yolk sac
Sign in to savemembranous sac attached to an embryo, formed by cells of the hypoblast adjacent to the embryonic disk
Key facts
- Carnegie stage
- 5b
- Precursor
- Endoderm
- Latin
- vesicula umbilicalis; saccus vitellinus
- Mesh
- D015017
- Te
- sac_by_E5.7.1.0.0.0.4 E5.7.1.0.0.0.4
via Wikipedia infobox
Research
10,612 papers- Yolk sac development, function and role in rodent pregnancy.Birth defects research · 2023
- Morphology of the avian yolk sac.Journal of morphology · 2021
- A review on yolk sac utilization in poultry.Poultry science · 2020
- Yolk-Sac Stage Bacteriome: Gaps of Knowledge and Demand for Fish Science.Current microbiology · 2025
- Origin and function of the yolk sac in primate embryogenesis.Nature communications · 2020
via PubMed
Wikidata facts
- Material used
- egg yolk
- Image
- Gray22.png
Show 1 more fact
- Commons category
- Yolk sacs
Sources (6)
via Wikidata · CC0
~5 min read
Encyclopedic overview
The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though yolk sac is far more widely used. The yolk sac is one of the fetal membranes and is important in early embryonic blood supply. In humans much of it is incorporated into the primordial gut during the fourth week of embryonic development.
In humans
Excerpted from Wikipedia’s “yolk sac” article, available under the CC BY-SA 4.0 licence.