MMB (048) Normal and Abnormal Bone Growth Flashcards
which is wooven and lamelar bone ?
explain Intramembranous ossification in 4 points
Bones formed by Intramembranous Ossification ?
Bones formed by Endochondral Ossification ?
• The most common disease of the growth plate and the major cause of dwarfism ?
Achondroplasia
Inheritance of Achondroplasia ?
autosomal dominant
Pathogenesis of Achondroplasia ?
-In normal development , FGFR3 has a negative regulatory effect on bone growth.
In achondroplasia, the mutated form of the receptor is constitutively active and this leads to severely shortened bones
Fate of Homozygous infants with achondroplasia gene mutation ?
Homozygous infants normally die at birth or soon after from respiratory insufficiency due to a small chest cavity
Morphologic Features of Achondroplasia ?
The genes that code for the α1 and α2 chains of type 1 collagen ?
COL1A1 and COL1A2
Other organs rather than bone affected in Osteogenesis imperfecta ?
joints, eyes, skin and teeth are affected as well
The spectrum of severity for Osteogenesis imperfecta ?
Bone microscopy of Osteogenesis imperfect-a patient ; describe.
Clinical picture of Cretinism ?
• Disproportionally short limbs
• Large head due to delayed closure of fontanelles
• Mental impairment
Cause of cretinism ?
• Results from maternal iodine deficiency
Acromegaly – signs & symptoms ?