cross-linked by villin and fimbrin and anchored into the terminal web.
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What are flagella composed of?
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9 uniformly arranged doublets around a central doublet of microtubules (called an axoneme)
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What are stereocilia?
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They are more like mocrovilli than cilia. They are composed of actin and lack mobility. Found in inner ear and epididymis
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What are the types of basolateral junctions?
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tight junctions, adherens junctions, desmosome junctions, gap junctions, and hemidesmosome junctions
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What function do tight junctions have?
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To join cells and create barrier to intercellular flow. This also prevents movement of basal integral membrane proteins to apical surface (helps maintain polarity)
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What is the function of a gap junction?
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Directly connects the cytoplasm of two cells whcih allows molecules and ions to pass freely from one to the other.
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What is the function of Hemidesmosomes?
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They are a basal surface protein that link epithelia to the basement membrane via integrins.
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What are the 3 modes of exocrine secretion?
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Holocrine (entire cell), merocrine (product released via exocytosis) and apocrine (part of apical cytoplasm released along with product).
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What is a goblet cell?
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Unicellular exocrine gland that secretes mucin via merocrine secretion in the digestive and respiratory tract.
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How are exocrine glands classified?
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By type of duct system (simple vs compound) and by secretory endpiece (tubular, acinar, tubulo-acinar)
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What type of gland is the salivary gland?
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Compound tubulo-acinar exocrine gland that secretes serous and mucous products.
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What are the 2 types of endocrine glands?
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Cord arrangment and follicular arrangement. In cord the hormones are stored in the cells, in follicular they are stored in central follicles.
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What are the 3 mixed glands (endocrine and exocrine)?
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Pancreas, ovary, testes.
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