How do muscle spindles and Golgi tendon organs differ?

Muscle spindles and Golgi tendon organs serve distinct roles in the muscle and proprioception system, with key differences in what they detect.

Muscle spindles are specialized sensory receptors located within the belly of muscles. They are primarily responsible for detecting changes in muscle length and the rate at which that length changes. This ability allows the central nervous system to monitor and regulate muscle stretch, which is crucial for posture and movement coordination.

On the other hand, Golgi tendon organs are located at the junction between muscles and their tendons. Their primary function is to sense tension in the muscles. When a muscle contracts, the Golgi tendon organs monitor the amount of force exerted by the muscle through its tendon. This feedback ensures that excessive force does not lead to injury, as it can trigger a reflex that inhibits muscle contraction if the tension is too high.

Therefore, the correct choice highlights the specific functions of each receptor: muscle spindles are concerned with detecting changes in muscle length, while Golgi tendon organs are focused on detecting changes in muscle tension. This distinction is essential for understanding how the body maintains balance, posture, and coordinated movements.