Selected monographs.

Date:: 1888

Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs. Source: Wellcome Collection.

93/440 (page 77)

observer takes up witli regard to tlie effect of mere changes of pressure, will lie be inclined to claim the right of laying stress upon the influence of derangement of nutrition, at an early or late period, for the purpose of explaining the disturb- ance of function. It is only in estimates of extreme con- ditions that certainty can be attained, and we shall not go wrong in laying down the two following propositions : First, that no considerable disturbance of the nutrition of the tissues can take place if the supply of blood be inter- rupted for a very brief period only, say for a few seconds, and during no portion whatever of the time in a complete manner ; or if a retardation of the circulation be moderate in extent and slow and gradual in its development, so that, as already mentioned (page 58), the tissues accommodate them- selves to the diminished blood-supply. Secondly, that if the circulation be completely interrupted for- several hours or days, severe disturbance of the nutrition of the tissue must necessarily ensue. The third form of renal congestion, viz. that which is due to impeded escape of urine, occurs in the human subject, though less frequently than the other forms. A comparison, however, cannot be so freely instituted between the sym- ptoms at the bedside in these cases and those produced by experiment, because for the most part only one kidney is affected, so that the urine, secreted by the healthy kidney alone, either presents nothing abnormal, or, if, the discharge from the affected kidney be not completely suspended, the result is a mixture of normal with abnormal urine. Another fact which affects the comparison is that the obstacles to escape of urine are usually of such a character that abnor- mal admixtures, e.g. albumen or blood, become superadded to the fluid after it has left the kidney. Instances of this kind are, among others, the obstacles due to concretions which irritate the mucous membrane, tumours in the urinary passages, &c. We have also no knowledge of the anatom- ical appearances of the human kidney from the very first stages of the process involving complete stagnation of urine, which can be compared with the result of tying the ureter; we likewise know nothing as to the part in which albumen is deposited in these kidneys.