Nociception
In physiology, nociception /ˌnəʊsɪˈsɛpʃ(ə)n/, also nocioception (from Latin nocere 'to harm/hurt'), is the sensory nervous system's process of encoding noxious stimuli. It deals with a series of events and processes required for an organism to receive a painful stimulus, convert it to a molecular signal, and recognize and characterize the signal to trigger an appropriate defensive response.