The strength or weakness of a skeletal muscle contraction depends on
A) only the number of motor units activated.
B) only the frequency with which motor units fire.
C) only the number of muscle fibers stimulated.
D) only the number of motor units activated and the frequency with which motor units fire.
E) the number of motor units activated, the frequency with which motor units fire, and the number of muscle fibers stimulated.

Question

Quizplus · Accepted Answer

The strength or weakness of a skeletal muscle contraction is determined by a combination of factors: the number of motor units activated (more units result in a stronger contraction), the frequency with which these motor units fire (higher frequency can lead to more sustained contractions and can recruit additional fibers through temporal summation), and the number of muscle fibers stimulated within each motor unit (more fibers contracting equals a stronger muscle contraction). These factors work together to modulate the force of muscle contractions.

The Strength or Weakness of a Skeletal Muscle Contraction Depends