About 50 of sensory bers have nociocep5ve func5ons

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Unformatted text preview: on  ­ produces a warm feeling, swea5ng, reduces bowel ac5vity) •  Overall lethargy and lack of mo5va5on •  At high doses, seda5on occurs (overdose results in coma, unconsciousness, death) •  Combined with other depressants (e.g., alcohol) can be deadly (>50% of overdose cases involve alcohol) Transmission of Pain •  S5mulus Nocioceptors •  Nocioceptors are ~ 80% C fibers (unmyelinated – slow pain) and 20% A delta fibers (cold/pressure/ fast pain). •  About 50% of sensory fibers have nociocep5ve func5ons. •  C fibers are blocked in the presence of opiates. •  A delta fibers are unaffected by opiates Synaptic Arrangement of Dorsal Horn Descending Projections from Raphe' N. To Reticular Formation, Thalamus Dorsal Root Ganglion Excitatory Synapses Serotonin Serotonin From Nociceceptors Inhibitory Synapses Enkephalin Substance P and other transmitters Dynorphin or GABA Acute/Chronic Effects SYSTEM ACUTE CHRONIC CNS Analgesia Euphoria Sedation Cough sup...
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This note was uploaded on 03/21/2014 for the course COGS 174 taught by Professor Pineda during the Winter '11 term at UCSD.

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