. The clinical study of blood-pressure : a guide to the use of the sphygmomanometer in medical, surgical, and obstetrical practice, with a summary of the experimental and clinical facts relating to the blood-pressure in health and in disease . on ofthe blood, and have been ex-tensively studied. They maybe provoked by the stimula-tion of any afferent only such nerve in theentire body, stimulation ofwhich invariably lowersblood-pressure, is the depres-sor nerve. The fall, in thiscase, is due chiefly to a dilata-tion of the splanchnic ves-sels ; but not wholly, for somelowering occurs a
. The clinical study of blood-pressure : a guide to the use of the sphygmomanometer in medical, surgical, and obstetrical practice, with a summary of the experimental and clinical facts relating to the blood-pressure in health and in disease . on ofthe blood, and have been ex-tensively studied. They maybe provoked by the stimula-tion of any afferent only such nerve in theentire body, stimulation ofwhich invariably lowersblood-pressure, is the depres-sor nerve. The fall, in thiscase, is due chiefly to a dilata-tion of the splanchnic ves-sels ; but not wholly, for somelowering occurs after sectionof the splanchnic nerves. With this single excep-tion, stimulation of any cen-tripetal nerve as a rule raisesblood-pressure. This is easilyshown on stimulation of thecentral cut end of the sciatic,anterior crural, or other largenerve trunk, and similar re-flexes occur on irritation ofparts of the cerebral sensory nerves, however, contain some depressor fibres, forHowell * has shown that, if the sciatic is cooled to 0° C. central 1 Howell, Budgett, and Leonard. The Effect of Stimulation and of Changes ^in Temperature upon the Irritability and Conductivity of Nerve Fibres, Jour,of Physiol., 1894, vol. xvi, p. 298,. Fig. 5.—Eise in blood-pkessube pboducedby stimulation of the antekior cruralNERVE (pressor effect). Trace from dogs carotid. Tetanizing current. 22 BLOOD-PRESSURE IN THE NORMAL ANIMAL to the point of, stimulation, a fall in pressure replaces the ordi-nary rise. Similarly, Hunt ^ found, that, in the early period ofregeneration of the cut sciatic, only reflex vaso-dilatation fol-lows stimulation, the reflex constriction being obtained later,when the nerve has been more completely repaired. Mechan-ical stimulation of the skeletal muscles, and of the mucousmembrane of rectum and vagina, commonly results in a fall inpressure.^ According to Porter,^ this happens more readilywhen the animal is under ether, chloroform, or chloral, thanunder curare. Th
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbloodpr, bookyear1904
