A manual of midwifery : including the pregnancy and the puerperal state / by Karl Schroeder ; translated into English from the third German edition by Charles H. Carter.

  • Schroeder, Karl Ludwig Ernst, 1838-1887.
Date:
1873
Catalogue details

Licence: Public Domain Mark

Credit: A manual of midwifery : including the pregnancy and the puerperal state / by Karl Schroeder ; translated into English from the third German edition by Charles H. Carter. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    abdomen becomes the vitelline sac. Just as the intestines are derived from two layers, namely, the inner germinal or intestinal glandular layer and the intestinal fibrous layer, the inferior lamella of the divided lateral plates, so also the vitelline sac is formed of an internal epithelial and an external connective-tissue layer, which contains the omphalo-mesenteric vessels of the first foetal vascular system. The more the abdominal cavity closes the more the intestinal canal and vitelline sac are separated from each other, and their communication 1 »ecomes restricted. But the vitelline vesicle does not grow, its vessels atrophy, and finally the intestinal canal onected only by a narrow duct, which later also atrophies— ductus omphalo-entericus—with the atrophied vitelline vesicle. Ac- cording to Schultze, this can almost always be seen (140 times in 150 cases) in the mature human afterbirth, as a whitish vesicle situated 1 »etween the amnion and the chorion, to which sometimes a white cord derived from the funis goes, namely, the ductus omphalo- entericus. 5. The Allantois Before the amniotic cavity has perfectly closed, two slight eleva- tions are formed at the margin of the entrance to the cavity containing the pelvic intestines. These two elevations, solid origi- nally, soon become blended into one, and a cavity forms in it. The vesicle thus formed is provided with a pedicle, and is very early supplied with vessels from the ends of both primitive aortae. The vesicle connected by the hollow pedicle with the intestine passes between the amnion and the vitelline sac to the periphery of the ovum, and supplies the epithelial layer of the chorion with a connective tissue, a vascular substratum. In describing the chorion it was stated that the vessels of the decidua refiexa atrophy, except at the place for the placenta where they continue to develop abundantly, and become the agents for the exchange of blood between the mother and the foetus. The allantois, therefore, has the important function of carrying the two umbilical arteries to the periphery of the ovum, to allow of the formation of the placenta. The part of the allantois enclosed in the abdominal cavity then becomes the urinary bladder and the urachus, which is afterwards obliterated, and fomis the middle ligament of the bladder. Id the accompanying diagrams wo give a concise graphic description of the gradual process of the formation of the membranes of the ovum. Fig. 3. Fio. 1.