Category:Carnegie Stage 9

From Embryology

This Embryology category shows pages and media related to Carnegie stage 9 of embryonic development. In human development this stage occurs during week 3 (post-fertilisation) or gestational age GA week 5 (LMP).


There is also a specific Carnegie stage 9 resource page.



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Carnegie Collection - Stage 9 
Serial No. Pairs of somites Size (mm) Grade Fixative Embedding Medium Plane Thinness (µm) Stain Year Notes
1878 2-3 Embryo, 1.38
Ch., 12x10.5x7.5
Good Formol P Coronal 10 (Stain - Haematoxylin Eosin) 1917 Described by Ingalls (1920).[1]
5080 1 Embryo, 1.5
Ch., 14.5
Poor Formol P Transverse 10 Al. coch. 1926 Studied by Davis (1927).[2]
7650 2-3 Embryo, 2-3 Good Alc & Bouim C-P Transverse 6 (Stain - Haematoxylin Eosin) 1939 Said to be female[3]
Abbreviations
  • 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)
  •  ? - unknown or not determined.
References
  1. Ingalls, N.W. 1920. A human embryo at the beginning of segmentation, with special reference to the vascular system. Carnegie Instn. Wash. Publ. 274, Contrib. Embryol., 11, 61-90.
  2. Davis, C. L. 1927. Development of the human heart from its first appearance to the stage found in embryos of twenty paired somites. Carnegie Instn. Wash. Publ 380, Contrib. Embryol., 19, 245-284.
  3. PARK WW. (1957). The occurrence of sex chromatin in early human and macaque embryos. J. Anat. , 91, 369-73. PMID: 13448995


Embryo Examples

Based on O'Rahilly, R. and Müller (1987)[1] and listed in order of number of pairs of somites.

  • 1 somite - Carnegie No. 5080. Studied and illustrated by Davis (1927, figs. 2–5 and 39–42) and Severn (1971, figs. 1–4). First pair of somites not separate rostrally and contain no myocoeles (Arey, 1938). Chorion, 14.5 x 1.5 mm. Embryonic disc, 1.5 mm. Reconstructed by Müller and O'Rahilly (1983, fig. 2).
  • 1 somite - A specimen described briefly by Baginski and Borsuk (1967).
  • 1-2 somites - (or more?) somites, Carnegie No. 7650. Reconstructed by Müller and O'Rahilly (1983, fig. 5).
  • 2 somites - Da 1 (Dann). An important specimen (fig. 9-2) possessing 2 pairs of somites (Studnicka, 1929; Florian and Völker, 1929; Arey, 1938), although featured originally as having only one. Described and illustrated in detail by Ludwig (1928). Removed from uterus. Chorion, 12 mm. Embryo, 1.8 mm in a straight line, 2.4 mm by flexible scale. Sectioned transversely at 8 μm. Stained with alum cochineal. Neurenteric canal present. Sections are housed in the Anatomisches Institut, Basel. Photographs of sections are in Carnegie Collection under No. 5982. Presumed age, about 21 days. Dorsal and median projections published (ibid., figs. 1 and 2; Florian and Völker, 1929, fig. 14). Reconstructed by Müller and O’Rahilly (1983, fig. 3).
  • 2-3 somites - H3. Described by Wilson (1914), according to whom it “possessed probably two, possibly three, pairs of somites.” Chorion, 8.5 x 5.7 x 5 mm. Embryo, 1.43 mm. Sectioned obliquely (transversely) at 10 μm. Stained with hematoxylin. Fixation not adequate for reconstruction. The relatively longer primitive streak suggests that this embryo may be less advanced than No. 1878. Prechordal plate, or at least prechordal mesoderm, figured (Hill and Florian, 1931b). Presumed age, 18–21 days.
  • 2/3 somites - Carnegie No. 1878 (figs. 9-3 to 9-7). An important specimen possessing 2 somites on the right side and 3 on the left. Florian (1934b) had certain difficulties and considered the embryo to be too small. Curettage. Chorion, 12 X 10.5 X 7.5 mm. Embryonic disc, 1.38 mm in a straight line. Described in detail and illustrated by Ingalls (1920) who believed that “the earliest recognizable stage of dextrocardia” is present, “to which might have been added later a more or less complete situs inversus viscerum”; at any rate, Davis (1927), who studied and illustrated the heart, considered that “the cardiac area is distorted.” Angiogenesis in chorion described by Hertig (1935). Primitive streak and node, 0.13 mm, according to Ingalls, but about 0.22 mm in fig. 15 of Florian and Völker (1929) and more than 0.3 mm in plate 5, fig. 9, of Bartelmez and Evans (1926). Neurenteric canal not patent but pit present (Bartelmez and Evans, 1926). Median projection published (ibid., plate 5, fig. 9; Florian and Völker, 1929, fig. 15; Müller and O’Rahilly, 1983, fig. 1).
  • 3 somites - T439 (Toronto). Possesses 3 pairs of somites (Arey, 1938), although considered originally as having only 2. Described by Piersol (1937).[2] Embryo (along surface), 2.03 x 0.72 mm. Sectioned sagitally. Neurenteric canal closed but its remains are identifiable. Primordial germ cells near allantois. Embryonic disc rostral to somites, including cardiac area, is retarded. Said to contain no blood vessels in any part of the embryo itself.
  • 3 somites - Vant embryo. Described by Shaner (1945), who found “two to three pairs of somites.” Embryo (along curve), 1.5 mm. Thought to be 25 ± 2 days. Reconstructed again from original sections by Müller and O’Rahilly (1983, fig. 4).
  • 3 somites - Gv (Madrid). Described by Jiménez Collado and Ruano Gil (1963). Heart described by Orts Llorca, Jiménez Collado, and Ruano Gil (1960). Tubal. Embryo, 1.81 mm. Sectioned at 7 μm. Stained with hematoxylin and eosin. Reconstructed. On the basis of its external characters, said to lie between stage 9 and stage 10. Presumed age, 21 ± 1 days. Madrid Collection
  • 3 somites - No. 2008 (Prague). Excellent specimen (figs. 9-8 to 9-14) belonging to Dr. J. E. Jirásek. Embryo, 1.73 mm. Fixed in calcium formol. Sectioned transversely at 10 μm. Various stains used, including histochemical procedures. Should be published.
  • 3 somites - (?), His embryo E. This 2.1 mm specimen is listed by Bartelmez and Evans (1926) between No. 1878 (2–3 somitic pairs) and No. 3709 (4 somitic pairs, stage 10).

