Carnegie stage 23

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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 2.5 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]


Historic Embryology
Embryology History George Streeter In 1949 the embryologist George Streeter[2] used the replacement of cartilage within the humerus by bone marrow as an arbitrary definition of the embryo to fetus transition.
"If the onset can be recognized in a given specimen, that specimen is straightway classed as a fetus."



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


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.

Oral Cavity

Movies

Carnegie Stage 23 MRI movies
Stage23 MRI 3D01 icon.jpg
 ‎‎Embryo Surface
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Stage23 MRI 3D02 icon.jpg
 ‎‎Embryo CNS
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Stage23 MRI S02 icon.jpg
 ‎‎Sagittal Embryo
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Stage23 MRI T01 icon.jpg
 ‎‎Trans. Embryo
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Stage23 MRI C01 icon.jpg
 ‎‎Coronal Embryo
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Stage23 MRI S01 icon.jpg
 ‎‎Sagittal Head
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Stage23 MRI S04 icon.jpg
 ‎‎Sagittal GIT
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Stage 23 MRI Movies: Surface | Central Nervous System | CNS (labeled) | Sagittal | Sagittal (labeled) | Transverse | Transverse (labeled) | Coronal | Sagittal Head (labeled) | Sagittal GIT (labeled) | Carnegie stage 23


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


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




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



Carnegie Collection - Stage 23 
Serial No. Size (mm) Grade Fixative Embedding Medium Plane Thinness (µm) Stain Point Score Sex Year Notes
45 E,28 Ch, 40x35x20 Poor ? P Coronal/Transverse 50 Al. coch. 51.5 Female 1895
75 E,30 Good Alc. P Sagittal 50 Coch. 57 Male 1897
86 E,30 Good ? ? Coronal 50 Coch. Male 1897 May be an early fetus
100 E,27 Poor ? P Sagittal 50 Al. coch. 57.5 ? 1897
108 E, 28 (est.) Poor Piurosulph. acid P Sagittal 45 Borax carm. 52.5 Male 1897
227 E30 Ch, 60x40x20 Poor Formalin P Sagittal 50, 100 Al. coch. 54 Female 1903
417 E,32 Ch., 0x60x40 Good Formalin P Transverse 100 Al. coch. 58.5 Female 1907
756A E, 27 Ch. 60x45x35 Good Formalin P Coronal 50 Al. coch. 56 Male 1913
882 E , 28 Ch, 80x80x40 Good Formalin P Transverse 40 Multiple 53 8 1913
950 E, 29 Good Formol P Transverse 50 Al. coch. 54 Male 1914
1199 E.,26 Ch,, 60x40x30 Good Formalin C Coronal 40 (Stain - Haematoxylin Eosin) aur , or. G. 54.5 Male 1915
1535 E , 28 Ch. 50x45 x15 Poor Formalin P Transverse 40 (Stain - Haematoxylin Eosin) 495 Female 1916
1945 E., 27.3 Ch., 83x53x22.5 Good Formalin C-P Transverse 50 (Stain - Haematoxylin Eosin) aur., or. G. 48 Male 1917
2561 E., 27 .5 Good Formalin C-P Transverse 25 (Stain - Haematoxylin Eosin) aur., or. G. 48 .5 Male 1919
4205 E., 29.5 Good Bouin P Transverse 50 A1. coch. 55.5 Female 1923
4289 E., 32.2 Ch., 52x35x25 Good Formalin P Transverse 15, 20 A1. coch., Mallory 59 Female 1923
4525 E., 30 Good Formalin P Sagittal 20 (Stain - Haematoxylin Eosin) 57 Male 1924
4570 E, 30.7 Ch., 52X50X28 Exc. Bouin P Transverse. 15 (Stain - Haematoxylin Eosin) , phlox. 55 Male 1924
5154 E.,32 Good Bouin P Transverse 20 (Stain - Haematoxylin Eosin) 59.5 Male 1926
5422 E., 27 Good Formalin P Sagittal 40 (Stain - Haematoxylin Eosin) 52.5 Female 1927
5621A E., 27.5 Good Formalin P Transverse 20 (Stain - Haematoxylin Eosin) 52.5 Male 1927 Other twin has spina bifida and fused kidneys
5725 E, 23 Good Formalin P Coronal 25 (Stain - Haematoxylin Eosin) aur., or. G. 50.5 Female 1928
6573 E,31.5 Good Bouin C Transverse 20 (Stain - Haematoxylin Eosin) 58.5 Female 1932
7425 E, 27 Exc. Bouin C-P Coronal 20 (Stain - Haematoxylin Eosin) 47 Female 1937 Ag added
9226 E, 31 Exc. Formalin C—P Transverse 12 Azan ? Female 1954
D.122 E, 27 Exc. ? ? Transverse 19 Ag ? ? 1976 Yntema and Truex
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

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

Hinrichsen Collection

Stage 23 Human Embryo (ME45) 31 mm Face. Note the SEM ventral view of the embryo.

