A system of obstetrics . e stalkof the allantois. A oro—ection of the cord in this stage isdiagram-matically represented in Fig. 58. As development progresses the umbilical cord becomes relativelylonger and narrower (Fig. ). The Bomatopleures, folding in moreand more until they meet at the nave] and close-in the ccelome, carrythe somatopleuric stalk with them until it ultimately comes into con-tad with the stalks of the umbilical vesicle and yelk-sac, and all fusetogether to make one solid cord traversed by the allantoic blood-vessels, THE EARLY STAGES OF DEVELOPMENT. 131 of which the arteries
A system of obstetrics . e stalkof the allantois. A oro—ection of the cord in this stage isdiagram-matically represented in Fig. 58. As development progresses the umbilical cord becomes relativelylonger and narrower (Fig. ). The Bomatopleures, folding in moreand more until they meet at the nave] and close-in the ccelome, carrythe somatopleuric stalk with them until it ultimately comes into con-tad with the stalks of the umbilical vesicle and yelk-sac, and all fusetogether to make one solid cord traversed by the allantoic blood-vessels, THE EARLY STAGES OF DEVELOPMENT. 131 of which the arteries wind in a spiral manner round the veins. Themesoblast of the somatic stalk becomes converted into jelly-like connec-tive tissue {jelly of Wharton), and binds all the rest together. A cross-section of the cord in this stage is represented in Fig. 59. From the structure and attachments of the umbilical cord it will beobvious that when it is severed at the navel at birth, the true amnion Flo- 58. Fig.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectobstetrics, bookyear1
