Which of these statements correctly describes twitch summation?

Question

Quizplus · Accepted Answer

Twitch summation occurs when a second stimulus is applied to a muscle fiber before it has completely relaxed from the first stimulus. This results in incomplete relaxation and a stronger contraction as the filaments are already partially activated. Option A is incorrect as the muscle fiber cannot be restimulated before the action potential has returned to resting potential. Option C is also incorrect as the strength of muscle contraction is dependent on several factors including the number of activated motor units and the frequency of stimulation, not just the strength of the action potential. Option D is also incorrect as stronger action potentials generally result in stronger muscle contractions unless there are other factors limiting the contraction.

Which of These Statements Correctly Describes Twitch Summation