Term
|
Definition
| no blood supply (ex. epithelium) |
|
|
Term
|
Definition
| specialized extracellular matrix that anchors cells to the underlying connective tissue (lamina propria) - has 2 layers (lamina densa and lamina lucida) |
|
|
Term
|
Definition
| epithelial cells specialized for secretion |
|
|
Term
|
Definition
| a layer or layers of contiguous cells covering an outer surface or lining an inner surface |
|
|
Term
| What is goodpasture's syndrome? What component of the basal lamina does it affect? |
|
Definition
| rare autoimmune disease where patients make antibodies that bind to alpha-3 chains of type IV collagen - damages the basal lamina (type IV collagen) and epithelium causing renal failure and pulmonary hemorrhage. |
|
|
Term
| hemidesmosome: what do they contain? |
|
Definition
| anchor the basal membrane of epithelium to the basal lamina: contains integrins such as alpha-6 beta-4 to link the lamina to the keratin intermediate filament inside the cell |
|
|
Term
| desmosome (maculae adherens) |
|
Definition
| localized spot-like adhesions randomly found on the lateral plasma membranes between 2 adjacent epithelial cells |
|
|
Term
| What is pemphigus vulgaris? |
|
Definition
| skin blistering disease where patients make autoantibodies that bind to desmosomal cadherins and disrupt desmosomes and cell-cell adhesion. |
|
|
Term
| gap junction (intercytoplasmic junctions) |
|
Definition
| gap of 2 nm between adjacent cell membranes - allows communication between cells for passage of small molecules and ions; made of connexons which is a HYDROPHILIC channel made of connexins |
|
|
Term
| microvilli; found on what cells? |
|
Definition
fingerlike extensions of aplical cytoplasm that results in an increased surface area for absorption.
It is found on most epithelial cells but not as noticeable on absorptive cells |
|
|
Term
| brush border (striated border) |
|
Definition
|
|
Term
|
Definition
| 1 layer of cells (covering epithelium) |
|
|
Term
|
Definition
| two or more layers of cells (covering epithelium) |
|
|
Term
| pseudostratified epithelium |
|
Definition
| all cells contact the basal lamna but not all of them reach the free surface (covering epithelia) |
|
|
Term
|
Definition
| thin and plate-like cells |
|
|
Term
|
Definition
| six sided polygon cells (like cobblestone) |
|
|
Term
|
Definition
| tall and six sided polygons - look more rectangular than cuboidal |
|
|
Term
simple squamous epithelium
1. what?
2. where?
3. function? |
|
Definition
1. thin platelike cells in a single layer on the basal lamina
2. inner surface of tympanic membrane, parietal layer of bowman's capsule and descending loop of Henle in the kidney, respiratory space in the lung, rete testis, smallest excretory ducts of glands, mesothelium of serous cavities, mesenchymal epithelium in CT, endothelium of walls of blood and lymph vessels
3. exchange, barrier, lubrication |
|
|
Term
simple cuboidal epithelium
1. what?
2. where?
3. function? |
|
Definition
1. low prismatic cells, on the surface looks like small six-sided polygons, on the side looks like a sheet of cells that look like squares
2. small ducts of exocrine glands like the thyroid, pancreatic acini, choroid plexus, surface of ovary (germinal epithelium), thyroid follicales, inner surface of lens capsule, retinal pigment epithelia, kidney tubules
3. absorption, conduit, barrier, secretion |
|
|
Term
simple columnar epithelium
1. what?
2. where?
3. function? |
|
Definition
1. tall prismatic cells, surface looks like simple cuboidal but smaller, side looks like sheet of rectangles
2. digestive tract (stomach to anus), excretory ducts of glands such as the gastric ones, gallbladder
3. absorption, secretion |
|
|
Term
stratified squamous epithelium (non-keratinized)
1. what?
2. where?
3. function? |
|
Definition
1. thick, sheet; basal cells are made of cuboidal or columnar with rounded upper ends, on top of this are different numbers of irregular polyhedral cells that are more flat at the surface, superficial surface is made of thin squamous cells
2.moist surfaces, line wet cavities such as mouth, vagina, female urethra, anus, esophagus, part of epiglottis, part of conjunctiva and cornea of eye
3. barrier, protection |
|
|
Term
| keratinized stratified squamous epithelium |
|
Definition
1. thick, sheet; basal cells are made of cuboidal or columnar with rounded upper ends, on top of this are different numbers of irregular polyhedral cells that are more flat at the surface, superficial surface is made of thin squamous cells; the superficial cells have keratin and are reduced to scale-like lifeless residues with no nuclei
2. skin and hard palate
3. barrier, protection
2. |
|
|
Term
ciliated simple columar epithelium
1. what?
