How tissues are made from cells Pt2 L10 Flashcards
function of epithelium (4)
barrier
protection
maintenance
transportation
types of junction (4)
Adherin junction
desmosomes
tight junction
gap junction
what are adherin junctions
anchor cells by forming a continuous belt around the epithelium
use cadherin proteins for interactions with neighbours
desomosomes
pinpoint buttons of focal adhesion
have specialised cadherins
what are cadherins
adhesive glycoproteins that are homodimers (match partners)
what are gap junctions
allow the movement of small molecules between adjacent cells so they respond identically to intracellular signals
what are tight junctions
prevent the movement of substances down the paracellular cleft
2 sides of a cell
apical and basolateral
why are cells polarised
allows specialised activities which are directional
types of epithelium
simple squamous simple cuboidal simple columnar Pseudostratified columnar stratified
what is the extra cellular matrix (ECM)
aqueous basis of connective tissue
what is the ECM for
diffusion of O2, nutrients and waste
2 parts of the ECM
fibrous elements
viscous elements
what makes up the fibrous elements of the ECM
collagen and elastin to resist tensile force
what makes up the viscous element of the ECM
glycosaminoglycans
to resist tensile forces
location of simple squamous epithelium
alveoli
blood vessels
lymph vessels
location of simple cuboidal epithelium
ducts and secretory portions
location of ciliated simple columnar epithelium
ciliated tissues in bronchi, uterine tubes
non ciliated simple columnar epithelium
digestive tract and bladder
pseudostratified columnar epithelium
ciliated line the trachea and most the upper respiratory tract
stratified squamous lines
oesophagus, mouth vagina
transitional epithelium=
lines the bladder
What are protoglycans made off
glycoaminoglycans and core proteins
what do protoglycans do
trap water
what is the main adhesion protein of ground substance
fibronectin
what does fibronectin do
binds collagen fibres and ground substance
