Carnegie stage 9: Difference between revisions
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Human embryonic stage 9 occurs during week 3 between 19 to 21 days. The embryo is now 1.5 to 2.5 mm in size and somites have begun to form and number between 1 to 3 somite pairs during this stage. | Human embryonic stage 9 occurs during week 3 between 19 to 21 days. The embryo is now 1.5 to 2.5 mm in size and somites have begun to form and number between 1 to 3 somite pairs during this stage. | ||
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[[File:Stage9 bf1.jpg|400px|caption|Stage 9 View 1]] [[File:Stage9 bf2.jpg|400px|caption|Stage 9 View 2]] | ! View 1 !! View 2 | ||
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| [[File:Stage9 bf1.jpg|400px|caption|Stage 9 View 1]] | |||
'''View 1''' - [[:File:Stage9 bf1.jpg|Large]] | [[:File:Stage9 bf1b.jpg|Medium]] | [[:File:Stage9 bf1b.jpg|Small]] | | [[File:Stage9 bf2.jpg|400px|caption|Stage 9 View 2]] | ||
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| '''View 1''' - [[:File:Stage9 bf1.jpg|Large]] | [[:File:Stage9 bf1b.jpg|Medium]] | [[:File:Stage9 bf1b.jpg|Small]] | |||
| '''View 2''' - [[:File:Stage9 bf2.jpg|Large]] | [[:File:Stage9 bf2a.jpg|Medium]] | [[:File:Stage9 bf2b.jpg|Small]] | |||
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==Scanning EM View== | ==Scanning EM View== | ||
Revision as of 13:34, 22 August 2009
Introduction
Human embryonic stage 9 occurs during week 3 between 19 to 21 days. The embryo is now 1.5 to 2.5 mm in size and somites have begun to form and number between 1 to 3 somite pairs during this stage.
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| View 1 - Large | Medium | Small | View 2 - Large | Medium | Small |
Scanning EM View
Dorsal View
Features: embryonic disc, primitive node, primative streak, primative groove, somites, neural groove, brain plate region, connecting stalk, cut edge of amnion
Facts: Week 3, 19 - 21 days, 1.5 - 2.5 mm, Somite Number 1 - 3
View 1: embryonic disc, showing the epiblast viewed from the amniotic (dorsal) side.
Events: Ectoderm - Neural plate brain region continues to expand, neural plate begins folding over the notochord. Mesoderm - segmentation of paraxial mesoderm begins (1 - 3 somite pairs), cardiac primordium forms
Identify: neural groove and neural folds, the mesoderm, which segments beside the neural groove to form somites but extends laterally to margin of embryonic disc lateral plate mesoderm, where it merges with the covering extraembryonic mesoderm.
The intra-embryonic coelom develops in the middle of the lateral plate mesoderm. Note amniotic ectoderm covered by extramebryonic mesoderm (empty spaces above and below the mesoderm are artefacts, as are the lateral folds in the ectoderm).
Ventral View
View 2: embryonic disc, showing the epiblast, connecting stalk and brain fold.
Image source: Embryology page Created: 19.03.1999
- Carnegie Stages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | About Stages | Timeline
Image Source: Scanning electron micrographs of the Carnegie stages of the early human embryos are reproduced with the permission of Prof Kathy Sulik, from embryos collected by Dr. Vekemans and Tania Attié-Bitach. Images are for educational purposes only and cannot be reproduced electronically or in writing without permission.
Image source: The Kyoto Collection images are reproduced with the permission of Prof. Kohei Shiota and Prof. Shigehito Yamada, Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan for educational purposes only and cannot be reproduced electronically or in writing without permission.
Cite this page: Hill, M.A. (2024, April 27) Embryology Carnegie stage 9. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_9
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G
