bones Flashcards
(25 cards)
other name for compact bone & spongy bone ?
cortical bone
trabecular
what are the two membranes of the bone
-periosteum
-endosteum
describe bone growth when you hit puberty compared to menopause period
puberty-steep bone growth increases
menopause- steep decline in bone growth
what does oestorogen inhibit ?
inhibits osteoclasts
therefore less oestorogen then the more resorption and therefore less bone mass!
which mechanical loads either make bone mass increase or decrease ??
bed rest - less bone mass
high resistance sports -higher bone mass
do athletes have a higher BMD than an average person?
yes
list the two types of bone ossification & which one is the most common
-endochondral ossification
-intramembranous ossification
endochondral is the most common
where does endochondral & intramembranous ossification occur?
endochondral- long bone growth
intramembranous - flat bone , mandible, also long bone
how does endochondral ossification work?
starts as a cartilage first then ossify into bone by invasion of blood vessels
1.cartilage ‘model’ is formed first
2.cartilage is invaded by blood vessels
3.cartilage is replaced with bone
4. cartilage only remains in the epiphysis growth plate
name of cells responsible for the breaking and remodeling of bones ( dissolving and producing bone matrix)
osteoclasts - breaking down old bone
osteoblast - making new one
what are osteocytes & where are they found
are mature cells found inside lacunae
what are the two types of bone growth? and describe how they grow
-appositional growth : grows in diameter
-interstitial growth : grows in length
appositional growth bones have what on their outside and inside ?
inside - osteoclast resorbers
outside -osteoblast depositors
what mainly makes up the extracellular matrix ?
- water , minerals and proteins
what type of protein is in the extracellular matrix
collagen type 1
the extracellular matrix is Strongly cross-linked & large ‘gaps’ within fibres that provideas space for what?
hydroxyapatite crystals
describe Lamellar and woven collagen fibers
lamellar - arranged collagen fibers
woven -randomly arranged
what color of bone marrow does the medullary cavity |& spongy bone contain?
medullary cavity ;yellow bone marrow
spongy- red bone marrow ,
describe the proscess of intramembranous ossification
there is no cartilage model(doesnt have cartilage )
1. mesechymal stem cells develop into osteoproginator
2. they then mature into osteoblast which is used to make bones
what is the function of osteoclast and where are they derived ?
dissolve bone matrix ( breaking down old damaged bone )
derived from heamatopoietic stem cells
do osteoclasts have a nucleus and what are is the function of their ruffled border
yes theyre multinucleuated
ruffled border- releases acids to dissolve bone matrix
function of osteoblasts & are they mature or immature
produce bone matrix immature bone cells
where are osteoblast derived from
osteoproginator cells
once osteoblast are surrounded by the bone matrix what do they turn into?
oestocytes
