Human anatomy, including structure and development and practical considerations . ttached dorsally to the gut-tube, while its lateral expansionsform the floor of the pleural cctlom. This imperfect partition, the septum trans-vcrsum of His, also affords i)assa_t;e for the two ducts of Cuvier, formed on each sideby the union of the ])rimitive juiL^ular and cardinal veins, to i^ain the sinus venosus ;the septum transversum receives the hepatic outgrowth from the ])rimitive duodenum,which soon develops a conspicuous liver-mass within the substance of the rapid increase in the mass of th
Human anatomy, including structure and development and practical considerations . ttached dorsally to the gut-tube, while its lateral expansionsform the floor of the pleural cctlom. This imperfect partition, the septum trans-vcrsum of His, also affords i)assa_t;e for the two ducts of Cuvier, formed on each sideby the union of the ])rimitive juiL^ular and cardinal veins, to i^ain the sinus venosus ;the septum transversum receives the hepatic outgrowth from the ])rimitive duodenum,which soon develops a conspicuous liver-mass within the substance of the rapid increase in the mass of the developinj^ liver is attended by great thicken-ing of the septum transversum, particularly towards its dorsal edge. Coincidentlywith this augmentation, the septum differentiates into a thinner upper and a thickerlower stratum, the former constituting the floor of the pericardial cavity and sur-rounding the ducts of Cuvier, the latter enclosing the liver. Fig. 1436. Trachea Pericardial sac Septum transversum Loop of smallintestine extend-ing into cordVitelline vessels Communicationbetween pleuraland peritoneal sacs Suprarenal body Aorta ?^^T«*.o| Wolffian bodyMesogastrium Reconstruction of human embryo of 17 mm. vertex-breech length. X 14. {Mall.) The subsequent development of the liver is attended by progressive, althoughonly partial, separation of the inferior layer from the superior stratum of the septumtransversum, the latter layer remaining as the primitive, but still imperfect, dia-phragm between the pleuro-pericardial and peritoneal divisions of the dorsal attachment of the septum transversum, at first high in the cervical region,gradually recedes tailward. On reaching the level of the fourth cervical segment thefourth myotome is prolonged into the upper layer of the septum to supply musculartissue to what now becomes the diaphragm. The latter, however, is still incompletedorsally, owing to the existence on each side of the communication betwee
Size: 1564px × 1598px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthormc, bookcentury1900, bookdecade1910, booksubjectanatomy
