COMPARATIVE ANATOMICAL , HISTOLOGICAL AND HISTOCHEMICAL STUDY OF (LARYNX, TRACHEA AND SYRINX) BETWEEN MATURE AND IMMATURE MALES OF LOCAL DUCK (Anas Platyrhnchos )

Abstract

The present study aims to compare gross anatomical, histological and histochemical structures of the larynx, trachea and syrinx between mature(Drake) and immature (Duckling) male duck(Anas platyrinchous). Twelve healthy local males ducks were divided into two groups. Six Drake at one year old and six Duckling at three months .For anatomical study the larynx, trachea and syrinx were measured by using vernia. For histological study specimens from larynx, trachea and syrinx were fixed in 10% formaldehyde after that the specimens embedded in paraffin. The next step tissues were sectioned using microtome and stained with routine stain and special stains .The anatomical results revealed that larynx, syrinx and trachea are identical in position in both Drake and Duckling , but differ in size. The histological results revealed that larynx of both Drake and Duckling lined by keratinized pseudostratified squamous epithelial tissue that appears thicker in Drake than Duckling. Trachea of Drake and Duckling lined with ciliated pseudostratifed columnar epithelial with mucous glands , supported by ossified cartilages in Drake and hyaline cartilage in Duckling. Syrinx of both Drake and Duckling lining by the ciliated pseudostratifed columnar epithelial with few goblet cells. Beneath it the lamina properia and sub mucosa that contained in loose connective tissue with blood vessels and amount of elastic and collagen fibers beneath it in Drake spongy bone trabeculae that contains bone lacuna fills with osteocytes , while in Duckling hyaline cartilage. The hyaline cartilage consists of lacuna which contains chondrocytes.