Difference between revisions of "File:Bailey502.jpg"

From Embryology
 
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Some of the chorionic villi float freely in the blood spaces of the maternal placenta floating villi; others are attached to the maternal tissue fastening villi. The villi are separated into larger and smaller groups or lobules by the growth of connective tissue septa from the maternal placenta down into the decidua basalis. These are known as placental septa, while the groups of chorionic villi are known as cotyledons (Figs. 500 and 502).
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Both decidual cells and chorionic villi are important from a diagnostic standpoint, as the finding of them in curettings or in a uterine discharge may be accepted as proof of pregnancy.
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During the early months of pregnancy first four months the decidua basalis has essentially the same structure as the decidua parietalis. Its surface epithelium disappears very early, perhaps even before the attachment of the ovum. The glandular elements and the connective tissue undergo the same changes as in the decidua parietalis and here also result in the differentiation of a compact layer and a spongy layer. Both layers are much thinner than in the decidua parietals.
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As already noted, connective tissue septa pass from the superficial layer of the decidua basalis down into the foetal placenta subdividing the latter into cotyledons. At the margin of the placenta the decidua basalis passes over into the thicker decidua parietalis and here the chorion is firmly attached to the decidua basalis.
  
 
{{Template:Bailey 1921 Figures}}
 
{{Template:Bailey 1921 Figures}}
  
 
[[Category:Human]] [[Category:Placenta]] [[Category:Birth]] [[Category:Third Trimester]]
 
[[Category:Human]] [[Category:Placenta]] [[Category:Birth]] [[Category:Third Trimester]]

Latest revision as of 12:44, 6 June 2012

Fig. 502. Placenta at birth, seen from the uterine side

Bonnet.

Some of the chorionic villi float freely in the blood spaces of the maternal placenta floating villi; others are attached to the maternal tissue fastening villi. The villi are separated into larger and smaller groups or lobules by the growth of connective tissue septa from the maternal placenta down into the decidua basalis. These are known as placental septa, while the groups of chorionic villi are known as cotyledons (Figs. 500 and 502).

Both decidual cells and chorionic villi are important from a diagnostic standpoint, as the finding of them in curettings or in a uterine discharge may be accepted as proof of pregnancy.

During the early months of pregnancy first four months the decidua basalis has essentially the same structure as the decidua parietalis. Its surface epithelium disappears very early, perhaps even before the attachment of the ovum. The glandular elements and the connective tissue undergo the same changes as in the decidua parietalis and here also result in the differentiation of a compact layer and a spongy layer. Both layers are much thinner than in the decidua parietals.

As already noted, connective tissue septa pass from the superficial layer of the decidua basalis down into the foetal placenta subdividing the latter into cotyledons. At the margin of the placenta the decidua basalis passes over into the thicker decidua parietalis and here the chorion is firmly attached to the decidua basalis.


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Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

Reference

Bailey FR. and Miller AM. Text-Book of Embryology (1921) New York: William Wood and Co.



Cite this page: Hill, M.A. (2020, April 1) Embryology Bailey502.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Bailey502.jpg

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current00:47, 2 February 2011Thumbnail for version as of 00:47, 2 February 2011751 × 547 (74 KB)S8600021 (talk | contribs){{Template:Bailey 1921 Figures}} Category:Coelom Category:Placenta