Final answer:
Pain is activity in a neural structure capable of leading to a sensation of pain. Nociception is the neural processing of injurious stimuli, and pain can be caused by harmful or harmless stimuli that mimic damaging stimuli.
Step-by-step explanation:
Pain is activity in a neural structure considered capable of leading to or contributing to a sensation of pain. Nociception is the neural processing of injurious stimuli in response to tissue damage. Pain can be caused by true sources of injury, such as contact with a heat source that causes a thermal burn, or by harmless stimuli that mimic damaging stimuli, such as contact with capsaicins found in peppers. Capsaicin molecules bind to a transmembrane ion channel in nociceptors and can be used as a topical analgesic.