Title: yolk sac
Long Title: IUPAC Gold Book - yolk sac
DOI: 10.1351/goldbook.11389
Status: current

Definition
Fluid-filled, membrane-bound pouch on the ventral side of the early embryo that provides nourishment until the circulatory system develops.

Related Terms
- membrane: https://goldbook.iupac.org//terms/view/11555
- ventral: https://goldbook.iupac.org//terms/view/11363

Source
- PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 822 (https://doi.org/10.1515/pac-2015-1202)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/11389/html
- json: https://goldbook.iupac.org/terms/view/11389/json
- xml: https://goldbook.iupac.org/terms/view/11389/xml

Citation: Citation: 'yolk sac' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.11389
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
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Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-04-18T00:00:49+00:00