Abstract

        Histology, histochemistry and ultrastructure of dermis of skin in deer, goat and sheep was studied using the skin samples collected from spotted deer brought for post mortem at the College of Veterinary & Animal Sciences, Mannuthy, Thrissur zoo and Forest department; and from goat and sheep freshly slaughtered in Meat Technology Unit, Mannuthy. Samples of 1cm3 were collected for histological and histochemical studies from 27 regions of skin. Specimens for histological techniques were fixed in 10 per cent neutral buffered formalin. Serial sections of 5μm thickness were made. Histochemical staining was done with Alcian blue for carbohydrates, Oil Red ‘O’ in propylene glycol for lipids and Gomori’s method for acid and alkaline phosphatases. Samples of 1 mm3 size fixed in 2.5 per cent gluteraldehyde were processed for scanning electron microscopy. Histologically, the skin consisted of two layers, viz. a superficial epidermis and the deeper dermis, joined to the underlying structures such as muscle and cartilage by the subcutaneous tissue. Dermis had two layers: a superficial, thin papillary layer and a deep, thicker reticular layer. Papillary layer conformed to the contour of the stratum basalis of epidermis. Even though a clear demarcation was absent between papillary and reticular layers of dermis, both could be distinguished by the difference in nature and arrangement of connective tissue fibres, with the reticular layer consisting of large, coarse and loosely interwoven bundles of collagen fibres. Demarcation between dermis and subcutaneous tissue was obscure ventrally, but clear in dorsal regions. Sweat and sebaceous glands, as well as hair follicles were epidermal structures located in the dermis and subcutis. Blood vessels, lymph vessels and nerves traversed the dermis. Connective tissue components of the dermis provide strength and flexibility to the skin; cushion the body from stress and strain; its blood vessels account for nourishment and waste removal of both dermal and epidermal cells and nerve endings provide the sense of heat and cold making the dermis an important component of the largest sense organ of the body.

Keywords : Deer, dermis, goat, histology, histochemistry, sheep, ultrastructure