On the comparative anatomy of the lymphatics of the mammalian urinary bladder / by George Hoggan and Frances Elizabeth Hoggan.

Hoggan, George.

Date:: [1881]

Credit: On the comparative anatomy of the lymphatics of the mammalian urinary bladder / by George Hoggan and Frances Elizabeth Hoggan. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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$any special system of valveless collecting lymphatics, as seen in other tissues, on the other hand, suggest a limited function for the lymphatics of the bladder, a function confined to taking up at once the lymph or serum exuded from those great blood- vessels, and thus preventing it from passing into the bladder through the sodden epithelial cells which line it, while at the same time there are no collecting lymphatics close to that sur- face for the purpose of acting as the draining adjuncts to that area as in the case of the submucous lymphatics of the intestinal canal, lest from their position they might also drain off material from the cavity of the bladder injurious to the organism. Although immediately underneath the epithelial lining of the bladder there is a very thin layer or network of blood capillaries, yet that layer is almost too insignificant in normal conditions to cause an exudation of lymph or serum into the bladder, or to require an arrangement on its deep surface to carry away the minute quantity of lymph exuded from the plexus. This con- dition may explain, on the one hand, why there appears to be little or no perceptible absorption from the vesical cavity in normal conditions, but great absorption in inflamed conditions, where absorption would be probably due to and confined to the distended bloodvessels, and not to the lymphatics at all, and, on the other hand, why in cases of cystitis the amount of albumen to be found in the urine seems to be excessively great in pro- portion to the amount of pus contained in it. It appears also probable to us that the lymphatics of the bladder represent a condition which, if it cannot exactly be called a rudimentary type, might at least be called an instance of arrested development. We have found that in embryonic life, as a rule, the lymphatics are represented to a great extent only by those vessels which afterwards become the special efferent lymphatics of tissues and organs, and that, as growth progresses, we have a continuous development from the peripheral extremities of these existing lymphatics of the special collecting and generally valveless lymphatics. This continuous develop- ment in the lymphatics does not even cease when the adult state has been attained, but becomes more plentiful as age advances, as may be well seen in studying the collecting reser- \oirs on tbe lower surface of the diaphragmatic musculature in$