Comparative Histological and morphometrical study of lacrimal apparatus of Awasi sheep and native black goat

Abstract

Abstract: The aim of the study was to explain general histological features of lacrimal apparatus of both animals. Eight pairs of Lacrimal glands, eight pairs of superior lacrimal glands of third eyelid and the same number of extra glandular duct system used for histological study. lacrimal glands were compound mixed tubuloacinar glands composed of serous, mucous and mixed acini (have both serous and mucous cells) . The percentage of acinar shape was greater than tubular shape of both glands of the studied animals, while the mucous acini were comparatively greater in lacrimal glands of Awasi sheep than those of black goat were. It was considerable increase in numbers of myoepithelial cells of secretory acini of lacrimal glands in black goat. The intercalated ducts were lined with low couboidal epithelium, then gradually increase in height to become stratified cuboidal to stratified columinar epithelium in both sheep and goat. It was noticed that the percentage of light cells and goblet cells within the wall of duct system inside the glands of Awasi sheep was greater than that of black goat, while the percentage of goblet cells in the wall of all parts of extra glandular duct system of the black goat was greater than that of Awasi sheep. There was a variable amount of smooth muscle fibers around the connective tissue of interlobular ducts especially in the superior lacrimal gland of third eyelid of black goat.