Human anatomy, including structure and development and practical considerations . es ismore fully considered in connection with the development of the diaphragm (page1701); for the present purpose it is sufiticient to note that the liver-anlage earlycomes into relation with the septum transversuni. Ihe ventral j)ortion of the pri-mary li\cr-evagination, clothed with the entoblastic lining f)f the gut-tube, very soondifferentiates into two diverticula : the one nearer the head, or hepatic division, pro-duces the liver proper; the other, or cystic division, later becomes the gall-bladderand its
Human anatomy, including structure and development and practical considerations . es ismore fully considered in connection with the development of the diaphragm (page1701); for the present purpose it is sufiticient to note that the liver-anlage earlycomes into relation with the septum transversuni. Ihe ventral j)ortion of the pri-mary li\cr-evagination, clothed with the entoblastic lining f)f the gut-tube, very soondifferentiates into two diverticula : the one nearer the head, or hepatic division, pro-duces the liver proper; the other, or cystic division, later becomes the gall-bladderand its duct. These divisions are gradually removed from the primiti\e duodenumby the growth of the primary diverticulum, which at one end becomes convertedinto a tube connected with the digestive canal and at the other bifurcates into thehepatic and cystic channels. This tube, evidently later the common bile-duct, is atfirst short and wide, but later rapidly lengthens. Fig. 1459. Septum transversumi%\ —Vi .:/.*» pV _Hei)atii-cii\ dliriilum Liver-anlageCystic diverticulum Cut-tube-. :4 \?J; l^C--Vi &-^^*^ * Portion of sagittal section of early rabbit embryo, showing liver-anlage and ducts. X 95. The cells lining the longer hepatic diverticulum undergo marked proliferationand produce the liver-mass which invades the septum transversum almost as far asthe sinus venosus and surrounds the vitelline veins. The formation of the liver-massfollows at first the type of development seen in tubular glands, outgrowths of thehepatic tube branching and subdividing to form solid sprouts and buds composed ofepithelial cells. In some of the lower animals, as the amphibians, the tubular typeis retained in the adult organ; but in the higher forms, including man, the tubularcharacter of the young liver is soon lost and replaced by the reticular arrangementproduced in consequence of the growing together and union of the terminal di\is-ions of the gland. Coincidently with the formation of the net-work of
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Keywords: ., bookauthormc, bookcentury1900, bookdecade1910, booksubjectanatomy
