A text-book of practical therapeutics . ause of scarlet-red skin ofbelladonna poisoning. In poisonous doses it causes a fall of arterial pressure due tocentric vasomotor palsy and depression of the muscular coats ofthe bloodvessels, but there is no direct cardiac depression, as hasbeen generally taught, for Reichert has proved that the drug is nota heart-depressant unless the dose is simply overwhelming. Some-times when belladonna is given the pulse becomes slow, but in thesecases the slowing is due to temporary stimulation of the peripheralvagi or to momentary depression of the cardiac motor
A text-book of practical therapeutics . ause of scarlet-red skin ofbelladonna poisoning. In poisonous doses it causes a fall of arterial pressure due tocentric vasomotor palsy and depression of the muscular coats ofthe bloodvessels, but there is no direct cardiac depression, as hasbeen generally taught, for Reichert has proved that the drug is nota heart-depressant unless the dose is simply overwhelming. Some-times when belladonna is given the pulse becomes slow, but in thesecases the slowing is due to temporary stimulation of the peripheralvagi or to momentary depression of the cardiac motor ganglia. (SeeFigs. 16 and 17.) 1 If a homely simile, found useful by the writer in teaching, may be used, the inhibi-tory centers may be represented by a schoolmaster and the motor and sensory centersby two boys. The escape of chloroform in the room paralyzes them all, but, finally,the boys recover before their master and go off as truants (convulsions); at last themaster (inhibitory centers) recovers and order, or health, is Fig. 16.—A, atropine depressesthe peripheral vagi and stimulatesthe accelerator nerves (C). BELLADONNA 145 Respiration.—Atropine is a stimulant to the respiratory centerin ordinary amounts, but recent careful studies show that its highreputation as a respiratory stimulant is not based either on clinicalor experimental evidence. In many cases it fails to increase therespirations at all, and it is certainly inferior to caffeine and strych-nine in the treatment of opium poisoning. In large doses it is adepressant and paralyzant to respiration, and produces death fromrespiratory failure due to paralysis of the motor nerves supplyingthe respiratory muscles, and probably by depressing the respiratorycenter. \fViWVV^ ii in rv vWW^AAAAA^JV^^,^
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttherape, bookyear1922
