Mechanoreceptors respond to which stimuli?

• A. Detect chemical levels in the blood
• B. Respond to touch, pressure, vibration, stretch, and itch
• C. Detect light and color
• D. Detect temperature and pain

Answer: (B)

Mechanoreceptors are specialized sensors that respond to mechanical energy—the forces that deform or move tissue. They detect touch when the skin is contacted, pressure from a weight or garment, vibration from mechanical waves, and stretch when muscles or skin are elongated. This mechanical stimulation opens force-sensitive ion channels in the receptor, generating a receptor potential that can trigger an action potential and carry the signal to the brain. Other options refer to different sensory systems: chemical levels in the blood are detected by chemoreceptors, light and color by photoreceptors, and temperature and pain by thermoreceptors and nociceptors. So, the defining stimuli for mechanoreceptors are mechanical forces such as touch, pressure, vibration, and stretch, which is why this option is correct.