5 Written questions
5 Multiple choice questions
- Somites ~> Axial
Lateral plate mesoderm ~> appendicular
Cranial neural crest ~> craniofacial
Monocyte ~> osteoclasts
- Runx2 haploinsufficiency
osteoblasts don't form and you have weak bones, no clavicle, and gap in skull
- Chondrocyte, osteoblast, osteoclast
Growth Formation Resorption
- From monocytes
Osteoblasts secrete both OPG and RANKL
OPG binds and inhibits RANKL
RANKL causes osteoclast maturation
- 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
Regulation of chondrocytes → 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
Proliferation of chrondrocytes → Via sox9.
Haploinsufficiency leads to dwarfism.
Osteoblast Differentiation → Runx2 ~> osteocalcin ~> osteoblast.
Twist inhibits Runx2
without it, no bone!
(Runx2 is also for chondrocytes)