Carnegie stage 8: Difference between revisions

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[[Category:Human Embryo]] [[Category:Carnegie Stage]]  [[Category:Carnegie Stage 8]] [[Category:Week 3]] [[Category:Carnegie Embryo 5960]]
[[Category:Human Embryo]] [[Category:Carnegie Stage]]  [[Category:Carnegie Stage 8]] [[Category:Week 3]] [[Category:Carnegie Embryo 5960]]
[[Category:Hill Embryo H159]]
[[Category:Hill Embryo H91]]

Revision as of 17:24, 25 August 2016

Embryology - 29 Mar 2024    Facebook link Pinterest link Twitter link  Expand to Translate  
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Introduction

Stage8 SEM1.jpg

Gastrulation is continuing as cells migrate from the epiblast, continuing to form mesoderm.

Mesoderm lies between the ectoderm and endoderm as a continuous sheet except at the buccopharyngeal and cloacal membranes. These membranes have ectoderm and endoderm only and will lie at the rostral (head) and caudal (tail) of the gastrointestinal tract.

From the primitive node a tube extends under the ectoderm in the opposite direction to the primitive streak. This tube forms first the axial process then notochordal process, then finally the notochord.

The notochord is a key to embryonic folding and regulation of ectoderm and mesoderm differentiation. It lies in the rostrocordal axis and the embryonic disc will fold either side ventrally, pinching off a portion of the yolk sac to form the lining of the gastrointestinal tract.

Summary

Human embryonic stage 8 occurs during week 3 between 17 to 19 days.

The embryo is now 1.0 - 1.5 mm in size.

Identify

  • embryonic disc
  • primitive node, primitive streak, primitive groove
  • connecting stalk
  • cut amniotic membrane

See also Events

Links: Week 3 | Gastrulation | Notochord | Lecture | Practical | Stage 9
Week: 1 2 3 4 5 6 7 8
Carnegie stage: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
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

Bright Field

Stage8 bf1.jpg Stage8 bf2.jpg Stage8 bf3.jpg

Scanning EM

Stage8 SEM1.jpg

Stage8 sem1.jpg Stage8 sem2.jpg Stage8 sem3.jpg Stage8 sem5.jpg Stage8 sem6.jpg Stage8 sem7c.jpg


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.

Embryonic Development

Kyoto Collection

Stage8 bf4.jpg

View: embryonic disc, showing the epiblast viewed from the amniotic (dorsal) side. Amniotic membrane removed, connecting stalk to the left.

Image source: Embryology page Created: 19.03.1999


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.

Carnegie Collection

Stage8 bf5.jpg

Dorsal view. Primitive node appears as a conspicuous opaque region with the notochordal process extending rostrally.

Stage8 bf6.jpg

Ventral view. Notochordal plate visible.

iBook - Carnegie Embryos  
link=http://itunes.apple.com/au/book/the-carnegie-staged-embryos/id510004473?mt=11 iTunes link
  • iTunes link | iBook Store
  • Description - Imagine the excitement of seeing this incredible early period of human development for the first time. Now consider that much of our initial understanding of human development is based upon study of historic embryo collections. You can now look at these historic images of the first 8 weeks after fertilisation and explore for yourself the changes that occur in human development during this key period. This current book is designed as an atlas of the Carnegie embryo stages with some brief notes and additional information covering the first 8 weeks of development. These images are from from the beginning of last century and are one of the earliest documented series of human embryos collected for basic research and medical education on development. I hope you enjoy learning about the amazing early events that begin to make and shape us. This is the second book in a series of educational releases from UNSW Embryology.
  • Release: First Edition - Mar 12, 2012 ISBN 978-0-7334-3148-7 Print Length 82 Pages, 25.8 MB Language English.
  • PDF Preview version 3.87 MB (Read the associated information, this is an edited educational preview version with many features not functioning).
  • The current website also includes numerous embryo images from this textbook (see Embryonic Development and Carnegie Embryos).

Serial Sections

Stage8 bf7.jpg
  • Notochordal process and notochordal canal. (detail)
  • Primitive pit. (detail)
  • Primitive groove and primitive streak. (detail)
Stage8 bf8.jpg
  • Prechordal plate.
  • Neural groove.
  • Notochordal process and notochordal canal.
  • Primitive pit.
  • Primitive groove and primitive streak.

Hill Collection

"Dobbin" Embryo  
Further descriptions of the "Dobbin" Embryo characterised as (Carnegie Stage 8) can be found in the following papers:

Hill JP. and Florian J. The development of head-process and prochordal plate in man (1931) J Anat. 65(2): 242-6. PMID 17104317

Hill JP. and Florian J. A young human embryo (embryo dobbin) with head-process and prochordal plate. (1931) Phil. Tran. Roy. Soc. London B, 219: 443-486.

Hill JP. and Florian J. Further note on the pro-chordal plate in man. (1931) J. Anat., 46: 46-47. PMID 17104356

Note the rostral end of notochordal process was at first mistaken for prechordal plate, see published correction.

See page - Carnegie Stage 8 - "Dobbin" Embryo


Stage 8 Links: Week 3 | Gastrulation | Lecture | Lecture | Somitogenesis | Lecture - Mesoderm | Lecture - Ectoderm | Lecture - Early Vascular | Science Practical | Carnegie Embryos | Category:Carnegie Stage 8 | Next Stage 9
  Historic Papers: 1920 Mateer Embryo | 1931 Head-Process | 1931 Prochordal Plate | 1931 neurenteric canal
HillH159 Stage 8 bf01.jpg HillH159 Stage 8 bf02.jpg
chorionic vesicle stereo view 1 chorionic vesicle stereo view 2
HillH159 Stage 8 bf03.jpg HillH159 Stage 8 bf04.jpg
embryo stereo view 1 embryo stereo view 2

Image source: The images from the Hill Collection (part of the Embryological Collection) are reproduced with the permission of the Museum für Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity. Images are for educational purposes only and must not be reproduced electronically or in writing without permission from the Museum für Naturkunde Berlin.

Links: Hill Collection

Events


References

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Additional Images

Historic Images

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



Cite this page: Hill, M.A. (2024, March 29) Embryology Carnegie stage 8. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_8

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G