title: Possible explanation for analgesia mediated by direct spinal effect of morphine.
mesh_terms: D003864:Depression, Chemical; D006801:Humans; D007275:Injections, Intravenous; D009020:Morphine / Q000008:administration & dosage* / Q000037:antagonists & inhibitors; D009270:Naloxone / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects*; D010148:Intractable Pain / Q000188:drug therapy*; D012018:Reflex / Q000187:drug effects; D012023:Reflex, Monosynaptic / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects*
chemical_list: D009270:Naloxone; D009020:Morphine