Term
| what are the 5 functions of epithelium? |
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Definition
| protection, absorption, secretion, sensation, contraction |
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Term
| protective epithelium are typically what type of epithelia? |
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Definition
| stratified or multilayered; ex: epidermis of the skin, lining of esophagus |
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Term
| absorptive epithelia are typically what type of epithelia? |
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Definition
| simple or single layered and have surface specializations to increase the absorptive surface area; ex: intestinal epithelium |
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Term
| True or False: all glands form from epithelia? |
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Definition
|
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Term
| what do acini do to glands? |
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Definition
| squeeze glands to allow release of product |
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Term
| what are myoepithelial cells? |
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Definition
| specialized epithelial cells found in the acini of glands, these cells help to squeeze the secretory product from the gland |
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Term
| basal lamina is formed by what type of cells? |
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Definition
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Term
| what are some basic characteristics of epithelium? |
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Definition
| avascular, cells are tightly packed, epithelial tissues form coverings or linings of organs and form glands, all epithelial tissues have a basal lamina, all epithelial tissues are characterized by intercellular junctions or specializations |
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Term
| What forms the reticular lamina? |
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Definition
|
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Term
| what are the 3 major components of the basal lamina? |
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Definition
| COLLAGEN TYPE IV, laminin, fibronectin |
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Term
| what is the basal lamina? |
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Definition
| structural layer that underlies epithelia; can serve as a filter, serves to organize tissues, separates epithelia from the underlying connective tissue, attachment to basal lamina gives epithelial cells polarity |
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Term
| True or False: Basal lamina serve a role in tissue migration during development. |
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Definition
|
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Term
| The reticular lamina is what collagen type? |
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Definition
|
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Term
| what is the basement membrane? |
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Definition
| may be 2 basal laminae together as in the renal glomerulus; more often, it is a basal lamina with an underlying reticular lamina |
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Term
| anchoring fibrils in the basement membrane are what collagen type? |
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Definition
|
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Term
| what are some specializations of the apical domain? |
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Definition
| microvilli, cilia, stereocilia |
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Term
| what are characteristic of the lateral domain? |
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Definition
|
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Term
| how is polarity induced in the epithelial cells? |
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Definition
| by interactions with basal lamina and underlying connective tissue; concentration gradients |
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Term
| True or False: all epithelial tissues are characterized by intercellular junctions or specializations. |
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Definition
|
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Term
| what is a desmosome (macula adherens)? |
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Definition
| patch like connection between adjacent cells; serves to hold the cells tightly together; have intermediate filaments associated with them; particularly abundant in epithelia that are exposed to physical stress |
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Term
| what does it mean when a tissue has many desmosomes? |
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Definition
| that tissue undergoes a lot of force |
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Term
| What are the intermediate filaments made up of in desmosomes? |
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Definition
|
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Term
| what type of cells make desmosomes? |
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Definition
|
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Term
| what is the function of a hemidesmosome? |
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Definition
| attaches basal cells to the basement membrane; prominent in epithelia exposed to physical forces as experienced by epidermis |
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Term
| what is the name of the disease in which antibodies attach to certain proteins associated with hemidesmosomes causing them to detach from the underlying basement membrane? |
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Definition
| Bullous pemphigoid; causes blisters |
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Term
| what are gap junctions (nexus junctions)? |
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Definition
| allows cells to communicate electrically, ions and small particles can pass through (smaller than 1500 daltons), these communications become important in tissues that have to function all together (ex: heart), composed of connexons |
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Term
| what does the terminal bar join? |
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Definition
|
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Term
| True or False: the terminal bar goes all the way around the apex of the cell |
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Definition
|
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Term
| what are the 3 junctions that compose the terminal bar? |
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Definition
| tight junctions (zonula occludens), zonula adherens and macula adherens |
