Term
| Types of Epithelial Cells |
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Definition
Simple epithelia:
Simple Squamous - endo/mesothelium
Simple Cuboidal
Simple Columnar
Stratified Epithelia:
Squamous, Cuboidal and Columnar
Pseudostratified Epithelium
Transitional Epithelium (urothelium)
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Term
Simple Squamous Epithelium Characteristics
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Definition
Function: rapid exhange of substances btw blood and tissue
Endothelium:
inner lining of blood vessels
1 layer of cells
Mesothelium:
covers peritoneum, pleura and pericardium |
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Term
Simple Cuboidal Epithelium
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Definition
- Located in inner lining of kidney tubules and thyroid follicles
- Highly polarized: Partic. in absorption, secretion (thyroid gland) and active ion transport (kidneys)
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Term
Simple Columnar Epithelium
- Where is the nucleus of the cell?
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Definition
- Located in small intestine lining
- Nucleus in middle portion of cell
- Apical Domain has microvilli -> Brush border
- absorption of proteins, sugar and lipids which are rel. at basolateral domain into blood circ.
- then trans. to liver
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Term
Stratified Squamous Epithelium w/ Moderate Keratin (Nonkeratinized)
- What does it consist of?
- Where is it located?
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Definition
- Consists of undiff. basal cells spec. for mitotic division
- Stratified cells covering basal layer are differentiating cells
- Cells of outer layer are highly differentiated (increase keratin content to protect tissue
- Outermost cells retain nuclei
- Cornea, Oral Cavity, Anal Canal, Esophagus, Vagina, Internal Portion of Lips
- Must be kept moist to keep from dying/drying out
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Term
Stratified Squamous Epithelium w/ abundant keratin (Keratinizing)
- What does it consist of?
- Where is it located?
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Definition
- Consists of undiff. basal cells spec. for mitotic division
- Stratified cells covering basal layer are differentiating cells
- Outer layer contain abundant keratin to prev. H2O loss and penetration of chem/physical insults
- protected from abrasion by keratin
- kept hydrated and protected from dehydration by glycolipids produced in the stratum granulosum
- Found in skin, tongue and external portion of lips
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Term
Pseudostratified Columnar Ciliated Epithelium
- What types of cells does it consist of?
- Where is it found?
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Definition
- 3 Major Cell Types:
- Columnar cells w/ cilia
- Basal cells anchored to basal lamina
- Goblet Cells (mucus-secreting)
- Columnar and Goblet cells reach from basal lamina to lumen
- Found in the trachea and upper respiratory tract
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Term
Pseudostratified Columnar Epithelium with stereocilia
- What cell types does it contain?
- Where is it located?
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Definition
- Contains:
- Principal Cells (Columnar cells w/ stereocilia and highly dev. Golgi Apparatus-near apical side)
- Basal cells
- Both assoc. w/ basal lamina
- Found in epydidymis
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Term
Transitional Epithelium
- What cell types does it consist of?
- Where is it found?
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Definition
- Consists of:
- Dome-shaped columnar cells (basal lamina to lumen)
- Basal cells
- Superficial cells respond to tensional forces (caused by urine)
- Plaques of aggregated proteins are found on apical plasma mem. of columnar cells
- Found in urinary bladder, ureters, superior urethra and gland ducts of prostate
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Term
Stratified Cuboidal Epithelium
Characteristics |
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Definition
Rare type of epithelial tissue composed of cuboidally shaped cells arranged in multiple layers.
They protect areas such as ducts of sweat glands, mammary glands, and salivary glands. |
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Term
Stratified Columnar Epithelium
Where is it found?
What is its function? |
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Definition
- Found in the ocular conjunctiva of the eye, in parts of the pharynx and anus, the female's uterus, the maleurethra and vas deferens. Also in intralobular ducts in salivary glands.
- The cells function in secretion and protection.
