Description of the Early Developmental Stages of the Sense Organs of the Egyptian Passer Domesticus | ||
| Benha Journal of Applied Sciences | ||
| Article 37, Volume 5, Issue 7 part (1) - (2), October 2020, Pages 255-268 PDF (943.86 K) | ||
| Document Type: Original Research Papers | ||
| DOI: 10.21608/bjas.2020.300814 | ||
| Authors | ||
| S.I. Abdel Hady1; M.A. Emam2; SH.A. El-Sayed*1 | ||
| 1Zoology Dep., Faculty of Science, Benha Univ, Benha. Egypt. | ||
| 2Histlogy Dep. , Faculty of Veterinary Medicine, Benha Univ, Benha. Egypt. | ||
| Abstract | ||
| The present study deals with the development of the early embryonic stages of the sense organs andtheir surrounding mesenchyme of Passer domesticus at 8, 10, 15 and 19 mm total body lengths. The olfactory organs began its appearance in 15 mm stage as two olfactory placodes. They are formed ventro-laterally to most anterior part of the fore brain then they invaginated forming two olfactory pits. An olfactory sac and its lateral and medial nasal processes formed in19 mm stage. The two eyes arised as two optic vesicles in 8 mm stage simultinously with the lens placode opposing to them. The optic vesicle invaginated in 10 mm stage to form the optic cup simultaneously with the invagination of the lens placode forming the lens pit. In15 mm stages, a double layered optic cup with its choroid primordium are formed. Also, the primary fibers of the lens are formed and arranged in concentric layers with lens epithelium. In 19 mm stage, the optic cup gave two layers; inner neural and outer pigmented layers. Also, the corneal epithelium was formed. The first appearance of sclera primordium was in 19 mm stage. The membranous labyrinth of the inner ear began to appear at 8 mm stage as an otic placode from the ectodermal layer at the level of the hind brain. Then it invaginates to form the otocyst. The invagination process of the otocyst was completed in 10 mm stage. The ductus endolymphaticus appeared in the dorso-lateral portion of the middle part of otocyst in 15 mm stage, followed by the ductus cochleararis from the ventro-medial wall in 19 mm stage. The beginning of condensation process; the first step towards the otic capsule chondrogenesis was in 19 mm stage. By comparing the present results with other studied avian species revealed a similar genesis of the early development of the main three sense organs when compared to the other studied avian species. | ||
| Keywords | ||
| Passer; Embryo; Early Stages; Olfactory; Eye; Ear; Mesenchyme; Development | ||
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