L7+ L8: Musculoskeletal pathologies 1 & 2

Question 1

what is myasthenia graves ?

Answer 1

production of antibodies against acetylcholine (nicotinic ) receptors present on the postsynaptic neurotransmission junction

Question 2

what are the clinical features of myasthenia gravis?

Answer 2

skeletal muscle weakness

diploma : double vision

ptosis : drooping of eyelids

dysphagia : difficulty swallowing

dyspnea: difficulty breathing

Question 3

what gene is affected in achondroplasia ?

Answer 3

FGFR3, Mutation prevents conversion of cartilage to bone . the gene controls the growth rate of long bones

Question 4

what kind of ossification is impaired in achondroplasia ?

Answer 4

endochondrial ossification

Question 5

what does osteopenia mean?

Answer 5

decrease in bone mass / bone mineral density

Question 6

what does osteoporosis mean?

Answer 6

osteopenia that is severe enough to significantly increase the risk of fracture due to an increase in bone fragility.

Question 7

what is rabdomyoma?

Answer 7

benign tumor of striated muscles

Question 8

where does the adult rhabdomyoma originate from ?

Answer 8

skeletal musculature of 3rd and 4th branchial arches

Question 9

what are leiomyomas??

Answer 9

benign smooth muscle tumor

Question 10

where can leiomyomas be seen?

Answer 10

they are most common in the uterus but they can also be seen in the oral cavity ( arise from smooth muscle layer in vessels)

Question 11

what is Ewings sarcoma ?

Answer 11

Primary malignant tumor of bone that is composed of small undifferentiated round cells.
Genetics: translocation between chromosome 22 and 11