cell junctions and epithelium Flashcards
five types of cell junctions
tight
adherens
desmosomes
hemidesmosomes
gap
tight cell junctions+Eg
prevent leakages Eg urinary bladder
adherens+Eg
joins multiple cells together for one function Eg cardiac muscle
desmosomes+Eg
links intracellular to intermediate filament Eg epidermis
hemidesmosomes+Eg
anchor epithelial cells to the basement membrane Eg skin
Gap+Eg
joins two cells and allows the flow of ions and molecules Eg neurons
types of epithelial tissue
covering and glandular
what is epithelial tissue
uninterrupted layer of tightly packed cells which is avascular
what is the basement membrane
two layers which join to the epithelium and lamina propria
types of epithelia
simple, stratified =squamous, cuboidal columnar
transitional, pseudostratified columnar
what is simple squamous cells, function, Eg location
flat irregular shapes tightly packed in a mosaic pattern
function, diffusion and filtration
location-pulmonary alveoli , kidney
what is simple cuboidal epithelium, function, Eg location
tightly packed cubed shaped cells with central nuclei
function-secretion, filtration and absorption
location glands and glandular organs
what is simple columnar epithelium, function, Eg location
column shaped cells tightly packed with the nucleus positioned towards the basement membrane
function-protection, lubrication, secretion and absorption
location-lining of the intestines, uterine tubes and bronchioles
pseudostratified epithelium
cells are different heights with variable nucleus locations, can be ciliated or non ciliated
function of ciliated pseudostratified epithelium cell, and Eg of location
protection, secretion of mucin, movement of particles and mucus
location-bronchi, trachea, nasal cavities
function of a non-ciliated pseudostratified epithelium cell
protection
location-male urethra, epididymis
what is stratified squamous cell, function, location
flattered cells on the surface of then random shaped bellow, can be either keritinised or non keritinised
function-top layer wears away and tears
location-keritinised(dry)=skin, epidermis
non kertinised(wet)=mouth, esophagus,larynx,vagina,anal cavity
what is transitional epithelium, function, location
cell shape is based off of the level of distension, flat when stretched and cuboidal when relaxed
function protection and distensibility
location-lining of the urinary bladder, ureters, renal calyces
what is stratified cuboidal epithelium, function, location
two or three layers of cuboidal cells
function-protection, secretion
location-duction of sweat glands, pancreas
what is a glandular epithelia
cells specialised for the secretion of proteins, lipids, salts, carbohydrates
