. A text-book of comparative physiology for students and practitioners of comparative (veterinary) medicine . cut anywhere gives rise to aflow of blood, owing to sec-tion of some of these tubes,which, it will be remembered,are not visible to the unaidedeye. It is estimated that theirunited area is several hun-dred (500 to 800) times that ofthe arteries. If we suppose the epithe-lial lining pushed out of asmall artery we have, so faras structure alone goes, agood idea of a capillary—i. e.,its walls are but one cellthick, and these cells thoughloug are extremely thin, sothat it is quite easy to
. A text-book of comparative physiology for students and practitioners of comparative (veterinary) medicine . cut anywhere gives rise to aflow of blood, owing to sec-tion of some of these tubes,which, it will be remembered,are not visible to the unaidedeye. It is estimated that theirunited area is several hun-dred (500 to 800) times that ofthe arteries. If we suppose the epithe-lial lining pushed out of asmall artery we have, so faras structure alone goes, agood idea of a capillary—i. e.,its walls are but one cellthick, and these cells thoughloug are extremely thin, sothat it is quite easy to under-stand how it is that the amoe-boid corpuscles can, undercertain circumstances, pushtbeir way through its proba-bly semi-fluid walls. From what has been said,it will be seen that the wholecollection of vascular tubesmay be compared to two inverted funnels or cones with the. Fig. 189.—Various layers of the walls of asmall artery (Landois). e, endothelium;i. e, internal elastic lamina; c. m, circu-lar muscular fibers of the middle coat;c. t, connective tissue of the outer coat,or T. adventitia.
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1890
