Proprioceptors provide information about which aspects of the body?

• A. External temperature
• B. Light levels
• C. Muscle state; body position
• D. Chemical composition of blood

Answer: (C)

Proprioceptors are specialized sensory receptors that report the state of the musculoskeletal system, giving the brain a sense of where the body parts are and how they’re moving. They detect how stretched a muscle is (muscle spindles), how much tension is in a tendon (Golgi tendon organs), and the angles and movements within joints (joint receptors). This proprioceptive feedback lets you coordinate your movements and maintain balance even with eyes closed. External temperature is sensed by thermoreceptors, light levels by photoreceptors, and the chemical composition of blood by chemoreceptors—different systems that provide information about the environment or internal chemistry, not about muscle state and body position.