PAT 20A/B Lecture Notes - Lecture 4: Noxious Stimulus, Visceral Pain, Nociceptor

• School: Ryerson University
• Department: Pathotherapeutics
• Course: PAT 20A/B
• Professor: Janet O'Connell

Document Summary

Mechanisms of pain: first-order neurons, detect stimuli that threaten the integrity of innervated tissues, second-order neurons, process nociceptive information, third-order neurons, project pain information to the brain. Pain threshold: associated with the point at which a stimulus is perceived as painful (h&p 1264: the level of stimulus that results in the sensation of pain. Limbic system and ras also involved in perception. Neurons here extend into an area called the nucleus raphe magnus (nrm): axons of the nrm project to the dorsal horn of the spinal cord and inhibit pain transmission decreasing the perception of pain. Endogenous analgesic mechanisms: endogenously synthesized opioid peptides located in the peripheral processes of primary afferent neurons & other regions of the cns (pag, 3 endogenously synthesized opioid peptides, enkephalins, endophins, dynorphins. Types of pain: cutaneous and deep somatic pain, visceral pain, referred pain, acute pain, chronic pain, neuropathic pain.