Licence: In copyright
Credit: Arterial hypertonus, sclerosis and blood-pressure. Source: Wellcome Collection.
Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.
58/234 page 30
![may exist as to the probability of suclv a sensitiveness will be lost. IIYPERTONUS AND RELAXATION IN ATHEROMATOUS ARTERIES. As has been indicated in an earlier chapter the common conception of a sclerosed artery is that it is a rigid tube. This conception, as we have shown, was borrowed from the teaching regarding the vessels in advanced atheroma, and it is in accordance with experience that the extreme example be- comes the standard type. This common conception is, how- ever, erroneous, and seriously misleading. It is only in atheroma with much calcareous infiltration that the artery becomes practically a rigid tube. In my study of the arterial wall I liave frecpiently been surprised to find the amount of relaxation that took place in a vessel that was clearly the seat of much calcareous infiltration. In other cases where, from the hooped and segmented character of the thickenings, there seemed little doul)t that the thickenings were atheromatous, they could no longer be felt when the vessel became relaxed. In this latter class of case tlie character of the artery to the sense of touch is probably due to irregular thickenings of the intima plus hypertonic contraction, the tliickenings not being felt when the wall becomes soft, by the passing off of the hypertouus, or it may be due merely to irregularity in the muscular coat itself. In other cases tlie rigid segments persist, no matter wliat measures l)e taken for tlie removal of the liyjiertonic contraction; and yet in a consideralile number of sucb cases it is (piite jilain to tlie linger that a measure of relaxation can be effected. That lelaxation under such conditions occurs is du^ tip the anatomical fact, that in atheroma it is rare for the entire circumference of the vessel to be alfected; there is usually a consideralile iiart of it where there is only moderate thicken- ing of the tunica intima; and where the nmscular coat can relax and contract so as to a])])reciably affect the condition of the wall. The idea of the fixed and r'Kjul tube has to be given up, .save in extreme cases. That the recognition of such arterial changes is not duo to a personal delicacy of](https://iiif.wellcomecollection.org/image/b28036591_0058.jp2/full/800%2C/0/default.jpg)