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Term
| True or False: There is some actin in the terminal bar |
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Definition
|
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Term
| What is the function of the tight junction? |
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Definition
| allows for regulation by the cell, prevents paracellular route, completely surrounds the cell like a belt or a band |
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Term
| what is the function of the zonula adherens? |
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Definition
| functions to hold adjacent cells together, had actin microfilaments associated with it, has morphological similarities to the desmosome in action |
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Term
| what is the function of the junctional complex? |
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Definition
| prevents materials from passing between cells via the intercellular route |
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Term
| the enterotoxin made by C. perfringens attacks what part of the epithelium to cause intense diarrhea and abdominal pain? |
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Definition
| the zonula occludens (tight junctions) |
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Term
| what are microvilli specialized for? |
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Definition
|
|
Term
| what is the core of microvilli consist of? |
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Definition
|
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Term
| where can microvilli be found in the body? |
|
Definition
| the kidney and small intestine |
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|
Term
| what are cilia made up of? |
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Definition
| a cytoskeleton made up of nine doublets of microtubules and a central pair of microtubules |
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|
Term
| what is the function of cilia? |
|
Definition
| movement; tracheal cilia move mucous toward the pharynx |
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Term
| which is longer: microvilli or cilia? |
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Definition
|
|
Term
| True or False: All cilia have a basal body associated with them |
|
Definition
|
|
Term
|
Definition
| an ATPase which functions as a motor for ciliary movement |
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|
Term
| what is the clinical term a case in which an individual has an absence of dynein and suffers from frequent respiratory infections? |
|
Definition
|
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Term
|
Definition
| sensory type structures with very long cellular processes; not involved in movement; their deflection causes changes in membrane potential; internal structure similar to microvillus |
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Term
| where are stereocilia found? |
|
Definition
| found ONLY in the epididymis and the inner ear |
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|
Term
| what does it mean for an epithelium to be keratinized? |
|
Definition
|
|
Term
|
Definition
| single celled glands (secretion) |
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Term
| True or False: In pseudostratified ciliated, all the cells rest on the basal lamina. |
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Definition
|
|
Term
| what is a transitional epithelium? |
|
Definition
| an epithelium that adapts to distension of the urinary tract; characterized by dome-shaped cells |
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|
Term
| what are the 2 major types of glands? |
|
Definition
|
|
Term
| True or False: all glands develop as ingrowths of epithelial cells into the underlying connective tissue |
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Definition
|
|
Term
| What are the 3 mode of secretion for exocrine glands? |
|
Definition
| holocrine, apocrine, merocrine |
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|
Term
| what happens during holocrine secretion? |
|
Definition
| the entire cell fills with secretory product and then the cell is shed- sebasceous and tarsal glands; they undergo apoptotic death and release all their product |
|
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Term
| what happens during apocrine secretion? |
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Definition
| the apical end of the cell is filled with secretory product and that part of the cell is released; ex: mammary glands; apocrine is very large secretory granules are released. Note: the entire apex does not break off |
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|
Term
| what happens during merocrine (eccrine) secretion? |
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Definition
| secretory cells are formed, accumulated near the apical end of the cell and are released by exocytosis; ex: pancreatic acinar cells |
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Term
| True or False: Several goblet cells are present at the Crypt of Lieberkuhn (intestinal gland in the colon) |
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Definition
|
|
Term
|
Definition
| changes in size, shape or organization of cells (can be precancerous) |
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Term
|
Definition
| increased number of cells; for example: increased number of erythrocytes at a high altitude |
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Term
|
Definition
|
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Term
|
Definition
| decreased number of cells |
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|
Term
| what is hypotrophy (atrophy)? |
|
Definition
| cells smaller than normal; if the nerve to a muscle is severed the muscle cells atrophy |
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Term
|
Definition
| many different sizes and shapes of cells |
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Term
|
Definition
| new cells change to a different cell type than the existing cells |
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Term
|
Definition
| existing cells change to a different cell type |
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|
Term
| what is a benign papilloma? |
|
Definition
| benign tumor arising from a surface epithelium |
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|
Term
| what is a benign adenoma? |
|
Definition
| a benign tumor arising from a glandular epithelium |
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|
Term
| what are the factors that affect malignancy of a tumor? |
|
Definition
| anaplasia, mitotic activity, invasion, metastases |
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|
Term
| what is an adenocarcinoma? |
|
Definition
| a carcinoma arising from glandular tissue |
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