File:Frazer1922 fig03.jpg

Fig 3. Pharynx during 8th week from below

To show how the forward growth progresses internal to the 2nd arch area and pouch, next the pharyngeal wall, and is evidently pushing forward from behind.

Plainly, it does not affect the outer part of the 2nd arch, and cannot displace the pouch towards the pharynx, and these characteristics remain. In fig. 3, they are as apparent in the 8th week, though by this time the alleged shifting inwards of the pouch ought to have been accomplished and done with long before. We can say, then, that on the one hand there is no growth capable of causing inward displacement of the pouch, and on the other the growth that is present is not only unable to bring about this movement, but, owing to its situation, could only move the pouch outwards—if it were near enough to affect it at all.

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Links: Fig 1 | Fig 2 | Fig 3 | Fig 4 | Fig 5 | Fig 6 | 1922 Frazer | Ernest Frazer | Historic Embryology Papers | Middle Ear Development

Reference

Frazer JE. The early formations of the middle ear and eustachian tube - a criticism. (1922) J Anat. 57(1): 18-30. PMID 17103958

Cite this page: Hill, M.A. (2024, April 27) Embryology Frazer1922 fig03.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Frazer1922_fig03.jpg

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