In the context of proprioceptors, what do muscle spindles primarily monitor?

• A. Blood oxygen content within skeletal muscle capillaries
• B. Changes in muscle tension generated at the tendon
• C. Changes in muscle length (stretch) and the rate of stretch
• D. Skin temperature and nociceptive (pain) stimuli

Answer: (C)

Verified step by step guidance

1. Understand that proprioceptors are sensory receptors that provide information about body position and movement to the central nervous system.
2. Identify the different types of proprioceptors: muscle spindles, Golgi tendon organs, and joint receptors, each monitoring different aspects of muscle and joint status.
3. Focus on muscle spindles, which are specialized sensory receptors located within the belly of skeletal muscles.
4. Recognize that muscle spindles primarily detect changes in muscle length (stretch) and the rate at which the muscle length changes, providing feedback for muscle control and coordination.
5. Differentiate muscle spindles from Golgi tendon organs, which monitor muscle tension, and from other receptors that detect blood oxygen or skin stimuli, confirming that muscle spindles do not monitor blood oxygen content or skin temperature.