L4 epithelium Flashcards
what is meant by cell polarity
each surface different and specialised for a different function eg apical vs basolateral
what are the 3 cell domains
apical
lateral
basal
specialisations of the apical surface
glycocalyx coating
cilia
microvilli (glycocalyx coating)
what regions of the apical surface will have no glycocalyx layer?
cilia regions
how does the glycocalyx layer appear in a histological image
orange - brown band
function of glycocalyx in epithelial cells?
- cell recognition
- intercellular adhesion
- cell communication
what can be found in the glycocalyx
glycolipids and glycoproteins
function of glycocalyx in endothelial cells
regulates permeability
where are cilia found and how do they appear
hair like
trachea, uterine tube
describe appearance of microvilli
tall closely packed projections
microvilli function and where theyre found
absorption
SI
how can determine cilia from microvilli
cilia longer and thinner and are not surrounded by glycocalyx
basal lamina function
cell adhesion interface
permeability barrier
lateral region function
cell to cell interactions
what defines ‘simple’ epithelium
single cell layer
what defines ‘stratified’ epithelium
two or more layers of cells
where is simple epithelia likely to be found
absorption/diffusion/secretion surfaces
eg
lungs
SI
where is stratified epithelium likely to be found
sites prone to mechanical abrasion
pharynx
oesophagus
cervix
describe squamos cells
look flattened
wider than they are tall
describe cuboidal cells
cube shape
same width and height
describe columnar cells
like rectangles
higher than they are wide
where will simple squamos epithelia usually be found
lungs
capillaries
describe features of pseudostratified epithelium
appears stratified (more than one cell thick) all cells sit on basement membrane but not all reach surface
where is the nuclei of pseudostratified epithelium usually located
towards basal end
