Final answer:
When Golgi tendon organs are stimulated, they inhibit muscle contraction to protect the muscle from damage. They play a crucial role in proprioception by sensing changes in muscle tension and initiating a reflex that prevents excessive contraction.
Step-by-step explanation:
When Golgi tendon organs are stimulated, contraction of the associated muscle is inhibited. Golgi tendon organs serve as a proprioceptive sensory receptor organ that senses changes in muscle tension. They are activated when the muscle contracts too strongly and provide feedback to the nervous systaem, which in turn inhibits further muscle contraction to prevent potential damage to the tendons and muscles. This process is vital for maintaining muscle integrity and is known as the Golgi tendon reflex.
To briefly describe muscle contraction, the sliding filament model explains how muscles contract to cause movement. In this model, the neurotransmitter acetylcholine (ACh) is released at the neuromuscular junction (NMJ) and triggers an action potential that travels along the muscle fiber's membrane, the sarcolemma. This event is coupled with the release of calcium ions from the sarcoplasmic reticulum (SR). Calcium then binds to the troponin-tropomyosin complex on the actin filaments, allowing myosin heads to attach to the actin and pull the filaments toward the center of the sarcomere, thereby shortening the muscle fiber and generating movement.