Carnegie stage 18: Difference between revisions

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* [[Sensory - Hearing and Balance Development|'''Hearing''']] - otic capsule precartilaginous. Semicircular ducts form in the order anterior, posterior, and lateral from thickened epithelial areas and adjacent epithelial layers fuse. Cochlear duct is now L-shaped. First pharyngeal arch bar begins to chondrify (Meckel’s cartilage), second arch may chondrify (Reichert’s cartilage), stapes and stapedius commence. Auricular hillocks merge to form auricle primordia.
* [[Sensory - Hearing and Balance Development|'''Hearing''']] - otic capsule precartilaginous. Semicircular ducts form in the order anterior, posterior, and lateral from thickened epithelial areas and adjacent epithelial layers fuse. Cochlear duct is now L-shaped. First pharyngeal arch bar begins to chondrify (Meckel’s cartilage), second arch may chondrify (Reichert’s cartilage), stapes and stapedius commence. Auricular hillocks merge to form auricle primordia.
* [[Musculoskeletal System - Bone Development Timeline|'''Bone''']] - lower limb femur and tibia chondrification of cartilage template.<ref name=“PMID9185992”><pubmed>9185992</pubmed></ref>  
* [[Musculoskeletal System - Bone Development Timeline|'''Bone''']] - lower limb femur and tibia chondrification of cartilage template.<ref name=“PMID9185992”><pubmed>9185992</pubmed></ref>  
 
* [[Cardiovascular System - Coronary Circulation Development|'''Cardiovascular''']] - Coronary circulation connection of the proximal coronary arteries to the aorta.<ref name=PMID3286038><pubmed>3286038</pubmed></ref>


===References===
===References===

Revision as of 12:55, 25 August 2016

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

Stage18 bf1c.jpg

Facts

Week 7, 44 - 48 days, 13 - 17 mm

Gestational Age GA - week 9

Summary

  • Ectoderm: sensory placodes, lens pit, otocyst,nasal pits moved ventrally, fourth ventricle of brain
  • Mesoderm: heart prominence
  • Head: 1st, 2nd and 3rd pharyngeal arch, forebrain, eye, auricular hillocks
  • Body: heart, liver, umbilical cord
  • Limb: upper and lower limb buds, foot plate, wrist, hand plate with digital rays

See also Events

Features

  • Development indices: number of semicircular ducts (1-3) and length of the paramesonephric duct.
  • Identify: pigmented eye, eyelid, nasolacrimal groove, external acoustic meatus, heart, digital rays, liver prominance, thigh, ankle, foot plate, umbilical cord


Links: Week 7 | System Development | Lecture - Limb | Lecture - Head Development | Lecture - Sensory | Science Practical - Head | Science Practical - Sensory | Science Practical - Urogenital | Category:Carnegie Stage 18 | Stage 19
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

Stage18 bf10.jpg Stage18 bf11.jpg
Embryo in gestational sac Embryo open sac
Stage18 bf12.jpg Stage18 bf13.jpg
Embryo with placentation (ectopic) Embryo in amniotic sac
Stage 18 Links: Embryo in gestational sac | Embryo open sac | Embryo 2 and gestational sac | Embryo 2 | Carnegie stage 18


Embryo Virtual Slides

Stage 18 - Right Lateral

Stage18 bf11.jpg

 ‎‎Mobile | Desktop | Original

Stage 18 | Embryo Slides
Stage 18 - Left Lateral

Stage18 bf12.jpg

 ‎‎Mobile | Desktop | Original

Stage 18 | Embryo Slides

Scanning EM

Stage18 em01.jpgStage18 em11.jpg

Ventral view of head showing upper lip, maxilla and nasal region.

Image Source: Prof Virginia Diewert

Kyoto Collection

Stage18 bf1.jpg

View: This is a dorsolateral view of embryo. Amniotic membrane removed.

Image source: Embryology page Created: 19.03.1999

Human stage18 face 01.jpg

Ventral view of head region (1 mm scale).


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

Stage18 bf2.jpg Stage18 bf3.jpg Stage18 bf4.jpg Stage18 bf5.jpg

Stage18 bf6.jpg Stage18 bf7.jpg Stage18 bf8.jpg Stage18 bf9.jpg


Carnegie stage 18: Right | Anterior | Posterior | Left | Right | Anterior | Posterior | Left


Carnegie Collection Embryos - Stage 18 
Serial No. Size (mm) Grade Fixative Embedding Medium Plane Thinness (µm) Stain Semi. ducts P.-M. duct (mm) Year Notes
109 E., 12.0* Ch.,30 Poor Alc. P Transverse 20 Al. coch. 1 0.4 1897 Tubal Least—advanced third
144 E., 16.0* Ch, 40x30x30 Good Formalin P Sagittal 40 Al. eoch. 3 0.85 1899 Most—advanced third
175 E., 13.0 Ch, 30x25x25 Poor Alc. P Transverse 20 Al. coch. 2 0.6 1900 Tubal Partly macerated
296 E., 17.0 Poor Ale. P Coronal 20 Various 3 0.85 1905 Most—advanced third
317 E., 16.0 Good Formalin P Coronal 20 (Stain - Haematoxylin Eosin) or. G. 2 0.7 1905 Middle third
351 E.,14.0* Good Formalin P Coronal 250 Slightly carmine— 2 038 1904 Injected (Berlin blue)
406 E., 16.0 Ch., 40x40x40 Good Formalin P Sagittal 20 (Stain - Haematoxylin Eosin) 3 0.7 1907 Operative. Most—advanced third
423 E., 15.2 Good Formol—Zenker P Transverse 50 Carmine 3 0.85 1904
424 E., 172 Good Formalin P Transverse 50 Carmine 3 10 1904 Double infection. Advanced
492 E, 16.8 Ch, 40 x 40 Exc. Zenker P Coronal 40 Al. coch. v 3 0.7 1911 Injected (India ink)
511 E., 160* Ch., 3?* 32x32 Good Ale. P Sagittal 40 Al. coch. 3 1.1 1911 Head injured. Most advanced in group
670 E, 12.5 Poor Ale. P Sagittal 50 (Stain - Haematoxylin Eosin) 3 10 1913 Tubal Advanced
719 E, 15.0 Ch, 50x50x50 Good Formalin P Trans 40 Al. coch. 2 0.6 1913 Median in group
733 E., Ch., 4Sx40x2S ISO Poor Formalin P Sagittal 50 Al. coch. 2 0.6 1913 Median in group
841 E. 15.0 Ch., 18 x 16x9 Good Formalin P Coronal & Trans, 20 10 (Stain - Haematoxylin Eosin), carmine 2 0.32 1914 Operative. Head cut separately
899 E, 160* Ch. 50 x 18 x IS Good Bouin P Sagittal S0 Al. coch. 3 0,65 1914 Tubal Head injured
991 E. l?.0 Good Formalin P Sag so R, V, Gieson 3 0.9 1914 Advanced
1909 E., 14.6 Good Formalin P Coronal 20 Al. coch,or. G. 1 0.3 1917 Less advanced
2673 E.,15.5 Good Formalin P Transverse 40 Al. coch. 2 0.52 1919 Median in group
4430 E., 14.0 Ch, 51 x40x21 Exc. Corros. acetic P Transverse 15 Al. coch,or. G. 3 0.9 1923 Most—advanced third
5542B E., 16.0 Ch, 37x32x25 Good Formalin P Transverse 40 Al. coch. 2 0.7 1927 Other twin abnormal
5747 E, 15.2 Ch, 32x27x25 Poor Alc.—formol P Sagittal 25 Al. coch. 2 0.25 1928 Least—advanced or middle third
5935A E, 13.5 Ch, 40x30x30 Good Formalin P Coronal 40 Al. coch. 1 0.38 1929 Other twin stunted
6522 E, 13.2* Good Corros. acetic C—P Coronal 10 Al. coch. 3 0.8 7 Middle or most—advanced third
6524 E, 11.7* Exc. Corros. acetic C—P Transverse 10 Al. coch. 1 0.4 ? Least—advanced third
6525 E, 13.8* Exc. Corros. acetic C—P Sagittal 8 Al. coch. 2 0.42 ? Weak staining
6527 E, 14.4* Exc. Corros. acetic C—P Transverse 15 Al. coch. 2 0.67 ? Mechanical damage
6528 E, 13.4* Exc. Corros. acetic C—P Coronal 8 Al. coch. 1 0.33 ? Least—advanced third
6529 E, 15.6* Good Corros. acetic C—P Coronal 10 Al. coch. 2 0.4 .5 Middle third
6533 E, 12.5* Good Corros. acetic C—P Sagittal 6, 8, 10 Al. coch. 2 0.45 ? Middle third
6551 E, 18.0 Poor Formalin p Coronal 40 (Stain - Haematoxylin Eosin) 3 0.8 1932 Tubal
7707 E, 14.5 Ch ,37x32 Exc. Bouin C—P Transverse 10 (Stain - Haematoxylin Eosin), phlox. 2 0.54 1939 Operative. Middle third
8097 E, 15.5 Ch, 37x25x21 Good Formalin C—P Transverse 10 (Stain - Haematoxylin Eosin) 1 0.19 1942 Least advanced in group
8172 E, 16.5 Exc. Bouin C—P Transverse 20 (Stain - Haematoxylin Eosin) 3 0.58 1943 Operative. Very advanced
8235 E, 14.0* Good Bouin C—P Sagittal 10 (Stain - Haematoxylin Eosin) Mallory 2 0.25 1944 Tubal
8355 E, 15.0 Ch, 23 Exc. Formalin C—P Coronal 10 Azan 1946 Tubal. Duplicated spinal cord caudally
8812 E, 12_9 Exc Formalin C—P Transverse 10 (Stain - Haematoxylin Eosin) 1950 Rubella. Medical abortion. Midbrain punctured
8945 E, 13.9 Good Zenker p Transverse 8 Borax, carm. 1952 Univ. Chicago No. H 1254
9107 E, 17.0 Ch, 38x28x22 Good Bouin p Transverse 15 Borax, carm. 1918 Univ. Chicago No. H 516
9247 E, 15.0 Exc. Bouin C—P Sagittal 8 Azan 1954 Tubal
Abbreviations
  • Size - E. is the greatest length of the embryo and Ch. is the mean diameter of the chorion.
  • Grade - total grade of the specimen and includes both its original quality and the condition of the mounted sections.
  • Embedding medium - paraffin (P) or a combination of celloidin and paraffin (C-P).
  • Fixative - formalin (Formol), alcohol and formalin (Alc, formol), Bouin (Bouin solution)
  • Stain -
  • ? - unknown or not determined.
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).

