Question

Aarons’s biceps muscle was damaged when his humerus bone broke. Several of the nerves innervating the muscle fiber were damaged or completely detached from the muscle. How would excitation-contraction coupling be affected in Aaron's muscle fibers that are no longer innervated by an a-motor neuron?

Answer 1

Loss of motor neuron innervation by biceps muscle causes decreased excitation - contraction coupling because, muscle is not stimulated and no release of calcium so no excitation and contraction coupling.

The affects of loss of innervation are

i) Fasciculations ( muscle twitching)

ii) Muscle atrophy

iii) Hypotonia

iv) muscle paralysis