File:Rugh 056.jpg
Original file (943 × 800 pixels, file size: 90 KB, MIME type: image/jpeg)
Surface changes of the Frog's Egg at the time of Fertilization
(A) Sperm contact, entrance generally in the animal hemisphere.
(B) Second polar body emerges, the sperm penetrates the cortex, and the surface pigment recedes toward the sperm entrance point forming the gray crescent. Lateral view.
(C) Dorsal view showing the sperm penetration path, centrally located polar bodies and egg nucleus, and (arrows) pigment recession to form the gray crescent.
(D) Rotation of the sperm head and middle piece 180° as it veers from the penetration path to the copulation path, in line with the egg nucleus.
(E) First division spindle forming at right angles to the copulation path. Since the copulation and penetration paths are not in the same plane, the cleavage furrow does not cut through the middle of the gray crescent.
(F) When the penetration and copulation paths are continuous and in essentially a straight line, the first cleavage furrow will bisect the gray crescent.
Historic Disclaimer - information about historic embryology pages |
---|
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) |
Reference
Rugh R. Book - The Frog Its Reproduction and Development. (1951) The Blakiston Company.
Cite this page: Hill, M.A. (2024, May 13) Embryology Rugh 056.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Rugh_056.jpg
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 10:06, 12 April 2013 | 943 × 800 (90 KB) | Z8600021 (talk | contribs) | {{Rugh1951 footer}} |
You cannot overwrite this file.
File usage
The following 2 pages use this file: