Quiz 1 Flashcards
what do most oral/pharyngeal cancers derive from?
90% derive from epithelial cells
what tooth structure is derived from epithelial cells? what is the development disorder associated with it called
enamel
amelogenesis imperfecta
what are the biotypes of gums and how is it checked for?
thin and thick biotypes. A probe is stuck under the gums and if it is visible it is the thin biotype, invisible it is thick
what type of cells make up the gingiva
keratinized epithelium
what are the functions of epithelial tissue?
- physical protection
- barrier / permeability control
- sensation trigger
- secretion
- excretion
- gas exchange (lungs)
- gliding lubrication (mesothelium)
what is the function of simple squamous epithelium?
they allow materials to pass by diffusion and filtration in sites where protection is. not important (blood vessel lining) –> unlike protection thats needed in intestins or skin
where are simple squamous epithelium found (include subtypes and where theyre found)
(simple squamous includes endothelium and mesothelium)
endothelium : blood vessel lining, lining of heart, and lymphatic vessels
mesothelium: peritoneum, pleurae, pericardium (serous membrane)
also found in : glomeruli, skin, alveoli lining
What is the function of simple cuboidal epithelium?
absorptive or secretory
where are simple cuboidal cells located?
kidney tubules, ducts and secretory portion of small glands(merocrine, apocrine, holocrine) , ovary surface
what is the function of simple columnar epithelium?
absorption, secretion of mucus, enzymes, and other substances (apical specialization - microvilli- increase absorptive area
what are the functions of simple columnar epithelium?
absorption, secretion of mucus, enzymes and other substances, lining of stomach
where are simple columnar epithelial cells found
small intestine, excretory ducts of some glands, lining of stomach, goblet cells (specialized ones)
what are microvilli and how do they appear histologically
fingerlike cytoplasmic extensions that increase absorption area. not visible with light microscopy, you see a brush border instead (lighter pink border)
-apical specialization on simple columnar cells of intestine
what are the functions of pseudostratified epithelium?
secrete substances (mucus mostly), propulsion of mucus by ciliary action
what are cilia
apical specialization (pseudostratified epithelium) -long hairlike extensions (dont have cytoplasm in them) have back and forth movement to move things along/clear out
where is pseudo-stratified epithelium found?
respiratory tract (trachea,bronchi), nasal cavity, excretory ducts in parotid gland
what are the basal cells of stratified squamous epithelium
cuboidal or columnar and metabolically active whereas surface cells are flattened (squamous)
what is the function of stratified squamous epithelium
protects underlying tissues in areas subjected to abrasion
where is stratified squamous epithelium
keratinized: epidermis of skin, hard palate, gingiva.
nonkeratinized: moist lining of the esophagus, mouth and vagina, true vocal chords
where is transitional epithelium found
mostly in the urinary tract, also called urothelium. characterized by dome shape outer cell layer , it can also stretch so it is a thinner layer when the bladder is full . Lines urinary passage from renal calyces to urethra.
where is stratified cuboidal epithelium found
lining of ducts in sweat glands
where is stratified columnar found
lining of large excretory ducts in some glands and cavernous urethra
endocrine vs exocrine glands
endocrine secrete into the bloodstream, exocrine secrete into an extracellular space (duct)
*simple cuboidal?
what is an example of unicellular exocrine glands
goblet cells
what are the shape characteristics of multicellular exocrine glands
shape:
tubular
acinar (circular shape)
tubuloacinar (tube leading to globular shape)
-simple or compound branched!!
so theres simple tubular, acinar, and tubuloacinar and then there is compound tubular, compound acinar, and compound tubuloacinar— submandibular salivary glands!
describe the descending lateral (apical-> basal) junctions of epithelial cells
First there are tight junctions (or occluding junctions, zonula occludens) these function as a barrier. The cell membranes themselves are connected/fused by strands of transmembrane proteins such as claudins and occludins— creates impenetrable seal
Then there are the Adhering Junctions :
- zonula adherens (link actin cytoskeleton)-intercellular bridging proteins linked to actin filaments of cytoskeleton
- desmosomes/macula adherens (protein connection for stress/mechanical pull)-intercellular bridges linked to cytokeratins
- —provide structural cohesion/stability
-lastly Gap Junctions: allow electrical coupling of cells by direct cytoplasmic connections (connexons)-allows intercommunication
how are epithelial cells anchored
HEMIDESMOSOMES= they are anchored on the basal side to the basal lamina of the basement membrane. They are linked by integrins , provides stability to the whole tissue. hemidesmosomes are like desmosomes, integrin proteins.
what makes up the basement membrane
synthesized by epithelial cells and underlying connective tissue (its all connective tissue)
- basal lamina : Integrins attach it to the epithelial cells. includes lamina lucida and lamina densa (Collagen IV of lamina densa)
- underlying reticular tissue (lamina reticularis): Collagen III mostly, proteoglycans
reticular connectivev tissue attaches to the basal lamina with vollagen VII anchoring fibrils and fibrillin microfibrils
osteogenesis - what is it for teeth??
abnormalities in collagen formation- bones arent well formed, fragile bones break easily because collagen isnt assembled well.In teeth its called dentinogenesis imperfecta
what is ehlers danlos syndrome
gene for making collagen (type I?) col1a1 and col1a2 genes- hyperextensibility of skin
what is marfans syndrome
elastin syndrome- effects skin, dermis, hyperextensibility of joints, fragility in the walls of vessels so rupture in vessels occurs because theres not a good elastin layer.
what is the ECM made up of (general)
fibers: collagen (includes reticular), elastic fibers
ground substance: amorphous gel like substance. basically everything else. made of water and organic materials like proteoglycans, glycoproteins etc.
what are mesenchyme cells and what do they turn into
embryonic connective tissue
they make chondroblasts, lipoblasts, fibroblasts, osteoblasts, and myoblasts (of skeletal muscle )
what cells make cartilage, bone and skeletal muscle
cartilage: chondroblasts
Bone: osteoblasts
skeleta muscle : Myoblasts
what do fibroblasts make
ligament, tendon, capsules, general supporting tissues
most numerous in ct
synthesize and degrade collagens, elastin, proteoglycans and other ECM proteins
macrophages-function and appearance
involved in
- host defense against pathogens
- removal of cellular debris during would healing and tissue remodeling
- turnover of old erythrocytes
- phagocytosis of foreign substances
– irregular nuclei (double shape) large cells
mast cells-function and apperance
involved in innate and adaptive immune responses. allergys- used for immediate reactions. a bunch of circles surroundiing a vacuole-little circles are granules containing antihistamine and heparin
pinker staining?
plasma cells function and appearance
antibody secreting cells (in CT, variable amounts- more when infected)
- large oval cells with basophilic cytoplasm (dark staining) peripheral clumps of heterochromatin cause a “clock-face” appearance
- white blob in them is golgi apparatus which glycosylates the antibodies (which are glycoproteins)
- plasma cells leave their site of origin in lymphoid tissues and move to connective tissue-produce antibodies that mediate immunity