11317 IUPAC Gold Book - trilaminar embryo 10.1351/goldbook.11317 11317 current synonym: trilaminary blastoderm 1 Disc-like embryonic stage in which differentiation into three layers (endoderm, mesoderm, and ectoderm) has occurred. In the human embryo this occurs in the third week, following the onset of gastrulation. ectoderm https://goldbook.iupac.org//terms/view/10632 endoderm https://goldbook.iupac.org//terms/view/10659 gastrulation https://goldbook.iupac.org//terms/view/10750 mesoderm https://goldbook.iupac.org//terms/view/10944 PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 815 (https://doi.org/10.1515/pac-2015-1202) https://goldbook.iupac.org/terms/view/11317/html https://goldbook.iupac.org/terms/view/11317/json https://goldbook.iupac.org/terms/view/11317/plain Citation: 'trilaminar embryo' 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.11317 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. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . 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. 2026-06-21T04:55:30+00:00