Which statement is true about alpha and gamma motor neurons?

• A. They work together but have separate functions
• B. They always function independently
• C. They only function in the brain
• D. They do not coordinate with intrafusal fibers

Answer: (A)

This question is about how the motor system coordinates muscle contraction with sensory feedback from muscle spindles. Alpha motor neurons drive extrafusal muscle fibers to produce force, while gamma motor neurons stimulate the intrafusal fibers inside the muscle spindle to keep the spindle sensitive to stretch. For smooth, coordinated movement, these two systems are activated together in a process called alpha-gamma coactivation. This arrangement lets the muscle contract and at the same time maintains the spindle’s ability to detect changes in length, so reflexes and proprioceptive feedback remain accurate even as the muscle shortens. Because they have distinct roles but operate in concert, the true statement is that they work together but have separate functions. They do not operate independently, they do coordinate with intrafusal fibers, and they function in the spinal cord as part of motor control, not only in the brain.