Difference between revisions of "Carnegie stage 1"

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==Introduction==
 
==Introduction==
 
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Human early zygote showing male and female pronuclei
 
Human early zygote showing male and female pronuclei
 
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File:Early_zygote_labelled.jpg|Early zygote labelled
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File:Early_zygote.jpg|Early zygote
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File:Early_zygote_labelled.jpg|Early zygote labeled
 
File:Stage1 size with ruler.jpg|Stage 1 size with ruler
 
File:Stage1 size with ruler.jpg|Stage 1 size with ruler
 
File:Human_zygote_two_pronuclei_01.jpg|Human zygote two pronuclei<ref name="PMID20579351"><pubmed>20579351</pubmed>| [http://www.rbej.com/content/8/1/77 Reprod Biol Endocrinol.]</ref>
 
File:Human_zygote_two_pronuclei_01.jpg|Human zygote two pronuclei<ref name="PMID20579351"><pubmed>20579351</pubmed>| [http://www.rbej.com/content/8/1/77 Reprod Biol Endocrinol.]</ref>

Revision as of 08:15, 25 October 2011

Introduction

Early zygote labelled.jpg

Human early zygote showing male and female pronuclei

The early human zygote where the male and female pronuclei (centre of image) have not yet combined to form the single zygote nucleus. These pronuclei are the nuclei from the spermatozoa (sperm) and oocyte (egg) and contain all the nuclear genetic material (chromosomes, DNA, genes).

Two of the egg's polar bodies (right, 3 o'clock position of image) are shown at the edge of the egg cytoplasm. These polar bodies contain the excess DNA from the meiotic divisions of the egg.

The zona pellucida (edge of image) forms a specialised thick extracellular matrix layer around both the egg and the developing conceptus for the first week.

Mitochondria in the cytoplasm contain additional genes and in humans these mitochondrial genes are entirely derived from the oocyte.

Facts: Week 1, size 0.1-0.15 mm

Features: zygote, fertilized oocyte, pronuclei, polar bodies, zona pellucida


Links: Week 1 | Zygote | Zona pellucida | Mitosis | Genetics | Human Genome | Mitochondrial Genome | Lecture | Medicine Practical | Science Practical | Stage 2
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

Carnegie stage 1

References

  1. 1.0 1.1 1.2 1.3 <pubmed>20579351</pubmed>| Reprod Biol Endocrinol.
  2. <pubmed>19924284</pubmed>
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. (2020, November 29) Embryology Carnegie stage 1. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_1

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