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Term
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Definition
| Mesothelium seen as if looking down on a surface view to see "pavement" effect of the lining cells. Silver stains the intercellular cement dark between adjacent cells. Notice how corrugated the cell membranes are. Mesothelium = the simple squamous epithelium lining body cavities and mesenteries. |
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Term
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Definition
| High power view of endothelial cells lining a small blood vessel cut in cross-section. (You see just the nuclei - the cytoplasm between them is extremely flat.) Endothelium = the simple squamous epithelium lining blood vessels. |
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Term
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Definition
| Low power view of larger vessels, showing endothelial nuclei lining the lumen. The yellowish cells filling each vessel's lumen are blood cells. |
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Term
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Definition
Simple cuboidal epithelium lining a tubule (longitudinal cut). Some of the cell boundaries between "blocks" or "cubes" here are quite distinct.
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Term
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Definition
| Simple cuboidal epithelium in Mallory stain (longitudinal cut). Note the dark chromatin clumps in the nuclei. Underneath the epithelium lies a small blood vessel filled with orange-colored blood cells. |
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Term
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Definition
| Cross-section of tubules. The smaller ones clustered in the center and upper left are lined by simple squamous epithelium. The larger pink tubules have simple cuboidal epithelium. |
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Term
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Definition
| A tubule stained to show the pink basement membrane underlying the base of the simple cuboidal epithelium. Stained with periodic acid Schiff reagent (PAS), which stains mucopolysaccharides. |
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Term
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Definition
| Simple columnar epithelium with very regular line-up of nuclei. |
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Term
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Definition
| Simple columnar cells cut tangentially to show how they form a very regular "pavement" when viewed from the surface. The cells are like tall blocks arranged very closely to each other with a small amount of tissue fluid in between. |
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Term
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Definition
| EM of cells with striated border. Notice the evenness and regularity of the microvilli. This is an adaptation of the cell surface for absorption. Notice also the corrugation of the cell boundaries as they fit next to each other. 1= nucleus; 2=brush border (microvilli); 3=lymphocyte. |
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Term
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Definition
| Detail of simple columnar epithelium with a goblet cell secreting mucus. The thin, clearly defined band along the top epithelial surface is the striated border, though the individual striations (or microvilli) are not visible at this magnification. The lower edge of the striated border is the location of the terminal web; the dots along the line of the web, seen in between the individual epithelial cells, are the so-called terminal bars, which are found in EM to consist of various cell junctions |
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Term
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Definition
| Pseudostratified ciliated columnar epithelium from the trachea. Nuclei are at different levels. All cells touch the basement membrane, but only the taller cells reach the lumen. The cilia are longer and less regular than the microvilli of a striated border. |
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Term
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Definition
| Pseudostratified ciliated columnar epithelium with pale goblet cells. The different levels of nuclei are clearer here. Again, notice the wavy-looking cilia. |
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Term
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Definition
| Transitional epithelium of the urinary bladder, low power view. It is a stratified epithelium with several layers of cells. |
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Term
| Functions of Epithelial Tissue |
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Definition
| Protection, absorption, secretion, sensory (olfactory epith.), contractility (myoepithelial cells of glands) |
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Term
Epithelial Cells
How many cell types in body?
% classifed as epithelial cells?
% of adult cancers that arise from epith? |
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Definition
>200 cell types
~60% are epith cells
>90% cancers arise from epith. |
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Term
| Epithelial Cell Definition |
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Definition
| tightly adherent cells w/ scant extracell. matrix; cells tethered together by various types of adhesive jxns |
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Term
| Epithelial Cell Embryonic Origin |
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Definition
Ectoderm (skin, mouth, nose, anus)
Mesoderm (endothelium lining blood vessels)
Endoderm (cells lining resp. and digestive tracts) |
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Term
Vascularity of Epithelium
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Definition
Epith. is avascular
nutrients, waste, gases exchanged via capillary beds in underlying connective tissue (diffusion) |
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Term
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Definition
faces environment or lumen of tube or follicle
usually has spec. surf. structures (microvilli, cilia, stereocilia) |
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Term
| Lateral and Basal (Basolateral) Domain |
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Definition
| faces internal milieu (mil-yoo; french word for environment) |
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Term
| Structural Organization of Ducts |
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Definition
Duct (Simple vs. Compound)
Secretory Unit
Simple - (tubular, coiled tubular, branched tubular, acinar)
Compound - (tubular, acinar, tubuloacinar) |
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Definition
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