Locomotion and Movement

Question 1

After contraction, what happens to the A, I, O bands, H-zone and M-line.

Answer 1

A=unchanged, I=shortened, O=lengthened, H-zone=almost diminished , M-line=disappear

Question 2

Myasthenia gravis

Answer 2

Mya=muscle, thenia=weakness, gravis=serious.
An auto immune disorder which makes antibodies against Na+ channels in sarcolemma inhibiting sliding of actin filament and causes fatigue.

Question 3

Muscular dystrophy

Answer 3

A genetic disorder, resulting in progressive degeneration of skeletal muscles.

Question 4

Parathyroid tetany

Answer 4

Caused due to low secretion of parathyroid hormone.
Results in hypocalcemia that leads to muscle cramps and numbness.