A _________ is a pain receptor in the body.

• A. Nociceptor
• B. Baroreceptor
• C. Mechanoreceptor
• D. Photoreceptor

Answer: (A)

Pain receptors are known as nociceptors. They are specialized sensory neurons that detect potentially tissue-damaging stimuli, including extreme temperatures, strong mechanical forces, and chemical irritants. When activated, nociceptors transmit signals to the spinal cord and brain, producing the sensation of pain. Other receptor types serve different senses: baroreceptors monitor blood pressure, mechanoreceptors detect mechanical forces like touch and vibration, and photoreceptors respond to light in the retina. Thus, the term that best fits a pain receptor is nociceptor.