{"term":{"id":"16261","title":"alveolar period","longtitle":"IUPAC Gold Book - alveolar period","doi":"10.1351\/goldbook.16261","code":"16261","status":"current","synonym":"<em>synonym<\/em>: alveolar phase","definitions":[{"id":1,"text":"Phase in lung development beginning in utero (about \\(\\pu{32}\\) to \\(\\pu{36}\\) weeks in the human fetus) and lasting until about eight years of age.","notes":{"1":"In this phase, the terminal alveolar saccules subdivide several more times, giving rise to the mature alveoli."},"links":[{"term":"alveoli","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/10359"},{"term":"in utero","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/10862"}],"sources":["PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 719 (https:\/\/doi.org\/10.1515\/pac-2015-1202)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/16261\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/16261\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/16261\/plain"},"citation":"Citation: 'alveolar period' 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.16261","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.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","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":"2026-07-14T10:45:34+00:00"}}