Which best describes the role of the Golgi tendon organ when muscle tension becomes excessive?

• A. Increases muscle contraction to lift heavier
• B. Inhibits muscle contraction to prevent damage
• C. Adjusts muscle spindle length
• D. Triggers pain sensation

Answer: (B)

The main idea is autogenic inhibition by the Golgi tendon organ. The GTO lives in the tendon and detects when tension becomes excessive. When that happens, Ib afferent fibers carry the signal to the spinal cord, where they activate inhibitory interneurons that reduce the activity of the same muscle’s alpha motor neurons. The muscle then relaxes or contracts less, lowering force to protect the tendon and muscle from damage. This protective mechanism contrasts with the muscle spindle, which responds to stretch to modulate length and often increases contraction; the GTO’s job is not to adjust spindle length, and it does not primarily trigger pain. Thus the role described is to inhibit contraction to prevent damage.