5 Written questions
5 Multiple choice questions
- From monocytes
Osteoblasts secrete both OPG and RANKL
OPG binds and inhibits RANKL
RANKL causes osteoclast maturation
- Runx2 ~> osteocalcin ~> osteoblast.
Twist inhibits Runx2
without it, no bone!
(Runx2 is also for chondrocytes)
- Inactivated RSK2.
ATF4 isn't turned on
can't import AA or fully differentiate osteoblasts
treated with high protein diet
- Chondrocyte, osteoblast, osteoclast
Growth Formation Resorption
- Regulator of osteocalcin promoter
activated by RSK2 kinase
knockout leads to osteogenesis (smaller/thinner bone)
Without, have trouble importing amino acids (high protein diet can fix)
4 True/False questions
Proliferation of chrondrocytes → Runx2 ~> IHH ~> Proliferation
Twist inhibits Runx2 as well
However, IHH also induces PTHrP which inhibits IHH.
This elongates the proliferative stage so you have enough cells before entering hypertrophy.
Disorders of intramembranous bone formation → Delay: Msx2, Runx2 haploinsufficiencies
Acceleration: FGF, MSX2 activating mutations. twist haploinsufficiency
Cleidocranial dysplasia → Runx2 haploinsufficiency
osteoblasts don't form and you have weak bones, no clavicle, and gap in skull
Three stages of bone development → Patterning ~> Skeletogenesis ~> Homeostasis
Lethal Lethal 50% population problems