epithelial tissue Flashcards
4 types of tissue
- epithelial tissue
- connective tissue
- muscle tissue
- nervous tissue
what are the three origins of epithelial tissue?
- endodermal
- mesodermal
- ectodermal
endodermal
gut, respiratory track, urinary track
mesodermal
kidney, reproductive tract, muscle and blood
ectoderm
epidermis/outer layer of skin, nervous system, mouth + anus
4 functional properties of epithelial tissue
- coverings, linings + protective surfaces
- transport (absorption/secretion)
- contractile
- sensory
is epithelia vascularized?
no
gap junctions are important for what?
communication–> signaling molecules can travel between cells
syncytium
a single cell or cytoplasmic mass containing several nuclei, formed by fusion of cells or by cell division of nuclei
purpose of microvilli?
increase surface area
absorption epithelia
presence of enzyme sieve
purpose of stereocilia?
increase surface area
absorption
can be branched
purpose of cilia?
movement–> flow + moving of mucus
simple squamous epithelium
single layer of cells
squamous= flat
connective tissue
nucleus bulges
simple cuboidal epithelium
cuboidal= single layer, square or a cube
nuclei spaced
connective tissue beneath the epithelium
simple columnar epithelium
single layer
cells sitting on a basal membrane
surface orientation quiet variable
stratefied epithelium
2 collagens, not vascularized
don’t have their own blood supply
stratum corneum
dead layer of squamous cells
what is the order from the top to bottom of strata of epidermis in skin?
stratum corneum
stratum lucidum
granulosum
stratum spinosum
stratum basale
dermis
pseudostratified epithelium
appears to be stratefied but is not
all the cells sit on the basal membrane
ciliated border and terminal bar at top
types of epithelial cells (6)
squamous
cuboidal
columnar
simple
stratified
pseudostratified
