. 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 . ood passing through their vessels. This, ofcourse, is provided by a dilatation of the arteries throughoutthe gland. Such a general dilatation of the small arteries inany vascular area causes a fall in lateral pressure in the mainartery supplying it. If the area be of sufficient extent, and isnot compensated for by vaso-constriction in other vasculardistr
. 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 . ood passing through their vessels. This, ofcourse, is provided by a dilatation of the arteries throughoutthe gland. Such a general dilatation of the small arteries inany vascular area causes a fall in lateral pressure in the mainartery supplying it. If the area be of sufficient extent, and isnot compensated for by vaso-constriction in other vasculardistricts, a fall in mean aortic blood-pressure follows. On theother hand, the total end pressure in the smallerarteries is increased by their dilatation, sinceless energy is lost in overcoming friction central to them,and, what is most important, when certain clinical methodsare considered, the maximum systolic pressurerises markedly. That this must be so is obvious fromBernards experiment, in which the pulse, ordinarily imper-ceptible in the smallest arteries, beciame evident even in the Bernard, Claude; Legons sur les liquides de Iorganisme. Paris, 1859,vol. i, pp. 310-311; vol. ii, p. 375. Quoted by Tigerstedt, Lehrbuch, pp. 494and FACTORS DETERMINING BLOOD-PRESSURE 21 vein. ^ The mechanism by which this variation in vasculartonus is brought about is a reflex one, either constrictor ordilator action being stimulated or inhibited, in response to astimulus reaching the local, spinal, or bulbar centres along acentripetal nerve. Vaso-motor tone, both local and general, ismarkedly affected by reflexes of remote vascular reflexes areof great significance for thegeneral blood-pressure, a swell as for the distribution 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
Size: 1208px × 2069px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectbloodpr, bookyear1904
