Muscle Ageing

Question 1

Strength loses appear greater for lower body ;

Answer 1

40% decline in lower body

33% decline in upper body

Question 2

What is the average rate of muscle mass lost after 40 years old

Answer 2

8% per decade until 70 where it increases to 15%

Question 3

What atrophy’s more type 1 or type 2 fibres

Answer 3

Type 2

Question 4

What is the consequence of losing motor units

Answer 4

Results in muscles fibres becoming denervated

This can cause fibre atrophy and potential fibre loss

Question 5

How does denervation and collateral reconnection alter muscle characteristics

Answer 5

1.Increases myosin isoforms.
2. Decreases force output and velocity of contraction

Reinsertion of fibres:
1.increase motor unit
2. Preserves some muscle mass