2. where?
3. function? |
|
Definition
1. tall prismatic cells, surface looks like simple cuboidal but smaller, side looks like sheet of rectangles
2. uterus, oviducts, small bronchi of lung, paranasal sinues, central canal of spinal cord
3. absorption, secretion |
|
|
Term
| What are the functions of epithelial tissues? |
|
Definition
1. protection - cover and line surfaces (skin)
2. absorption (intestines)
3. secretion (glandular)
4. sensation (neuroepithelium for smell and taste)
5. contractility (myoepithelium) |
|
|
Term
|
Definition
| electron dense layer of basal lamina with fine fibrils (20-100 nm) |
|
|
Term
|
Definition
| (lamina rara) electron lucent layer of basal lamina between basal cell surface and lamina densa (300-400 angstroms) |
|
|
Term
| What are the functions of the basal lamina? |
|
Definition
1. structural - attach epithelia to CT and organize membrane proteins
2. filtering - regulate exchange of material btwn epithelia and CT
3. regulation - bind GF's to regulate proliferation, differentiation, metabolism
4. migration - orient movement of epithelial cells |
|
|
Term
| What are the main components of basal lamina? (4) |
|
Definition
1. type IV collagen
2. laminins
3. entactin (nidogen)
4. perlecan |
|
|
Term
|
Definition
| trimeric coiled coil molecules with rodlike and globular domains for a 2-D network - found in basal lamina; problem in goodpasture's syndrome |
|
|
Term
|
Definition
| multiadhesive GLYCOproteins for a fibrous 2-D network with collagen - in basal lamina |
|
|
Term
|
Definition
| rodlike molecule cross-linking type IV collage and laminin in basal lamina to incorporate other components into the lamina |
|
|
Term
|
Definition
| large, multidomain heparin sulfate proteoglycan binding and cross-linking basal lamina components and cell surface proteins; LARGEST volume of lamina; POLYANIONIC molecule that binds water and anions |
|
|
Term
anchoring fibrils
1. what type of collagen? |
|
Definition
| type VII collagen fibrils in a heparan sulfate gel anchoring the lamina to CT |
|
|
Term
|
Definition
| in the skin: basal lamina + underlying CT (reticular lamina); HISTOLOGICAL term |
|
|
Term
|
Definition
| transmembrane receptors for proteins of the basal lamina (such as laminin)- found in hemidesmosomes |
|
|
Term
intercellular junctions:
what are the different types? |
|
Definition
junctions between neighboring cells laterally for cell adhesion and communication
1. adhering junctions (zonulae adherens, desmosomes)
2. impermeable junctions (zonulae occludentes or tight junctions)
3. communicating junctions (gap junctions or intercytoplasmic junctions) |
|
|
Term
zonulae occludentes (tight junctions)
1. appearance?
2. function?
3. composed of? |
|
Definition
-apical most junction (continuous belt around cells, closed, shut, or stopped up)
1. outer leaflets of adjacent membranes appear to fuse for a local pentalaminar appearance, interlocking networks of ridges on cytosolic face of plasma membranes of each contracting cells
2. prevent diffusion of macromolecules and some small water-soluble molecules and ions between cells
3. double row of protein particles (3-4 nm) called claudins (one row from each cell) |
|
|
Term
| What is cholera? what kind of junction is involved? |
|
Definition
| toxins fom Vibrio cholerae bacteria alter TIGHT JUNCTION permeability barriers of intestinal epithelia by changing composition or activity of the junction. results in massive loss of ions and water into GI tract and then diarrhea and lethal dehydration |
|
|
Term
zonulae adherens (adherens junctions)
1. appearance
2. function
3. composed of |
|
Definition
located near apical surface below tight junctions (continuous belt around cell and held closely)
1. membranes are held a little loser than tight junctions (150-200 angstroms), circumferential actin/myosin belt that acts as a tension cable controlling shape
2. primary adhesive junctions between neighboring cells in epithelia
3. linked by actin filaments and intercellular space contains glycoproteins called cell adhesion molecules (CAMS) |
|
|
Term
|
Definition
| meshwork of actin, intermediate filaments, and spectrin in the apical region of a cell |
|
|
Term
maculae adherens (desmosomes)
1. appearance
2. function |
|
Definition
- localized spot-like adhesions on lateral plasma membranes (adhering spot)
1. button-like points of contact between neighboring cells, more loose than adherens junctions (300 angstroms), sharply defined limits, electron-dense homogenous layer subjacent to plasma membrane in attachment plaques, contain tonofilaments
