Extra MSK phys

Question 1

Define osteoporosis

Answer 1

Low bone density which presents with fractures (T score < -2.5)

WORSE

Question 2

define Osteopenia

Answer 2

Decreased bone density (T score -1 > n > -2.5)

Question 3

Define Osteomalacia

Answer 3

Poor bone mineralisation

Question 4

Describe sliding filament theory of muscular contractin

Answer 4

• Depolarisation of the neuromuscular junction occurs, causing an influx of
  calcium ions into the sarcoplasm from the sarcoplasmic reticulum (1).
• Calcium binds to troponin C which causes a conformational change to the
  structure that moves tropomyosin away from the myosin head (1).
• The myosin head forms a cross-bridge with actin, allowing a ‘power-stroke’
  pulling the actin past the myosin towards the M line
• During the power-stroke, the myosin head bends, releasing ADP and
  phosphate (1)
• ATP binds to the myosin head, causing it to uncouple from the actin, allowing
  the process to repeat (1).
• ATP is hydrolysed to ADP and Phosphate, returning myosin to its normal
  position. (1)

Question 5

What nerve supplies the muscle of the the thenar eminence? When can they be affected?

Answer 5

median nerve. It can be affected in carpal tunnel syndrome