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45 Cards in this Set
- Front
- Back
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5 main functions of epithelium?
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Protection-stratified(skin)
Absorption- single or simple(intestines) secretion - form glands sensation- taste buds contraction- myoepithelial cells |
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where does Epithelium get is nutrients and blood?
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Underlying CT
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basal Lamina
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Separates basal cells from CT
all have intercellular junctions or specializations Gives cells polarity |
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what three things make up the BL
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Collagen type IV, laminin, and fibronectin
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what composes the Basement Membrane
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Could be 2 BL
usually BL with underlying reticular lamina |
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specialization of apical membrane?
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Microvilli, cilia, and sterocilia (male reporductive tract)
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what characterizes the lateral domain?
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intercellular junction
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desmosomes ( macula adherens)
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spot weld to hold cells together
have intermideiate filaments Abundant where epithelium is exposed to stress (skin) |
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hemidesmosome
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attaches cell to Basement membrane
also abundant with physical stress |
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autoimmune blistering disease (bullous pemphigoid)
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Antibodies attack proteins assoc with hemidesmosomes and causes blisters (detaching of basement membrane)
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Gap junctions
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connect adjacent cells, communication
characterized by open channels (connexons) ions and other small particles |
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terminal bar
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made of Zonula occludens
Zonula adherans macula adherans (Desmosomes) |
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Zonula occludens
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make pentalaminar structure
surrounds cell and prevents diffus |
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Zonula adherans
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wraps around cells
holds cells together actin microfilaments |
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Clostridum perfringes
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entertoxin attack ZO and allows fluid to move through intercellular space causes dehydration
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Microvilli
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Specialized for absorption
core of actin anchored to a web or micro/intermediate filaments called terminal web |
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Cilia (longer than Microvilli)
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cytoskeleton made of 9 doublets and central pair of microtubules (9+2)
arms are made dynein |
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Kartegener's syndrome
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absence of dynein
respiratory infections inmotile sperm female can get pregnant but mainly due to peristalsis |
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Stereocilia
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only in male reproductive tract
not involved in movement deflection causes membrane potential epididymis and inner ear |
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simple and stratified cells
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single cell layers, multiple cells layers
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transitional cells
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only in urinary tract
characterized by DOME SHAPED CELLS |
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psuedostratified
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looks like more than one layer but actually a single layers (columnar and cuboidal mixed)
trachea |
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cell shape
squamous cuboidal columnar |
flattened
height = width height> width |
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Ex of simple squamous
simple cuboidal simple columnar |
endothelial cells
ducts/tubules of kidney duodenal epithelial cells(intestines |
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Stratified squamous non kerantinized
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protective function
esophagus and vagina(upper cells are flattened) |
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Strat. squamous keratinized
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skin, prevents water loss
upper cells are dead and have no nuclei |
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Exocrine glands
endocrine glands |
duct system
bloodstream (hormones) |
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three types of secretion
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Holocrine
Apocrine Merocrine |
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holocrine
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entire cell filled with secretory product, cell is shed (sebaceous and tarsal)
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apocrine
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apical ends filled then that part is realeased (mammory glands)
Vesicles |
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Merocrine
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secretory cells formed, go to apical end and exocytosis (pancreas)
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Ex of simple tubular gland
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colon
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ex of coiled tubular glands
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sweat glands of skin
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ex of compound acinar gland
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mucous gland from larynx
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dysplasia
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change in size of cells (precancerous)
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hyperplasia
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increased number of cells (high altitude and greater red blood cells)
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hypertrophy
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enlarged cells
pysiological (puberty) or steroids increased muscle demands |
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hypoplasia
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decreased number of cells
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hypotrophy
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atrophy
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pleomorphism
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many sizes and shapes
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anaplasia
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dedifferentiation
old cells stay the same but new ones are less differentiated than old ones |
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metaplasia
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change in cell type as a result of physical or chemical stress (simple ---> stratified)
acid reflux causes cell to become gastric like and secrete mucous to protect cells (Barrets Epithelium) |
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papilloma
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benign tumor from surface epithelium
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adenoma
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benign tumor from glandualr epithelium
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Factor affecting malignant tumors
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anaplasia
mitotic activity metastases invasion |
