Comparative Morphological and Morphometrical study of Lacrimal apparatus of Awasi sheep and Black goat

Abstract

This study was included Morphological and Morphometrical measurements of Lacrimal glands ,determined course of the external ducts system &made measurements for all the parts of this system. Twelve of healthy heads of ram awasi sheep and the same numbers of buck black goats was used for this study. Lacrimal glands included paired of dorsal Lacrimal glands , paired of proximal Lacrimal glands of third eyelids absent of distal Lacrimal glands of third eyelid( harderian glands) , while , the external ducts system consist of dorsal & ventral Lacrimal punctae , dorsal & ventral Lacrimal canacliculi ,Lacrimal sacs ,nasaolacrimal ducts and nasal opening for the both sides of the studied animals. Dorsal Lacrimal glands are flatten oval in shaped , undifferentiated in lobulation ,situated at dorsul-lateral surface of the right &left eye in both animals, while the proximal glands of the third eyelids have pyriform in shaped of awasi sheep , oval elongated in black goat situated in the beginning of occular surface of the third eyelids situated like small aggregation at the both sides of the cartilage of the third eyelids .The width of both glands of awasi sheep was greater with that of black goat in the both sides The external duct system beginning from dorsal & ventral Lacrimal punctae that located near medial canthus of the eye ,these punctae drain by paired of canacliculi that was equal in length in the same animals ,the canacliculi separated by small bony material originated from internal surface of Lacrimal bone specially in black goat. These canacliculi of both animals daring into Lacrimal sacs that resemble the funnel in awasi sheep. The Lacrimal sacs in both animals lead to nasolacrimal ducts ,there was significant increase in the total length of the external duct system ,the external duct system in both sides of awasi sheep was longer than that of black goat .Finally the nasolacrimal ducts of both animals end at nasal opening that was very obvious specially in awasi sheep & the right nasal opening in awasi sheep was bigger in diameter than the same opening in black goat.