Tissue Epithelial (wk3 ch5.2) Flashcards
Epithelial tissue consists of
a sheet of closely adhering cells one or more cells thick with the upper surface usually exposed to the environment or to an internal space in the body
what are the 6 functions of epithelia tissue
-protection
-secretion
-excretion
absorption
-filtration
-sensation
what does avascular mean?
without blood vessels
Describe what epithelia cells look like?
avascular, there is no room for them between the cells
describe locations of typical epithelial tissue
vessel-rich layer of connective tissue (to furnishes with nutrients and waste removal)
what is a then layer of glycoproteins, collagen, and glycosaminoglycans beneath the deepest of an epithelium serving to bind the epithelium to the underlying tissue
basement membrane
basal surface is
the lowest surface of an epithelial cell attached to either a basement membrane or an underlying epithelial cell.
apical surface is
the uppermost surface of an epithelial cell, usually exposed to the lumen of an organ
located between basal and apical surface as the “sidewall” of a cell
lateral surface
two broad categories of epithelia
- simple (every cell is anchored to the basement membrane)
- stratified (some cells rest on top of other cells and do not contact basement membrane)
three cell shapes
- squamous
- cuboidal
- columnar
pseudostratifed columnar is
type of simple that gives a false appearance of multiple cell layers sometimes looks like stratified
has only one layer of cells; four types
simple epithelium
where are goblet cells often found and what are they?
- in simple columnar and pseudostratified columnar
- wine glassed shaped and produce protective mucous coatings over the mucous membranes
range from 2 to 20 or more layers of cells with some cells resting directly on others
stratified epithelia
fourth type of stratified epithelia found in urinary tract
urothelium
most common epithelium?
Stratified squamous epithelium (deepest layer of cells are cuboidal to columnar and include mitotically active stem cells)
exfoliate cytology is?
study of exfoliated cells
what does keratinized (cornified) mean?
covered with a layer of dead compressed cells called Keratinocytes packed with durable protein keratin and coated in water repellent gycolipid
what is nonkeratinized mean?
lacks the surface layer of dead cells. Is abrasion-resistant, but moist and slippery
what are the domed surface cells of urothelium called and why are they important
- umbrella cells
- the outer phospholipid layer of the plasma membrane is thicker than usual and has dense patches called lipid rafts with embedded proteins called uroplakins
