A text-book of pharmacology and therapeutics; or, The action of drugs in health and disease, . some indication of this action on thecord may occur, and in the feline group this stimulation involves notonly the cord, but also the motor areas of the brain. Respiration.—In man and in most other animals the respiration isslowed by morphine from the beginning^ (Fig. 13), and as the dose isincreased, the slowing becomes progressively greater. After smallquantities the breathing may be rather shallower, especially if sleepfollows; but as the rate slows the depth increases, though not suffi-ciently to
A text-book of pharmacology and therapeutics; or, The action of drugs in health and disease, . some indication of this action on thecord may occur, and in the feline group this stimulation involves notonly the cord, but also the motor areas of the brain. Respiration.—In man and in most other animals the respiration isslowed by morphine from the beginning^ (Fig. 13), and as the dose isincreased, the slowing becomes progressively greater. After smallquantities the breathing may be rather shallower, especially if sleepfollows; but as the rate slows the depth increases, though not suffi-ciently to compensate for the slowing, and the total air breathed mayfall to one-half the normal or less. The characteristic effect of morphineis thus a diminution in the rhythm of the centre, which remains sus-ceptible to reflex stimulation, but is unable to accelerate the dischargeof impulses to the same extent as normally. The inhalation of carbondioxide in unpoisoned animals quickens and deepens the respiration, butunder morphine, while it deepens it as much as before, it is unable to Fig. 13. Respiration of the cat. At M, injection of morphine intravenously. The respirationis immediately slowed and the movement is increased in depth. quicken it in the same measure. If morphine causes rest and sleep, lesscarbon dioxide is formed in the tissues and though less is excreted owingto the slowness of the breathing, there may be no accumulation in theblood and the depth of the respiration remains unchanged or may beshallower. But if the slowing is more marked, the gas accumulates inthe blood and acting on the respiratory centre deepens the breathing, asit cannot accelerate it except to a limited extent. In the later stages of morphine poisoning, the breathing often becomesirregular, and this irregularity may have a periodic character, a seriesof deep respirations being followed by several progressively weakerones and then by complete inactivity for several seconds. The breathingthen recom
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttherapeutics, bookyea
