[Campbell Biology P.1179] Based on the information provided, what combination of neural contr... | Practice Question

Based on the information provided, what combination of neural control mechanisms would allow the nervous system to generate the most forceful possible contraction in a skeletal muscle?

  • A: Activating only small motor units at a low frequency of stimulation.
  • B: Recruiting all available motor units and stimulating the muscle fibers within each motor unit at a very high frequency to achieve tetanus.
  • C: Alternating activation among motor units to prolong contraction time, regardless of frequency.
  • D: Activating large motor units at a moderate stimulation frequency, allowing for some relaxation between twitches.

Explanation

The text explains two ways the nervous system regulates muscle contraction: 'controlling which motor units are activated' recruitment and 'varying the rate of muscle fiber stimulation.' To achieve the most forceful contraction, both mechanisms should be maximized: recruiting all available motor units especially large ones, though not explicitly stated for all, 'all available' implies it and stimulating them at a high frequency to induce tetanus, which is the sustained maximal tension.