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Document Type |
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Thesis |
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Document Title |
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Histological changes of pre and postnatal Skin Development in Rats التغيرات النسيجية لتكوين الجلد قبل وبعد الولادة في الجرذان |
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Subject |
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biological sciences department |
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Document Language |
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Arabic |
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Abstract |
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The skin is composed of the epidermis, dermis and hypodermis. Embryologically, the epidermis and its appendages are derived from the ectoderm. The mesoderm provides the mesenchymal elements of the dermis and subcutaneous fat. Aim of Work: The current study aiming to construct an organized source for light and transmission electron microscopic structure of (pre- postnatal) developing rat skin hoping to help future researches on skin during these ages. Material and Methods: The animals were sacrificed to take skin specimens from embryos and offsprings as follows: Group (A) Prenatal period (G) includes: day (12, 14, 16, 19, and 21). Group (B) Postnatal period (P) includes: day (1, 3, 7, 14 and 21). For LM study whole embryos and back skin were processed in paraffin as usual. The prepared sections were stained Hx&E and Masson Trichrome stain. Ultrathin sections were prepared for TEM study. Morphometric determination of the epidermal thickness was performed. Recorded data was statistically analyzed for evaluation of changes in the length, weight and epidermal thickness and tabulated. Results of current study Group A (prenatal) the epidermis in G12 appeared as a single layer of cells (periderm) while at G14 and G16 the epidermis had a double layer and desmosomes could be seen. At G19 the epidermis showed marked stratification with appearance of multiple cell layers and the epidermal cells revealed its superficial coating by peridermal cells. The keratohyalin granules and the dermo-epidermal junction with hemidesmosomes first revealed at G19. The germinal cell layer at G21 appeared as multiple rows (3-4 rows). Group B (Postnatal) from P1 to P21 the epidermis seems as adult skin with epidermis, dermis and muscle layer (panniculus carnosus). By Masson trichrome stain, there was no discrimination between superficial and deep dermis till G14 and collagen fibers evenly distributed at G16. At G19, there was discrimination between fine collagen fibers of the superficial dermis compared with condensed fibers deep in the reticular dermis. The dermis appeared rich in the green collagenous fibrous network in between the highly cellular dermis at G21 while in Group B There was condensation of the collagenous fibers in the dermis compared to the hypodermis at P (7-14). Bundles of collagen fibers appeared running in different directions inbetween dermal cells at P (21) The interstitial cells with junctional contact with dermal cells were detected by TEM till till age of P21. The multiple stages of hair follicle development could be observed as (early anagen) phase at P1, (mid-anagen) phase at P7, (late anagen) phase at P14. The typical hair follicular layer could be demonstrated at P21. Morphometrically, the epidermal cell thickness was increased directly with the age in the prenatal period (Group A) reaching the maximum by age of day 1 (P1). While, there was a progressive decrease in epidermal thickness in Group B from P3 up to P21. |
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Supervisor |
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Prof. Dr. Saleh A. Al-Kerayem |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1433 AH
2012 AD |
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Co-Supervisor |
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Dr. Seham K. Abu-nasef |
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Added Date |
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Sunday, July 15, 2012 |
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Researchers
| أشواق خالد الجابري | Al-Jabri, Ashwaq Khalid | Researcher | Master | |
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