Alteration in skeletal muscle function

Question 1

Which type of exercise stimulates hypertrophy?

Answer 1

High resistance exercise

Question 2

Disuse atrophy causes …….

Answer 2

Loss of contractile proteins -> Reduced fibre diameter -> Loss of power

Question 3

When does muscle atrophy begin?

Answer 3

Age 30

Question 4

What can exercise cause an increase in? (Possible 5 things)

Answer 4

• Z band width
• Volume of mitochondira
• ATPase
• Density of T tubule systems
• Number of contractile proteins

Question 5

What changes take place when muscle length increases?

Answer 5

Addition of sarcomeres, changes in neurology and viscoelastic properties

Question 6

What enzyme terminates ACh?

Answer 6

Acetylcholinesterase

Question 7

What is myastenia gravis?

Answer 7

It is the autoimmune destruction of the end-plate ACh receptors resulting in the loss of junctional folds at end plate and widening of synaptic cleft.

Question 8

What the symptoms of Myasthenia Gravis?

Answer 8

• Fatiguability and sudden falling

- Drooping upper eye lids and double vision

Question 9

How do you treat myasthenia gravis?

Answer 9

• Acetylcholinesterase inhibitors

- Immune suppressants

Question 10

Muscle fibres in DMD (Duchenne muscular dystrophy) can be described as …… and …..

Answer 10

Shrunken and dying

Question 11

Can you explain the consequence of the protein abnormality in DMD?

Answer 11

• Muscle fibres tear themselves apart on contraction
• Enzyme creatine phophokinase liberated into serum
• Calcium enters and caused necrosis
• Pseudohypertophy before fat and connective tissue replace muscle fibres

Question 12

What is Gower’s sign and in which type of muscular dystrophy is it seen?

Answer 12

It is the weakness of proximal muscles and is seen in DMD

Question 13

Can myofilament number increase or decrease? Or is the number constant?

Answer 13

It is dynamic