• Cite/Export
  Cite/Export

  Copy a citation

  APA (6th ed.)

  

  Chicago (Author-Date, 15th ed.)

  

  Harvard (18th ed.)

  

  MLA (7th ed.)

  

  Turabian (6th ed.)

  

  Export a citation

  Export to RefWorks   Export to EndNote / Reference Manager   Export to EasyBib   Cancel

  Note: Citations are based on reference standards. However, formatting rules can vary widely between applications and fields of interest or study. The specific requirements or preferences of your reviewing publisher, classroom teacher, institution or organization should be applied.
• Print
• E-mail
  E-mail

  All fields are required.

  The E-mail Address(es) field is required. Please enter recipient e-mail address(es).

  The E-mail Address(es) you entered is(are) not in a valid format. Please re-enter recipient e-mail address(es).

  You may send this item to up to five recipients.

  Enter recipient e-mail address(es): Separate up to five addresses with commas (,)

  The name field is required. Please enter your name.

  Enter your name: The subject field is required. Please enter the subject. Subject:

  The E-mail message field is required. Please enter the message.

  E-mail Message: I thought you might be interested in this item at http://www.worldcat.org/oclc/112374458 Title: Placentation in garter snakes. III. Transmission EM of the omphalallantoic placenta of Thamnophis radix and T. sirtalis. Publisher: ISBN/ISSN: 0362-2525 OCLC:112374458

  
  

  The ReCaptcha terms you entered were incorrect. Please try to match the 2 words shown in the window, or try the audio version.

  Cancel
• Share
• Permalink
  Permalink

  Copy this URL to link to this page:

• Write a review
• Rate this item:
• • 1
  • 2
  • 3
  • 4
  • 5

Placentation in garter snakes. III. Transmission EM of the omphalallantoic placenta of Thamnophis radix and T. sirtalis.

Author:	DG Blackburn; RL Lorenz
Edition/Format:	Article : English
Publication:	Journal of morphology, 2003 May; 256(2): 187-204
Database:	From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
Other Databases:	British Library Serials; ArticleFirst
Summary:	The omphalallantoic placenta is a complex organ that is unique to viviparous squamates. Using transmission EM and light microscopy, we examined this placenta in garter snakes in order to understand its structural organization and functional capabilities. The omphalallantoic placenta is formed from the uterine lining and the bilaminar omphalopleure, the latter of which is associated with the isolated yolk mass and allantois. A thin shell membrane separates the fetal and maternal tissues throughout gestation. The uterine epithelium contains cuboidal cells with large droplets or granules and appears to be secretory. Epithelium of the omphalopleure is specialized for absorption and contains cells with prominent microvilli and others with large cytoplasmic droplets or granules. The brush-border cells are rich in mitochondria and Golgi bodies and interdigitate extensively with adjacent cells, forming elaborate intercellular canaliculi. Their morphology is consistent with their proposed role in sodium-coupled water movement. During development, the isolated yolk mass becomes depleted as yolk droplets are digested by cells of the omphalopleure and allantois. However, the allantois does not fuse to or vascularize the inner face of the omphalopleure. Consequently, the distance between fetal and maternal circulatory systems remains large (about 250-300 microm), precluding efficient gas exchange and hemotrophic transfer. The morphology of the omphalallantoic placenta strongly suggests that it functions in nutrient transfer through uterine secretion and fetal absorption.  Read more...
Rating:	(not yet rated) 0 with reviews - Be the first.
Search this publication for other articles with the following words: