Carnegie stage 12

From Embryology
Revision as of 12:00, 4 August 2009 by MarkHill (talk | contribs) (New page: FFacts: Week 4, 26 - 30 days, 3 - 5 mm, Somite Number 21 - 29 View: Lateral view, day 26, 27 somites, Amniotic membrane removed. Stage 12 SEM Features: day 26, 27 somites, forebrain, s...)
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FFacts: Week 4, 26 - 30 days, 3 - 5 mm, Somite Number 21 - 29

View: Lateral view, day 26, 27 somites, Amniotic membrane removed.

Stage 12 SEM

Features: day 26, 27 somites, forebrain, site of lens placode, site of otic placode , stomodeum, 1st pharyngeal arch, 2nd pharyngeal arch, 3rdpharyngeal arch, heart prominence, somite

Identify: forebrain, site of lens placode, site of otic placode, stomodeum, 1st pharyngeal arch, 2nd pharyngeal arch, 3rd pharyngeal arch, heart prominence, somite

Next:

Events Ectoderm: Neural tube continues to close, Caudal neuropore closes, forebrain

Mesoderm: continued segmentation of paraxial mesoderm (21 - 29 somite pairs), heart prominence

Head: 1st, 2nd and 3rd pharyngeal arch, forebrain, site of lens placode, site of otic placode, stomodeum

Body:

heart, liver, umbilical, early upper limb bulge

Image source: Embryology page Created: 19.03.1999


Carnegie Stages Link

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About Carnegie Stages

Carnegie stages are named after the famous US Institute which began collecting and classifying embryos in the early 1900's. Stages are based on the external and/or internal morphological development of the embryo, and are not directly dependent on either age or size. The human embryonic period proper is divided into 23 Carnegie stages. Carnegie stages are based on the external and/or internal morphological development of the embryo, and are not directly dependent on either age or size. Criteria beyond morphological features include age in days, number of somites present, and embryonic length.

The Kyoto Collection images are reproduced with the permission of Prof. Kohei Shiota. Scanning electron micrographs of the Carnegie stages of the early human embryos are reproduced with the permission of Prof Kathy Sulik. Images are for educational tutorial/revision purposes and cannot be reproduced electronically or in writing without permission.

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Dr Mark Hill 2009, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G