BMS 870 Lecture Notes - Lecture 18: Thermoreceptor, Posterior Grey Column, Raphe Nuclei
24 Dec 2017
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Document Summary
Pain: nociceptors - free, branching unmyelinated nerve endings that signal damage. Types: mechanical, thermal, chemical: difference bw pain and nociception. Pain - sensation of sore, aching, throbbing sensation. Nociception - sensory process that provides signals to trigger pain. Nociceptors and transduction of painful stimuli: ion channels opened by: Strong mechanical stimulation, t extremes, o2 depriv, chemicals. Substances released by damaged cells: proteases, atp, k+ ion channels, histamine (causes membrane depolarization + vessel leak: hyperalgesia - altered threshold lvl for pain (lower), increased pain sensations. Primary (injured area) + secondary (areas outside injured site: inflammation - in response to inflamm agents: glutamate, serotonin, adenosine, atp. Pain, heat, redness, swelling: hot and spicy. Capsaican activates trpv1 channel + has analgesic properties (reduces pain) as it depletes substance p. Bradykinin - depolarize nociceptors + make heat-activated nociceptors more sensitive. Prostaglandings - result from lipid-membrane breakdown = increased pain sensitivity.
