What action do alpha motor neurons perform on muscle spindles?

Enhance your knowledge of the Lower Motor Apparatus with our Test. Prepare with our comprehensive study materials, including flashcards and multiple-choice questions, each accompanied by detailed explanations and hints. Boost your readiness for the exam!

Multiple Choice

What action do alpha motor neurons perform on muscle spindles?

Explanation:
Alpha motor neurons cause contraction of extrafusal muscle fibers, which makes the muscle shorten and move. The muscle spindle sits in the muscle, so when the surrounding muscle contracts and moves, the spindle is moved as well. The spindle’s sensitivity is adjusted mainly by gamma motor neurons, not by alpha ones, which is why actions like sensitizing, relaxing, or inhibiting the spindle aren’t the direct result of alpha motor neuron activity. In short, activating alpha motor neurons moves the muscle—and with it, the spindle—through contraction.

Alpha motor neurons cause contraction of extrafusal muscle fibers, which makes the muscle shorten and move. The muscle spindle sits in the muscle, so when the surrounding muscle contracts and moves, the spindle is moved as well. The spindle’s sensitivity is adjusted mainly by gamma motor neurons, not by alpha ones, which is why actions like sensitizing, relaxing, or inhibiting the spindle aren’t the direct result of alpha motor neuron activity. In short, activating alpha motor neurons moves the muscle—and with it, the spindle—through contraction.

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy