Which of the following sensory receptors can induce muscle relaxation when activated?

The most suitable choice for a sensory receptor that can induce muscle relaxation when activated is the Golgi tendon organs. These receptors are located in the tendons and play a crucial role in sensing tension within the musculotendinous unit. When muscle tension becomes excessive, the Golgi tendon organs detect this increase and send signals to the central nervous system.

This feedback leads to a protective mechanism called autogenic inhibition, where the muscle experiencing tension is inhibited, allowing it to relax. This process is vital for preventing injury during high levels of muscle exertion.

While the Ruffini endings do provide sensory information related to joint position and may play a role in proprioception, they do not primarily induce muscle relaxation. Pacinian corpuscles are more related to detecting vibratory sensations and pressure rather than muscle tension and relaxation. Muscle spindle fibers, on the other hand, are responsible for detecting stretch within the muscle and typically contribute to muscle contraction rather than relaxation in a reflexive manner. Thus, Golgi tendon organs are identified as the sensory receptors that facilitate muscle relaxation through their function in monitoring and regulating muscle tension.