273
Views
0
CrossRef citations to date
0
Altmetric
ARTICLE

The Allantois and Urachus: Histological Study Using Human Embryo and Fetuses

ORCID Icon, ORCID Icon, ORCID Icon, , ORCID Icon, & ORCID Icon show all
Pages 919-928 | Received 01 Jul 2021, Accepted 15 Nov 2021, Published online: 02 Dec 2021
 

Abstract

Introduction:

Relatively little is known about allantois and urachal development in early humans.

Design:

Serial sagittal histological sections from eight human embryos and fetuses were examined to determine allantois development.

Results:

At gestational age 6–7 weeks, the primitive allantois consists of an enlarged tube located between the umbilical cord and abdominal cavity, whereas the urachus is not yet developed. At 8 weeks, the allantois gradually withdraws from the distal to the proximal end of the umbilical cord, and both the proximal allantois and the rectum (hindgut) start to develop into the cloaca. At 10 weeks, the allantois was located mostly in the abdominal cavity.

Conclusion:

The urachus forms from the distal end of the allantois and develops into a closed fibrous cord between the base of the urinary bladder and the umbilicus. The urogenital sinus forms from the proximal end of the allantois.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is supported by the Beijing Municipal Administration of Hospitals (XTZD20180302).

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.