What does the Golgi tendon organ (GTO) primarily respond to?

The Golgi tendon organ (GTO) is a specialized proprioceptive structure located at the junctions of muscles and tendons. Its primary function is to sense changes in muscle tension and the force exerted by muscle contractions. When a muscle generates tension during contraction, the GTO is activated and sends signals to the central nervous system to help regulate muscle activity and prevent potential injury due to excessive force.

This ability to detect tension is crucial for maintaining balance between opposing muscle groups and ensuring safe levels of exertion during physical activities. The information provided by the GTO contributes to reflexive responses, which can include inhibiting muscle contraction if the tension is too high, thereby protecting the muscles and tendons from damage.

In contrast to the GTO, other options focus on different aspects of muscle or joint function that do not align with the specific role of the Golgi tendon organ. Changes in muscle length relate to muscle spindles, and changes in joint angle pertain to other proprioceptors that monitor joint position rather than muscle tension. Changes in muscle mass do not directly engage the GTO, as the organ is concerned with the forces experienced by tendons and muscles during activity.