Epithelial Tissue Flashcards
Give a quick overview of epithelial tissue - location, functions, classification, blood supply, types of cells, separated from CT
lines internal/external surfaces of body, has specialized functions (absorption, secretion, transport, protection), can be simple or stratified, avascular, polarized cells, separated by underlying CT by basement membrane
simple squamous epithelium
lines blood vessels (endothelium), pleura, peritoneal and other serous cavities (mesothelium)
stratified squamous non-keratinized epithelium
lines moist body surfaces (lie closest to lumen) - mouth, esophagus, vagina
stratified squamous keratinized epithelium
skin!
simple cuboidal epithelium
lines distal tubules in the kidney, follicles of thyroid gland, surface of ovary
stratified cuboidal epithelium
lines the ducts of sweat glands (otherwise uncommon)
simple columnar epithelium
lines stomach, intestine and excretory ducts of many glands
stratified columnar epithelium
occasionally found in large excretory ducts of some glands and in cavernous urethra of penis (relatively uncommon)
pseudostratified columnar epithelium - why is it pseudo? location? types of cells?
every cell rests on basal lamina but not all the cells reach the lumen - lines trachea, primary bronchi, excretory ducts in parotid gland, epididymis (with stereocilia) - may have muscous or goblet cells
transitional epithelium
lines excretory passages in urinary sytem - from renal calyces to urethra
hemidesmosomes
present along basal surface of cells - stratified squamous epithelia, myoepithelial cells in mammary and salivary glands, basal cells in tracheal epithelium.
microvilli - structure and function
brush border, have a sugar coat, contain bundle of 30 actin filaments - absorption
stereocilia - structure and function
not cilia, but long Mv, in epididymus and vas deferens, no motility - absorption
cilia - structure
9 doublets + 2 single = axoneme
basal body - 9 triplets + 0
endocrine glands - define, classification
secret into blood, no ducts - can be unicellular or multicellular
exocrine gland - define, classification
have gland -
unicellular (goblet cell), multicellular [simple = no branch, compound = branch in duct]
acinar/alveolar = sac like
tubule = strait or coiled
parotid gland
only serous units
sublingual gland
both mucous and secretory units
What is merocrine method of secretion?
exocytosis
what is apocrine method of secretion?
part of the apical cytoplasm is release along with the secretory material
what is holocrine method of secretion?
entire cell contents are released
how do epithelial tissues get blood suppply since they are avascular?
diffusion of molecules through basal lamina
what is zonula occuldens and what does it use?
its a tight junction
uses occudin
what is zonula adherens and what does it use?
its a belt desmosome uses E-cadherins calcium actin viniculin
what is macula adherens and what does it use?
its a demo some uses dense plaques and desmoplaquins (intracellular proteins) keratin transmembrane linker cadherin
what do gap junctions use?
nexus, connexons = communicating junction
what interlocks adjacent epithelial cells?
lateral interdigitations
what makes up the basement membrane
basal lamina - lamina lucida, lamina rare +
reticular lamina
what adheres cells to basement membrane? what do they use?
hemidesmosomes
use integrins
plauqe
what adheres cells to basement membrane? what do they use?
hemidesmosomes
use integrins
plauqe