ME45 001.jpgME45 002.jpg

Domenech-Mateu Collection

Stage 23 Human Embryo (E109) 30 mm Abdomen, thorax

Domenech-Mateu Collection Embryo - E109 
Carnegie
Stage
Embryo Original CRL (mm) Section
thickness
Staining Section plane
23 E109 Bi-1 30 10 ?? Sagittal
Links: Carnegie Stage 23 | Domenech-Mateu Collection | DEC - Domenech-Mateu Collection


Events

  • Head Development[3]
    • superficial vascular plexus - has spread nearly to the vertex of the head.
  • limb[3]
    • length - considerable growth occurred in two days.
    • forearm - sometimes raised to a level above that of the shoulder
    • hands - extend far out in front of the embryo.
    • humerus - All five cartilaginous phases are now present[2] (Streeter, 1949, figs. 3 and 18).
  • vision
    • 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).[4]
    • 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[5], figs. 51 and 59).
    • Optic nerve a vascular canal is present and sheath in the more advanced specimens (O’Rahilly, 1966[5] , fig. 55).
  • smell
    • the olfactory strands are well individualized, and olfactory and terminal-vomeronasal fibers are easily distinguishable.[6] Stages Description
    • Vomeronasal organ - A narrow canal is seen in the long, tapering duct. The sac is beginning to shrink and retrogress.
  • hearing - Cochlear duct tip now points “downward” for the second time. The duct is coiled to nearly its final extent of 2½ turns.
  • joint - knee cavity, anterior cruciate ligament and posterior cruciate ligament present[7]
  • submandibular gland - Long duct, much branched. Lumen deep in gland. Lumina in many terminal branches of ducts. Beginning orientation of epithelial tree. Angiogenesis beginning around epithelium. Mesoblast begins to form layer around gland.[3] Lumina are found in many terminal branches of the duct. 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.
  • endocrine[8]
    • 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.
    • pineal - pineal body has reached Stadium 5 of Turkewitsch (1933).[9]
    • 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
      • 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.[10]
      • 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 chromaffin cells.[10]
  • meninges (spinal cord) - dura mater may be followed completely around the inner wall of vertebral canal. Ventral dura rudiment is a densely cellular band of tissue with most medial parts in direct contact with tissues associated with dorsal surfaces of centra and intervertebral disks. Stratified cells lying on dorsal surface of centra and intervertebral disks can be separated into three layers: an outer perichondrial layer adjacent to cartilaginous tissue; an intermediate layer more restricted in transverse extent and ultimately forms dorsal longitudinal ligament; and an inner layer the ventral dura rudiment.[11]
  • genital[12]
    • testis Testicular tubules are visible.[13] The rete testis makes contact but no actual union with the mesonephric elements[14]. The urogenital union occurs in the fetal period. Clusters of cells begin differentiation into the interstitial cells.[15]
    • ovary Rete ovarii closely related to, but not united with, mesonephric elements.[14]
    • uterus Paramesonepltric ducts meet the urogenital sinus and fuse together in the median plane. [16][17] The sinusal (Mullerian) tubercle has appeared>[16]
    • External genitalia developed not sufficently for sex detection.[18]
  • skeletal muscle[19] skeletal muscles of the trunk and limbs could be individually identified in their relative adult position. Pectoralis major muscle was divided in three separate muscle heads. Highly developed extraocular, infrahyoid and suprahyoid muscles. Absence of the facial muscles that have been described to be present at this stage of development.
  • palate - levator veli palatini muscle now runs along the auditory tube its full length.[20]
  • ventral body wall - rectus muscles reach the umbilicus.[21]