Hill Collection

HillH6 Stage 18 bf05.jpg HillH6 Stage 18 bf04.jpg HillH6 Stage 18 bf03.jpg HillH6 Stage 18 bf02.jpg
right ventral right ventrolateral right ventrolateral right lateral
HillH6 Stage 18 bf51.jpg HillH6 Stage 18 bf06.jpg HillH6 Stage 18 bf01.jpg
right ventral (smaller) left lateral (smaller) right dorsolateral (smaller)
Links: Hill Collection


Events

  • Vision - Mesenchyme invades the region between the lens epithelium and the surface ectoderm.[1]
  • Hearing - otic capsule precartilaginous. Semicircular ducts form in the order anterior, posterior, and lateral from thickened epithelial areas and adjacent epithelial layers fuse. Cochlear duct is now L-shaped. First pharyngeal arch bar begins to chondrify (Meckel’s cartilage), second arch may chondrify (Reichert’s cartilage), stapes and stapedius commence. Auricular hillocks merge to form auricle primordia.
  • Bone - lower limb femur and tibia chondrification of cartilage template.[2]
  • Cardiovascular - Coronary circulation connection of the proximal coronary arteries to the aorta.[3]

References

  1. <pubmed>7364662</pubmed>
  2. <pubmed>9185992</pubmed>
  3. <pubmed>3286038</pubmed>

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 18. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_18

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