Cartilage and ossification Flashcards
what are the properties of cartilage
maintains form
resists deformation
flexible
due to matrix of collagen and proteoglycans
what are the two ways that cartilage can grow
interstitial growth - mitosis
appositional growth - add cartilage onto the outside
does cartilage have nerves and blood vessels
no
what is cartilage composed of
2 parts:
cells - chondrocytes
ecm
what is cartilage ecm composed of
fibrous component - collagen type 2
ground substance - proteogylcans and gags
which type of collagen is found in cartilage
type 2
which gag is found in synovial joints?
hylauronan
what is a proteoglycan
core protein with gags
what is a proteoglycan aggregate
proteogylcans stuck to hylauronic acid
what is the role of proteoglycan aggregate
create a high swelling pressure and make it permeable
why are there rings of cartilage in airways
prevent airway collapse
what are the three types of cartilage joints
symphysis
synovial
synchondrosis
as get older what happens to cartilage
more cartilage gets mineralised
what are the two processes of bone formation
endochondral - cartilage becomes bone - for long bone
intramembranous - where osteoblasts form bone directly
what happens to the growth plate at puberty
it is ossified and disappears under the influence of sex hormones - oestrogen
where are the three areas that mineralisation of cartilage occurs
hyaline cartilage in elderly
tidemark zone
endochondral ossification
vitamin d deficiency ?
rickets in children - no mineralisation
osteomalacia in adults - which causes lack of mineralisation
= defective mineralisation
what is the name of condition in which there is cartilage destruction?
osteoarthritis - due to wear and tear
how does it present in histology
irregular mineral tidemark
what is the AUTOIMMUNE CONDITION that results in cartilage destruction?
rheumatoid arthritis - inflammatory cytokines tnf-alpha and il1 are seen - antibodies against tnfalpha in some patients are effective
