Week 2 Flashcards
What kind of tissue is bone?
connective
Why is the bone structure ‘hard’?
calcified extracellular matrix (ECM)
Name some reasons that bones change throughtout your life.
age
intense pressure/movement
rebuilding from trauma
what are the bones 2 extracellular components?
organic - made of proteins
inorganic - made of minerals
what is the organic portion of the bone made of and what portion of the bone does it make up?
33% of bone in organic.
made of collagen (protein fibres)
and ground substance (proteoglycans)
what is the reason we have organic components in our bones?
organic means more flexible
resists tension
more bendy - less likely to snap.
woud be too bendy on its own
what is the organic portion of the bone made up of and what portion of the bones makes it up?
67% of the bone is inorganic
made of hydroxyapatite + ca minerals (salts)
what is the reason that we have inorganic compontents in our bones?
hard + resistent to compression
would be too brittle on its own (snap instead of bend)
what are the 4 types of bone cells and what are their function?
what % of the bone do they make up?
2% of the bones are cells
- ostgegenic (create osteoblasts)
- osteoblasts - MAKE create/build bone
- osteocytes - MAINTAIN tell other what to do, responsible for correct amount of destruction/formation.
- osteoclasts - DESTROY remove bone matrix
compact bone is arranged into a structural unit called a:
osteon
cancellous bone is made of a ___ structure.
trabecular
what are foramina?
holes in bones. they can let blood vessels in in order to supply blood and therefore nutrients to the bone tissue.
explain how blood supply enters into compact bone.
blood supple enters in through foramina and travels up the central canal of the osteons where the nurtients are carried through the canaliculi to the lacunae and therefore the entire osteon.
explain why blood supply enters into compact bone.
blood supply means that nurtients are reach all parts of the osteon and therefore it was heal/repair/function better/faster.
name the four parts of an osteon:
- central canal
- lamellae
- lacunae
- canaliculi
what is the central canal and what is its function?
blood vessels and nerves that travel up the centre of the osteon in order to supply nutrients to the osteon and therefore keep the bone healthy.
what is the lamellae and what is it made of?
layers around the central canal that form the shape of the osteon made of inorganic ECM (collagen, flexible)
what is the lacunae and what is its function?
‘lakes’ or voids between lamellae that house osteocytes
what is the canaliculi and what is its function?
channels through the ECM from the central canal to the lucanae that supply nurtients to the osteocytes.
What does ecm stand for?
extracellular matrix
long bones have an extra layer or ____ outside of the ___
circumferential lamellae , osteon
what are interstitial lamellae?
old osteons that are squished and will eventually be remodelled.
what is cancellous bone mostly made up of? (2)
trabeculae (little arms of weblike bone tissue, struts of lamellae)
marow that fills the gaps between the trabeculae
Where the osteocytes housed in cancellous bone?
in lacunae in between lamellae on the surface.