Anatomical and histological structure of the cornea in Sparrow hawk Accipiter nisus

Abstract

The current study conducted to investigate the anatomical and histological structure of the cornea in sparrow hawk accipiter nisus. By using an optical microscope and histological stains. Anatomical results showed that the cornea composed of two parts, the peripheral cornea and the central cornea, and there was variation in corneal thickness according to the anatomical region. Histologically, the cornea consists of five layers. The first layer of the central cornea consists of non- keratinized stratified squamous epithelial tissue composed of four rows of cells. Whereas, Bowman's membrane appeared clear and thicker on the dorsal side than on the ventral side. The corneal stroma consists of collagen fibers arranged in three secondary layers within the stroma. The corneal stroma also distinguished by the presence of fibroblast cells, which randomly distributed among the collagen fibers. The Descemet membrane appeared clear and equal in thickness between the dorsal and ventral sides. The endothelium tissue appears in the form simple squamous epithelia. The histological structure of the cornea root seemed similar to its formation in the central cornea. Still, it characterized by the presence of pigment cells spread in the stromal corneal root. Among the distinct results that appeared in this study is the presence of blood vessels spreading in the root of the cornea. The study concluded that the anatomical and histological structure of the cornea in this bird distinguished by some specialties that contribute to increasing the effectiveness of the function of the cornea in this bird.

Keywords

• cornea
• bowman's membrane
• descemet membrane
• sparrow hawk