References

  1. Streeter GL. On the development of the membranous labyrinth and the acoustic and facial nerves in the human embryo. (1906) Amer. J Anat. 6:139-165.
  2. 2.0 2.1 Streeter GL. Developmental horizons in human embryos (fourth issue). A review of the histogenesis of cartilage and bone. (1949) Carnegie Instn. Wash. Publ. 583, Contrib. Embryol., 33: 149-169. PMID: 18144445
  3. 3.0 3.1 3.2 3.3 Streeter GL. Developmental Horizons In Human Embryos Description Or Age Groups XIX, XX, XXI, XXII, And XXIII, Being The Fifth Issue Of A Survey Of The Carnegie Collection. (1957) Carnegie Instn. Wash. Publ. 611, Contrib. Embryol., 36: 167-196.
  4. Pearson AA. (1980). The development of the eyelids. Part I. External features. J. Anat. , 130, 33-42. PMID: 7364662
  5. 5.0 5.1 O'Rahilly R. The early development of the eye in staged human embryos. (1966) Carnegie Instn. Wash. Publ. 625, Contrib. Embryol., 38: 1-42.
  6. Bossy J. Development of olfactory and related structures in staged human embryos. (1980) Anat. Embryol., 161(2);225-36 PMID 7469043
  7. Mérida-Velasco JA, Sánchez-Montesinos I, Espín-Ferra J, Mérida-Velasco JR, Rodríguez-Vázquez JF & Jiménez-Collado J. (1997). Development of the human knee joint ligaments. Anat. Rec. , 248, 259-68. PMID: 9185992
  8. O'Rahilly R. The timing and sequence of events in the development of the human endocrine system during the embryonic period proper. (1983) Anat. Embryol., 166: 439-451. PMID 6869855
  9. O'Rahilly R. The development of the epiphysis cerebri and the subcommissural complex in staged human embryos. (1968) Anat. Rec., 160: 488-489.
  10. 10.0 10.1 Crowder RE. The development of the adrenal gland in man, with special reference to origin and ultimate location of cell types and evidence in favor of the "cell migration" theory. (1957) Contrib. Embryol., Carnegie Inst. Wash. 36, 193-210.
  11. Sensenig EC. The early development of the meninges of the spinal cord in human embryos. (1951) Contrib. Embryol., Carnegie Inst. Wash. Publ. 611.
  12. O'Rahilly R. (1983). The timing and sequence of events in the development of the human reproductive system during the embryonic period proper. Anat. Embryol. , 166, 247-61. PMID: 6846859
  13. Gillman J. The development of the gonads in man, with a consideration of the role of fetal endocrines and the histogenesis of ovarian tumors. (1948) Contr Embryol Carneg Instn. 32: 81-131.
  14. 14.0 14.1 Wilson KM. Origin and development of the rete ovarii and the rete testis in the human embryo. (1926) Carnegie Instn. Wash. Publ. 362, Contrib. Embryol., Carnegie Inst. Wash., 17:69-88.
  15. Pelliniemi LJ. and Niemi M. Fine structure of the human foetal testis. I. The interstitial tissue. (1969) Z Zellforsch mikrosk Anat 99: 507-522.
  16. 16.0 16.1 Koff A. Development of the vagina in the human fetus. (1933) Contrib. Embryol., Carnegie Inst. Wash. Publ. 443, 24: 59-60.
  17. Pillet J. Reconstruction des organes pelviens d’embryons humains de 12,5 et de 25 mm CR. (1967) Ass Anat 51: 819-827.
  18. Wilson KM. Correlation of external genitalia and sex-glands in the human embryo. (1926) Carnegie Instn. Wash. Publ. 363, Contrib. Embryol., Carnegie Inst. Wash. 18: 23-30.
  19. Warmbrunn MV, de Bakker BS, Hagoort J, Alefs-de Bakker PB & Oostra RJ. (2018). Hitherto unknown detailed muscle anatomy in an 8-week-old embryo. J. Anat. , , . PMID: 29726018 DOI.
  20. Kishimoto H, Yamada S, Kanahashi T, Yoneyama A, Imai H, Matsuda T, Takeda T, Kawai K & Suzuki S. (2016). Three-dimensional imaging of palatal muscles in the human embryo and fetus: Development of levator veli palatini and clinical importance of the lesser palatine nerve. Dev. Dyn. , 245, 123-31. PMID: 26509917 DOI.
  21. Mekonen HK, Hikspoors JP, Mommen G, Köhler SE & Lamers WH. (2015). Development of the ventral body wall in the human embryo. J. Anat. , 227, 673-85. PMID: 26467243 DOI.

Additional Images

Historic Images

Historic Disclaimer - information about historic embryology pages 
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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 19) Embryology Carnegie stage 23. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_23

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