2. tight adhesion between neighboring epithelial cells, link tonofilaments between cells |
|
|
Term
|
Definition
| intermediate filaments made of cytokeratins that insert into attachment plaques of desmosomes or make hairpin turns and go back to the cytoplasm |
|
|
Term
gap junctions (intercytoplasmic junctions)
1. appearance
2. function
3. composed of |
|
Definition
- found in epithelia and in almost all other tissues EXCEPT muscle
1. between adjacent cell membranes with gap of 2 nm, hexagonal protein particules in circular patches to form a channel
2. communication btwn cells for small molecule and ion exchange
3. hydrophilic channel called a connexon that is made of proteins called connexins |
|
|
Term
| What are some specializations of the free apical surface of an epithelial cell? |
|
Definition
1. microvilli, stereocilia (increase cell surface area)
2. cilia (more foreign particles)
3. non-motile primary cilia (mechanosensory inputs) |
|
|
Term
| stereocilia: found on what cells? |
|
Definition
long, branched, flexible, non-motile process; form a pyriform tuft
- pseudostratified epithelial cells in the epididymis, ductus deferens, hair cells of inner ear |
|
|
Term
| What is the function of stereocilia? |
|
Definition
1. epididymis - increases surface area of cell for greater absorption of seminal fluid.
2. hair cells of inner ear - mechanosensing organelles that respond to fluid motion or fluid pressure changes (primarily for hearing) |
|
|
Term
|
Definition
| elongated, motile structures present in high numbers (250/cell); 5-10 micrometeres longs and 0.2 micrometers wide; 9 + 2 arrangement of microtubules that insert into basal bodies |
|
|
Term
|
Definition
| epithelia of respiratory system such as the larynx, trachea, bronchi, and paranasal sinuses to move foreign particles such as bacteria and mucus from the lungs or nose to the exterior. |
|
|
Term
|
Definition
| identical to cilia but longer and limited to one per cell with 9 + 2 arrangement and basal bodies |
|
|
Term
| where are flagella found? |
|
Definition
| spermatozoa in humans to function in motility |
|
|
Term
|
Definition
| electron dense structures at the apical pole below the cell membrane and are structurally analogous to centrioles; found in association with cilia and flagella |
|
|
Term
|
Definition
elongated structures that do not move on their own but bend on external pressures such as fluid flow; only one per cell
- renal epithelial primary cilia - 2-3 micrometers long and may reach 50 with increasing age
- prominent base at insertion into cytoplasm with swelling at distal tip
- 9 + 0 arrangement of microtubules into basal bodies |
|
|
Term
| where are nonmotile primary cilia found? |
|
Definition
| on NEARLY ALL differentiated cells of adult tissues including epithelial fibroblasts, chondrocytes, osteocytes, smooth muscle, cardiac, and skeletal muscle, photoreceptor cells, hippocampal neurons, etc. |
|
|
Term
| why are nonmotile primary cilia important? |
|
Definition
| contain protein products of genes that are disrupted in Polycystic Kidney Disease (polycystins) that form a fluid sensing mechanism to control the diameter of renal tubules |
|
|
Term
| How are covering epithelia classified? |
|
Definition
1. number of layers of cells
2. shape of cells in the most superficial layer
3. presence of cilia on free surface or keratin in the cytoplasm of superficial layer of cells |
|
|
Term
what is:
1. simple layer of cells
2. stratified layer of cells
3. psuedostratified layer of cells |
|
Definition
1. one layer
2. two or more layers
3. all cells contact te basal lamina but not all reach the free surface |
|
|
Term
| what are the three types of cell shapes for epithelia? |
|
Definition
| squamous, cuboidal, columnar |
|
|
Term
| What are the 10 types of epithelia? |
|
Definition
1. simple squamous
2. simple cuboidal
3. simple columnar (and ciliated simple columnar)
4. stratified squamous (non-keratinized and keratinized)
5. stratified cuboidal
6. stratified columnar
7, ciliated stratified columnar
8. psuedostratified columnar
9. ciliated pseudostratified columnar
10. transitional epithelium (urothelium) |
|
|
Term
stratified cuboidal epithelium:
1. what?
2. where?
3. function? |
|
Definition
1. rare epithelium
2. excretory ducts of sweat glands, large ducts of exocrine glands, developing ovarian follicles, anorectal junction
3. barrier, conduit |
|
|
Term
stratified columnar epithelium
1. what?
2. where?
3. functions?
4. ciliated stratified columnar |
|
Definition
1. relatively rate
2. small areas of the fornix of conjunctiva, cavernous part of the urethra, anal mucous membranes, pharynx, epiglottis, largest excretory duct of some glands
3. barrier, conduit
4. found on nasal surface of the soft palate, larynx, transiently in fetal esophagus |
|
|
Term
psuedostratified columnar epithelium
1. what?
2. where?
3. ciliated pseudostratified columnar
4. functions? |
|
Definition
1. nuclei are at different levels and cells are variable in shape; all cells attach to basal lamina but some do not reach the free surface
2. large excretory ducts of parotid and other glands, male urethra
3. found on greater part of mucous membrane of respiratory passages (trachea, bronchi, nasal cavity), eustachian tube, tympanic cavity, lacrimal sac, excretory passages of male reproductive system
4. secretion, absorption, conduit |
|
|
Term
What is transitional epithelium (urothelium)?
1. what?
2. where?
3. function? |
|
Definition
1. varied appearance due to mechanical changes due to contraction and distention
2. in urinary system, lining the urinary bladder, the ureter and upper part of urethra
3. barrier, distensible property |
|
|
Term
| what is metaplasia? and how is it caused? |
|
Definition
| reversible event where one differentiated cell type is replaced with another mature differentiated cell type; an adaptation to cellular stress; NOT CANCER |
|
|
Term
| what are some examples of metaplasia (3)? |
|
Definition
1. barrett's esophagus
2. airway epithelial metaplasia
3. cervical erosion |
|
|
Term
| what is Barrett's esophagus? |
|
Definition
| abnormal change in cells of the lower esophagus caused by damage from chronic stomach acid exposure |
|
|
Term
| what is airway epithelial metaplasia? |
|
Definition
| ciliated psuedostratified columnar epithelial are replaced with stratified squamous epithelia in response to cigarette smoke |
|
|
Term
| what is cervical erosion? |
|
Definition
| non-keratiniszed stratified squamous on the surface of the cervix is replaced with glandular columnar epitheliium in the cervical canal due to trauma, infection and certain chemicals |
|
|
Term
| what are secretory granules? |
|
Definition
| membrane-bound vesicles that hold secretory products |
|
|
Term
|
Definition
| from epithelium through cell proliferationn and invasion of epithelium into connective tissue |
|
|
Term
| how are glands classified? (5) |
|
Definition
1. size (unicellular/multicellular)
2. mode of secretion (exocrine v. endocrine)
3. type of secretion (serous v. mucous)
4. mechanism of secretion (merocrine, apocrine, holocrine)
5. morphology of ducts (simple v. cmpd) and secretory units (tubular, aveolar, tubuloalveolar) |
|
|
Term
Unicellular glands:
1. what?
2. function?
3. where? |
|
Definition
1. isolated glandular cells scattered among columnar epithelial cells of mucous membranes
2. secrete mucin (protein polysacc) that forms a lubricating solution (mucous)
3. ONLY one is the GOBLET CELL or mucous cell in mucous membranes of several tissues such as the small intestine, stomach, genital tract, respiratory tract. |
|
|
Term
multicellular glands
1. what? |
|
Definition
| clusters of cells which can be mucous-secreting (mucous salivary glands), serous secreting (pancreas), or both (sublingual salivary) |
|
|
Term
| What are exocrine glands? |
|
Definition
- secretions are into a ductal system
- retain connections with surface epithelium
- ducts that carry secretory product to the surface
- discharge product at an external or internal surface |
|
|
Term
| what are endocrine glands? |
|
Definition
- secrete into vascular system
- no connection with surface epithelium of origin
- do not have ducts and product is released into blood or lymph |
|
|
Term
|
Definition
| usually pyramidal with broad base on basal lamina and narrow apical surface with short microvilli, round cental nucleus, basal part of cytoplasm is basophilic due to RER, apical part of cytoplasm contains secretory granules, zymogen granules |
|
|
Term
| what are zymogen granules? |
|
Definition
| contain digestive enzymes and are found in serous glands |
|
|
Term
serous glands:
1. examples
2. alveoli
3. secretion |
|
Definition
1. parotid gland, pancreas
2. adjacent serous cells form these spherical structures (acini)
3. watery and rich in enzymes |
|
|
Term
mucous glands:
1. example
2. secretion |
|
Definition
1. goblet cell and mucous salivary gland
2. viscous and contains mucous |
|
|
Term
| what is the morphology of mucous glands? |
|
Definition
| expanded, oval apical end filled with pale droplets corresponding to large secretory granules with mucigen, flattened nucleus in the slender basal end with a small amount of deep staining basophilic cytoplasm, well-developed Golgi above the nucleus |
|
|
Term
Mixed glands:
1. what does it contain?
