adhesion and ecm Flashcards
what are the 6 connective tissue cells?
- fibroblasts
- myofibroblasts
- blood derived products
- osteoblasts
- chondroblasts
- adipocytes
what 2 things combine to make polysaccharides?
glycosaminoglycans and specific proteins
what is the ecm made from
fibrillar proteins - elastin, collagen, laminin, fibronectin.
GAGS
fibroblast function
synthesis and secrete collagen, elastin, proteoglycans
why is collagen secretion special?
- because collagen is packaged into specialised large vesicles in the RER.
- secretion occurs by exocytosis at specialised sites.
what is the membrane tube that collagen is produced in?
fibropositor
where are elastic fibres secreted from?
fibroblasts
smooth muscle cells
chondroblasts
how does elastin recoil?
it recoils because of its hydrophobic effect, it wants to recoil when it is stretched because its hydrophobic fibres are exposed to aqueous environment.
proteoglycan function?
- matrix support (cushioning/hydration)
- glue like function
what will intern attach to?
it is a transmembrane protein that will attach to fibronectin on the outside and an adaptor protein on the inside.
describe GAGs
- they are long chains of repeating disaccharide units.
- highly charged and highly hydrated.
what does hyaluronic acid do?
it links between the ecm and cytoskeleton. (across the plasma membrane)
what will collagen and proteoglycans link too?
fibronectin
what are the 2 functions of myofibroblasts?
fibroblast like- secretes collagen
smooth muscle like - synthesises collagen, myosin and desmin.
what is myofibroblasts involvement in tissue damage?
- proliferate
- secrete collagen for scaffold
- consolidate damage area (fibrous scar)
- contract (reducing the size of the damaged area)
how to myofibroblasts differentiate from fibroblasts?
they have different mechanical tension especially during wound healing.
granule content of mast cells?
heparin and histamine
plasma cells?
they produce antibodies through the secretory pathway
3 functions of adipocytes?
- insulation
- packing
- energy store
describe the shape of adipocytes?
they have a large lipid droplet with a peripheral cytoplasm and a squished nucleus.
what happens when adipocytes are paraffin embedded during staining?
the lipid will be lost during the processing
what can a mutant ob gene cause?
- excessive eating
- obesity