Category:Carnegie Embryo 453

From Embryology

This Embryology category includes pages and images that relate to the Carnegie Collection Embryo No. 453.

References

Kunitomo K. The development and reduction of the tail and of the caudal end of the spinal cord (1920) Contrib. Embryol., Carnegie Inst. Wash. Publ. 272, 9: 163-198.


Embryo No. 453, 23 mm Crown-Rump Length

Kunitomo K. The development and reduction of the tail and of the caudal end of the spinal cord (1920) Contrib. Embryol., Carnegie Inst. Wash. Publ. 272, 9: 163-198.

In embryo No. 453 there are 35 vertebrae, the last consisting of precartilage tissue whicli has not as yet developed into true cartilage. The chorda dorsalis is straight and runs through the vertebral column in the midline. Its caudal end, however, .shows 4 coils, as shown in figure 40, representing a profile reconstruction of the specimen. The neural canal narrows at the thirty-first vertebra. At the level of the thirty-third vertebra a sac-shaped cell-mass lies between the spinal cord and the vertebral column, separated, however, frt)m the wall of the former (fig. 40, diverticulum). This sac seems to have resulted from a diverticulum of the ventral wall of the neural canal, the stalk of which has been obliterated. The ventral wall of the atrophic portion of the spinal cord shows small folds at the level of the thirty-fourth and thirty-fifth vertebrae. The caudal end of the spinal cord expands slightly and its extreme end enters into the tail, which is now quite reduced. The middle sacral artery communicates with the anterior spinal artery by means of a branch that curves about the tip of the vertebral column. The subcaudal epidermal plate has nearly disappeared, while the post-anal swelling and the coccygeal tubercle have become visible. There is a shallow furrow between the tail-end and the primordium of the coccygeal tubercle, constituting a boundary between them. This embryo has 32 spinal ganglia with nerves.


Cite this page: Hill, M.A. (2019, May 25) Embryology Carnegie Embryo 453. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Category:Carnegie_Embryo_453

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Pages in category ‘Carnegie Embryo 453’

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