358 VEGETABLE DKTiaS 



Opium and Moephine. 



The action of morphine and opium is practically the 

 same, with some exceptions to be noted. 



Action External. — Opium may be absorbed to a slight 

 extent from the unbroken skin, and causes a mild, anodyne 

 action. Absorption readily occurs from mucous membranes 

 and raw surfaces, with resulting characteristic effects. 



Action Internal. — Digestive Tract. — Opium diminishes 

 the two principal activities of the digestive organs, namely, 

 secretion and motion. Secretions all over the body are 

 decreased, except that of sweat. The action upon the ali- 

 mentary tract in lessetiiug secretion, is partly a local one 

 and partly constitutional, following the absorption of the 

 drug. The mouth is made dry, thirst is increased and appe- 

 tite impaired. Opium is absorbed rather slowly from the 

 stomach and bowels, and stimulates the splanchnic nerve 

 centre of the sympathetic system, which inhibits the move- 

 ments of the stomach and intestines, and thus lessens peri- 

 staltic action of these organs. Opium is directly opposed 

 to belladonna in this respect, as the latter drug paralyzes 

 the intestinal inhibitory apparatus (splanchnic endings), and 

 so increases peristalsis. 



In diminishing both secretion and motion, opium causes 

 constipation in health, but is most useful in relieving 

 vomiting and diarrhoea. In toxic doses, opium may induce 

 diarrhoea from paralysis of the splanchnic inhibitory centre. 



Blood and Elimination. — Morphine circulates in the 

 blood as such. The greater part of opium is decomposed 

 in the body, a portion being destroyed by the liver, while 

 some is probably burned up in the blood. The smaller 

 part is eliminated, chiefly by the kidneys, but also in the 

 other secretions. It is found in the gastric juice after hypo- 

 dermic injection, and therefore washing out the stomach 

 assists elimination and recovery in opium poisoning. 



Nervous System. — The most important action of opium 

 is exerted upon the nervous system. It is necessary to 



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