Urgent NBME 13 biochem - chuha

[ArchivalUser]

After injury to achilles tendon the Pt. undergoes repair and long leg cast immobilisation.Six month later left calf muscle shows a decrease in circumference comparted to right.Which of the following is most likely cause of this decrease

A. Decrease glycogen synthesis

B. dECREASED MYOSIN LIGHT CHAIN PHOsphatase activity

C. Increase phosphatidyl degradation

D. Increased protein degradation

E. Mitochondrial damage

F. NECROSIS OF muscle fibre

A is wrong

[ArchivalUser]

ee

[ArchivalUser]

how??

[ArchivalUser]

i thought it would be B... because the person is not moving his arm and not contracting that it would cause atrophy kind of symptoms in that leg.... let me know if it makes sense

[ArchivalUser]

i think its D- coz muscle is not used- so protein degradation. besides a its a reversible atrophy. i.e. once the person is ambulatory- he gains it back.
in case of mitochondrial damage- its an irreversible process.
Let me know if its correct

[ArchivalUser]

sorry its dd

matrix metalloproteinases (MMPs) are a family of enzymes with
proteolytic activity toward a number of extracellular
matrix (ECM) components; they are inhibited by tissue
inhibitors of MMPs (TIMPs).
in disuse atrophy there is imbalance btw these two proteins.
http://digitum.um.es/xmlui/bitstream/102...se.pdf.txt

[ArchivalUser]

@thisis B is found in Smooth muscles

@SOOHia thanx awesome explanation