A reference handbook of the medical sciences, embracing the entire range of scientific and practical medicine and allied science . rder in the peripheralganglia distributed along the course of the nervetrunks. Such a tone of peripheral origin wouldexplain the additional dilatation observed on stimu-lating vasodilator nerves to parts whose vasocon-strictor nerves had previously been divided. Fromwhat has been said it follows that the simplestefferent path along which the vasomotor impulsescan pass may be considered as buUt up of two neu-rones, one with its cell body in the central nervoussystem
A reference handbook of the medical sciences, embracing the entire range of scientific and practical medicine and allied science . rder in the peripheralganglia distributed along the course of the nervetrunks. Such a tone of peripheral origin wouldexplain the additional dilatation observed on stimu-lating vasodilator nerves to parts whose vasocon-strictor nerves had previously been divided. Fromwhat has been said it follows that the simplestefferent path along which the vasomotor impulsescan pass may be considered as buUt up of two neu-rones, one with its cell body in the central nervoussystem and the other in a sympathetic , however, the spinal vasomotor centers arexinder the control of the chief center in the medulla,the axis-cylinder processes of the cells of the bulbarcenter must come into relation with the spinal vaso-motor cells, and so the complete efferent path comesto include three nerve units. Vasomolor Reflexes.—The activity of the centersin the medulla and cord from which the vasocon-strictor and vasodilator fibers take their origin isdetermined in large measure by the impulses falling. Fig. 742.—Blood-pressure during Electrical Stimulation of the Depressor Nerve. To be read fromright to left. The time of stimulation is indicated by the vertical lines (—? = 10 seconds). into them along various afferent nerve channelsgiving rise to reflex vasomotion. The possibleafferent paths include practically every centripetalnerve in the body, those distributed to the vesselwalls not excepted; whUe the response may varyfrom a slight local effect in the region whence theafferent impulse started to a change involving anextensive vascular area sufficient to produce varia-tions in the general blood pressure. The localreflexes, such as the congestion of the skin on theapplication of warmth, are conunonly dilatations,although constrictions also occasionally result. Ofthe general reflexes those occurring in the greatsplanchnic area are perhaps the most f
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Keywords: ., bookauthorbuckalbe, bookcentury1900, bookdecade1910, bookyear1913
