[Campbell Biology P.1179] According to the text and Figure 50.33, what phenomenon occurs when... | Practice Question

According to the text and Figure 50.33, what phenomenon occurs when a skeletal muscle fiber is stimulated by a series of high-frequency action potentials without allowing complete relaxation between stimuli, resulting in a sustained, maximal contraction?

  • A: Single twitch.
  • B: Summation of twitches.
  • C: Recruitment.
  • D: Tetanus.

Explanation

The text explains that 'when the rate of stimulation is so high that the muscle fiber cannot relax at all between stimuli, the twitches fuse into one smooth, sustained contraction called tetanus.' Figure 50.33 clearly illustrates this by showing 'Series of action potentials at high frequency' leading to 'Tetanus'.