Difference between revisions of "Carnegie stage 5"

From Embryology
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| valign="top"| '''Facts:''' Week 1 - 2, size 0.1 - 0.2 mm  
 
| valign="top"| '''Facts:''' Week 1 - 2, size 0.1 - 0.2 mm  
  
'''Features:''' implantation completed, inner cell mass, bilaminar embryo, trophoblast development
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'''Features:''' implantation completed, inner cell mass, bilaminar embryo, trophoblast development.
  
 
* The '''conceptus''' completes implantation during this stage.  
 
* The '''conceptus''' completes implantation during this stage.  
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:'''Links:''' [[Week 2]] | [[Implantation]] | [[Lecture - Week 1 and 2 Development|Lecture]] | [[2011_Lab_2|Practical]] [[Carnegie_stage_6|Stage 6]]
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:'''Links:''' [[Week 2]] | [[Implantation]] | [[Lecture - Week 1 and 2 Development|Lecture]] | [[2011_Lab_2|Practical]] | [[Carnegie_stage_6|Stage 6]]
 
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Revision as of 06:14, 25 October 2011

Introduction

Stage5 bf11L.jpg Facts: Week 1 - 2, size 0.1 - 0.2 mm

Features: implantation completed, inner cell mass, bilaminar embryo, trophoblast development.

  • The conceptus completes implantation during this stage.
  • The trophoblast cells (syncytiotrophoblast and cytotrophoblast) proliferate. Syncytiotrophoblast cells continue to invade the maternal endometrium and cytotrophoblast cells form clumps that will later form sites of chorionic villi formation.
  • The maternal endometrium locally begins the decidual process and the endometrial stroma accumulates fluid (edematous).
  • The extraembryonic cavities begin to form.
  • The bilaminar embroyonic disc forms from the inner cell mass (embryoblast).

Stage5 bf22L.jpg


Links: Week 2 | Implantation | Lecture | Practical | Stage 6
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
File:Chorion 001 icon.jpg</wikiflv>

Animation (left) shows the events following implantation and focuses on changes in the the spaces surrounding the embryonic disc, the extraembryonic coelom.

The blastoceol cavity is converted into two separate spaces: the yolk sac and the chorionic cavity.

The third space lies above the epiblast, the amniotic cavity.

blue - epiblast layer
yellow - hypoblast layer
red cells - extraembryonic mesoderm layer
green - trophoblast layer
red spaces - blood-filled spaces, maternal lacunae
white cells - (left) endometrial gland (right) endometrial epithelium
Quicktime movie

Stage 5a

Stage 5b

Stage 5c

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

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2020, April 6) Embryology Carnegie stage 5. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_5

What Links Here?
© Dr Mark Hill 2020, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G