References


Piersol WH (1937) abstract 
Piersol, W. H. 1937. A human embryo of two somites, in situ. Anat. Rec, 67 suppl, 39-40. (American Association of Anatomists, Fifty-Third Annual Session, University of Toronto, Toronto, Canada, March 25 to 27, 1937)

(6) 88. A human embryo of two somites, in situ. W. H. Piersol, Department of Anatomy, University of Toronto.

The embryo measures 2.03 x 0.72 mm. and has been sectioned sagittally. Contact between embryonic and maternal tissue is preserved over a considerable area. although elsewhere there is separation due to shrinkage. Numerous glands form 9. broad stratum spongiosum. Flattened in the stratum compaetum, their middle parts are much dilated; toward the muscularis they are again flattened. Frequently they contain degenerated detritus and occasionally blood. A few glandular remains occur in the peripheral parts of the decidua capsularis. Chorionic villi are longest and most numerous toward the decidua marginalis. Their tips may reach the maternal tissues or a spongy mass of trophoblaet may intervene. Cytotrophoblast predominates, frequently bordered and penetrated by plasmodiotrophoblast. On the chorionic wall the trophoblast may show only one layer of nuclei but two layers are the rule. On the villi there are two layers of nuclei, the inner ones frequently belonging to distinct cells. The pericardial cavity is present but contains no heart, nor are their blood vessels in any part of the embryo, the chorion, or its villi. The neurenterie canal is closed but its remains are evident. An endodermal allantois projects into the connecting stalk. Small blood islands are present in the wall of the yolk sac and larger ones in the connecting stalk; the latter are forming endothelium.

Subcategories

This category has the following 4 subcategories, out of 4 total.

Media in category ‘Carnegie Stage 9’

The following 50 files are in this category, out of 50 total.