Manual of human histology . erable;in man it is, on the average, 0-004—00055, 0-002—0-01 inextreme instances; the wdde vessels being more especiallyfound in the neighbourhood of the afferent and efferent veins,the narrowest in the interval between them. The meshes ofthe network correspond, of course, in form, with the hepaticcell-network, and are thence more elongated in the interiorof the hepatic islets, more rounded externally, whilst theirbreadth corresponds with that of the columns of the hepaticcells, being about 0-006—0-02. The hepatic veins e&sentially resemble the portal vein, inso far
Manual of human histology . erable;in man it is, on the average, 0-004—00055, 0-002—0-01 inextreme instances; the wdde vessels being more especiallyfound in the neighbourhood of the afferent and efferent veins,the narrowest in the interval between them. The meshes ofthe network correspond, of course, in form, with the hepaticcell-network, and are thence more elongated in the interiorof the hepatic islets, more rounded externally, whilst theirbreadth corresponds with that of the columns of the hepaticcells, being about 0-006—0-02. The hepatic veins e&sentially resemble the portal vein, inso far as they possess no valves, branch out at acute anglesand do not anastomose; their larger branches also receivenumerous minute vessels, but these lie isolated in specialcanals in the hepatic substance to which they are firmlyattached, whence they do not collapse when cut across, and,at least in their finer ramifications, possess no external in-vestment of connective tissue, which is indeed but very rudi- FiR. mentary, even in the largest trunks. The relations of theultimate branches of the hepatic vein, termed by Kiernanintra-lobular veins, and by Krukenberg, venee centrales lobu-lorum, are, however, totally different from those of the portal Fig. 223. Segment of a very successful injection of the hepatic veins of tlieRabbit, x 35. One vena-intralobiilaris is visible in its entire course, but onlythe radicles of the other. The capillaries of the lobules partly coalesce and, in oneplace, two venous radicles do so. THE LIVER. 129 ramuscules. These veins, which in Man are 0-012—0-03 indiameter, are best studied in some animal whose liver breaksnp into isolated lobules, as the Pig; after which Kiernan hasgiven his somewhat diagrammatic figure. If we here open asmall branch of the hepatic vein, polygonal areaj are descriedthrough the walls of the vessel—the outlines of those surfacesof the lobules which are turned towards the vein (fig. 218). A minute vein which, in
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Keywords: ., bookcentury1800, bookdecade1850, booksubjecthistolo, bookyear1853
