Vertebrate striated muscles composed of twitch fibers are able to produce a graded contraction by
A)recruiting different numbers of motor units.
B)summing EPSPs in the motor end-plate region.
C)having excitatory and inhibitory input to a single muscle.
D)Vertebrate muscles are unable to produce graded contractions.

Question

Quizplus · Accepted Answer

Twitch fibers, also known as Type II fibers, can produce a graded contraction by recruiting different numbers of motor units. This means that the muscle can produce different levels of force depending on the number of motor units that are activated.

Vertebrate Striated Muscles Composed of Twitch Fibers Are Able to Produce