Carnegie stage 23: Difference between revisions

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:'''Links:''' [[Hill Collection]]
:'''Links:''' [[Hill Collection]]
==Madrid Collection==
{| class="wikitable mw-collapsible mw-collapsed"
! colspan=7| [[Madrid Collection|Madrid Collection Embryos]]  
|-bgcolor="CEDFF2"
! colwidth=100px|Carnegie<br>Stage
! colwidth=150px|Embryo
! colwidth=100px|Days
! colwidth=100px|CRL (mm)
! Section<br>thickness
! Staining
! Section plane
|-
| [[Carnegie stage 23|23]] || Mes-2 || 56 || 27 || 10  || {{HE}}-trichrome || frontal
|-bgcolor="F5FAFF"
| [[Carnegie stage 23|23]] || C11 || 57 || 28 || 10 || {{HE}}-trichrome || transverse
|-
| [[Carnegie stage 23|23]] || Bot 4 || 58 || 29 || 10 || Bielschowsky {{HE}} || transverse
|-bgcolor="F5FAFF"
| [[Carnegie stage 23|23]] || CA 4 || 59 || 31 || 10 || {{HE}} || frontal
|}


==Events==
==Events==

Revision as of 16:17, 31 January 2017

Embryology - 28 Mar 2024    Facebook link Pinterest link Twitter link  Expand to Translate  
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Introduction

Stage23 bf1c.jpg

This is the final Carnegie stage of embryonic development in Week 8. After this development is considered fetal for the remainder of the pregnancy.

Facts

Week 8, 56 - 60 days, 27 - 31 mm

Gestational age GA week 10

Summary

  • Ectoderm:
  • Mesoderm: ossification continues
  • Head: eyelids, external ears, rounded head
  • Body: straightening of trunk, intestines herniated at umbilicus
  • Limbs: hands and feet turned inward


See also Carnegie stage 23 Events

Features

  • scalp vascular plexus, eylid, eye, nose, auricle of external ear, mouth, shoulder, arm, elbow, wrist, toes separated, sole of foot, umbilical cord
  • hearing - cochlea shows nearly 21/2 turns. otic capsule cartilage separated from the semicircular ducts by a pre cartilaginous zone. Labyrinth has practically completed its gross development and ductus reuniens is well defined.[1]


Links: Week 8 | System Development | Lecture - Limb | Lecture - Head Development | Lecture - Sensory | Science Practical - Head | Science Practical - Sensory | Science Practical - Urogenital | Category:Carnegie Stage 23 | Fetal Development


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

Kyoto Collection

Stage23 bf1.jpg

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

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

Stage23 bf3.jpg Stage23 bf4.jpg

Stage23 bf5.jpg Stage23 bf6.jpg

Stage23 bf9.jpg Stage23 bf10.jpg

Stage23 bf11.jpg Stage23 bf12.jpg


Carnegie stage 23: 4570 right | 4570 anterior | 4570 left | 4570 posterior | 4570 large right | 4570 large left | Rotation | Carnegie Embryos


Stage 23 Links: Week 8 | System Development | Lecture - Limb | Lecture - Head Development | Lecture - Sensory | Science Practical - Head | Science Practical - Sensory | Science Practical - Urogenital | Historic - Skull Development | Carnegie Embryos | Madrid Embryos | Category:Carnegie Stage 23 | Next Fetal Development
  Historic Papers: 1954 Stage 19-23


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

Hill HH12
HillH12 Stage 23 bf01.jpg HillH12 Stage 23 bf02.jpg
HillH12 Stage 23 bf03.jpg HillH12 Stage 23 bf04.jpg
Links: Hill Collection

Madrid Collection

Madrid Collection Embryos  
Carnegie
Stage
Embryo Days CRL (mm) Section
thickness
Staining Section plane
23 Mes-2 56 27 10 (Stain - Haematoxylin Eosin)-trichrome frontal
23 C11 57 28 10 (Stain - Haematoxylin Eosin)-trichrome transverse
23 Bot 4 58 29 10 Bielschowsky (Stain - Haematoxylin Eosin) transverse
23 CA 4 59 31 10 (Stain - Haematoxylin Eosin) frontal

Events

  • Vision
    • The retina comprises the pigmented layer, external limiting membrane, proliferative zone, external neuroblastic layer, transient fiber layer, internal neuroblastic layer, nerve fiber layer, and internal limiting membrane. Eyelids closure is complete (Note - shown as still open in the Kyoto embryo).[3]
    • The cornea now comprises the anterior epithelium and its basement membrane, the substantia propria, and the posterior epithelium (Streeter, 1951, fig. 18, and O’Rahilly, 1966, figs. 51 and 59).
    • Optic nerve a vascular canal is present and sheath in the more advanced specimens (O’Rahilly, 1966, fig. 55).
  • Joint - knee cavity, anterior cruciate ligament and posterior cruciate ligament present[4]
  • Hearing - Cochlear duct tip now points “downward” for the second time (fig. 19-6). The duct is coiled to nearly its final extent of 2½ turns.
  • Vomeronasal organ - A narrow canal is seen in the long, tapering duct. The sac is beginning to shrink and retrogress (fig. 19-9).
  • Submandibular gland - Lumina are found in many terminal branches of the duct (fig. 19-10). Orientation of the epithelial tree is beginning, and angiogenesis is commencing around the epithelium. A mesodermal sheath is beginning to form around the gland.
  • Renal - Metanephros secretory tubules are changing from short to long, and becoming more convoluted. The epithelium in some tubules is high. Renal tubules of fourth and fifth orders are present. Large glomeruli are numerous (fig. 19-12).
  • Humerus. All five cartilaginous phases are now present (Streeter, 1949, figs. 3 and 18).
  • Endocrine[5]
    • Pituitary - adenohypophysis loss of the stalk and lobules of epithelium project into the mesodermal component of the gland, and oriented epithelial follicles are present (Streeter, 1951, plate 2). Abundant angioblasts and capillaries are found.
    • Epiphysis - The pineal body has reached Stadium 5 of Turkewitsch (1933).[6]
    • Thymus - The cortex is well-developed, "true lobulation" has begun with the appearance of" fine superficial scallops," lymphocytes are present sparsely in the subcortical zone, and vessels are found within the thymus (Norris 1938).
    • Adrenal Cortex - It appears that C2 cells first enter the body of the gland at this stage. The pattern of the arterial supply is established. The cellular "capsule" is penetrated by arterial capillaries which join the sinusoids. Their points of entry give the surface of the gland an appearance of cobblestones. The zona glomerulosa is formed of CI and C3 cells. Cells from this zone and from the "capsule" migrate centrally into the cords.[7]
    • Adrenal Medulla - Nerve fibres and neuroblasts are first seen in the body of the gland. The paragangtion (M3) cells are beginning to multiply rapidly and, from 30 mm (stage 23) until birth, some are differentiating into chro- maffin cells.[7]


References

Additional Images

Historic Images

Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)
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 28) Embryology Carnegie stage 23. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_23

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