Question

Alpha-Gamma co-activation is the process whereby

Select one:

a. Contraction of extrafusal muscle fibres is accompanied by contraction of intrafusal fibres

b. The flexor withdrawal reflex is accompanied by the Crossed extensor reflex

c. Rhythmic movements of the limbs on both sides of the body occur

d. Muscle length and Muscle tension are monitored

e. Static and dynamic eleemnts of muscle stretch are monitored

Answer 1

Answer: a. Contraction of extrafusal muscle fibres is accompanied by contraction of intrafusal fibres.

Explanation: Alpha-gamma coactivation causes contraction of both extrafusal and intrafusal fibre. When there is stretching in muscle fiber or extrafusal fiber, it is sensed by muscle spindle or intrafusal fiber. Contraction of intrafusal fiber takes place through gamma motor neuron. This is sensed by extrafusal or muscle fiber, and it also contracts through alpha-motor neuron. This is alpha-gamma coactivation. Hence, option a) is correct. Other options are bogus in this context.