ACTION OF BELLADONNA AND ATROPINE 379 



human patients) due to obstruction,* when all otlier means 

 failed. Conversely, it is, and has been, the common practice 

 to give atropine with morphine to prevent peristalsis in 

 peritonitis and with apparently satisfactory results. It is at 

 present impossible to reconcile these apparently conflicting 

 facts, but it is readily conceivable that the resultant of the 

 opposing actions of atropine on the bowels in either stimu- 

 lating peristalsis by depression of the inhibitory apparatus, 

 on the one hand, or, in lessening peristalsis by depression of 

 the muscle, on the other, may depend as much upon the 

 condition of the gut as upon the dosage, and that, according 

 to the physiological or pathological state, one or the other 

 of these opposing actions will preponderate. 



The action upon the inhibitory nerve of the heart is 

 similar to that exerted upon the inhibitory nerve of the 

 bowels. The pneumogastiic terminations are depressed in 

 the heart by moderate doses, while the heart muscle is 

 paralyzed by large quantities of belladonna. 



A like depressing influence is believed to be exerted 

 upon the efferent nerve endings of the un striped muscles of 

 the bladder, urethra, uterus and vagina, as well as upon the 

 muscles of these organs. Belladonna acts medicinally as 

 an antispasmodic in relation to the muscles. 



Respiration. — Small doses of atropine do not affect the 

 respiration. Large therapeutic doses make the respiratory 

 movements quicker and deeper, by stimulation of the 

 medullary and spinal respiratory centres. Fatal doses 

 produce respiratory failure and asphyxia, owing to paralysis 

 of the respiratory centre and the peripheral vagus fllaments 

 concerned with the respiratory movements. Belladonna also 

 paralyzes the peripheral fibres of the pneumogastric nerve in 

 the bronchial tubes and acts therapeutically as follows: 

 1. As a respiratory stimulant ; the drug is generally inferior 

 to strychnine in this respect. 2. As an; antispasmodic, by 



* It IS probable in these cases that the obstruction was due to 

 spasm, and not mechanical. 



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