Histological Investigation on the Structural Aspects of Adult Brown Bears' Skin

Authors: Nesrin ÖZFİLİZ, Aytekin ÖZER

Abstract: This study was made to investigate the structures of te skin of Brown Bears which were brought to the Wildlife Research Centre (WRC) in Bursa. The skin samples were taken from 9 European Brown Bears. They were anesthetized and skin samples were removed from neck, shoulder, back, ventral of abdomen and rump with simple biopsi device. Cryostat sections were made at 10-15 mikron, were stained with oil-red o stain method (13) for lipids. Paraffin blocks are prepared for histological techniques. Sections were made at 5-7 mikron and were stained with Crossmann's triple stain (14), Bielchowsky's and Gomori's silver stain (15-16), Pinkus'(17) Orcein-giemsa method for morphological features. When the skin biopsies of different parts of the body were investigated, it was observed that the skin was composed of two basic layers, epidermis and dermis. Especially on the border of epidermis and dermis of the neck area, a network of retikular fibers was observed. Dermis was made of a dense network of collagen fibers and sparsely and irregularly established elastic and reticular fibers were observed among them. Around the hair follicles, sweat glands, sebaceous glands, vessels and bundles of nerve fibers, dense elastic and reticular fibers were observed. It was seen that the sebaceous glands were made of only a few cells. In the stratum reticulare of the dermis and around the hair follicles a mass of lipid cells were observed. In these areas it was seen that there were lots of nerve fibers surrounding the lipid cells. The total thickness of the skin was the thinnest on the ventral part of the abdomen and thickest on the back area.

Keywords: Bear, skin, structural aspects