2. examples |
|
Definition
1. mucous and serous cells
2. submandibular and sublingual salivary glands |
|
|
Term
| What are the three mechanisms of secretion for exocrine glands? |
|
Definition
1. merocrine
2. apocrine
3. holocrine |
|
|
Term
| What is merocrine secretion? Where is it found? |
|
Definition
| the secretory granule fuses with the plasma membrane by exocytosis without losing the cytoplasm; most common mechanism; salivary glands and pancreas |
|
|
Term
| What is apocrine secretion? where? |
|
Definition
| the secretory granule + apical cytoplasm is lost; mammary glands and sweat glands |
|
|
Term
| what is holocrine secretion? where? |
|
Definition
| the entire cell becomes the secretory product and is shed; uncommon; sebaceous gland |
|
|
Term
|
Definition
| one unbranched duct (exocrine gland) |
|
|
Term
| what is a compound gland? |
|
Definition
| branching duct system (exocrine) |
|
|
Term
| what are the types of secretory ducts? (8) |
|
Definition
1. simple tubular
2. simple coiled tubular
3. simple branched tubular
4. simple acinar
5. branched acinar
6. compound tubular
7. compound acinar
8. compound tubuloacinar |
|
|
Term
| simple tubular secretory unit? |
|
Definition
| found in the large intestine and colon; secretory portion is a straight tube formed by goblet cells |
|
|
Term
| simple coiled tubular secretory unit? |
|
Definition
| found in the skin, eccrine sweat gland; secretory portion is a coiled tube located deep in the dermis |
|
|
Term
| simple branched tubular secretory unit? |
|
Definition
| found in the stomach, mucus-secreting glands of pylorus; secretory portion is branched and produces a viscous and mucous secretion |
|
|
Term
| simple acinar secretory units? |
|
Definition
| found in the urethra, paraurethral and periurethral glands; secretory portion is formed by small, sac-like dilations of secretory cells that develop as an outpouching of the transitional epithelium |
|
|
Term
| what is a branched acinar secretory duct? |
|
Definition
| found in the stomach, mucous secreting glands of the cardia; mucous secreting portions are connected to sort, single duct portions that open directly into the lumen |
|
|
Term
| what is a compound tubular secretory duct? |
|
Definition
| found in the duodenum and submucosal glands; coiled secretory portions are located deep in the submucosa of the duodenum |
|
|
Term
| what are compound acinar secretory units? |
|
Definition
| found in the pancreas, excretory portion; alveolar shaped secretory units are formed by pyramid shaped serous secreting cells |
|
|
Term
| what are compound tubuloacinar secretory ducts/ |
|
Definition
| found in the submandibular salivary gland, mammary gland and lacrimal gland; can have both mucous branched tubular and serous branched acinar secretory units with serous end caps called demilunes |
|
|
Term
|
Definition
| tumor of epithelial cell orgin; reflects cell specific morphology and behaviors; those that are undifferentiated are hard to diagnose |
|
|
Term
| what is an adenocarcinoma? |
|
Definition
| tumor derived from glandular epithelial tissue |
|
|
Term
| which epithelial type is the most highly specialized to accomodate stretch? |
|
Definition
|
|
Term
| an elderly male patient with chronic digestive problems involving absorption of fluid has a biopsy performed on his small intestine. What structure does the biospy report cite as being affected? |
|
Definition
|
|
Term
adenocarcinoma: from which of the following would this tumor not has arisen?
(breast, prostate, salivary gland, pancreas, kidney) |
|
Definition
|
|
Term
|
Definition
| the space BETWEEN epithelial cells |
|
|
Term
|
Definition
| affects type VII collagen gene and causes blistering |
|
|
Term
|
Definition
| between cells; transport from one cell to another |
|
|
Term
| what is flagella made of? |
|
Definition
|
|
Term
|
Definition
| found in the kidney for filtration; form of simple cuboidal cells |
|
|
Term
| what is the most common stratified epithelia? |
|
Definition
|
|
Term
|
Definition
| vascularized lamina propria that interdigitates into epithelia to deliver nutrients to deeper cells |
|
|
Term
| Which form of glandular secretion leads to cell death? which does not lead to cell death? |
|
Definition
cell death = holocrine
no death = apocrine and merocrine |
|
|
Term
|
Definition
| flow of sebum is stopped (holocrine secretion) |
|
|
