Anatomical and histological investigate of vomeronasal organ (VNO) in Iraqi sheep Alawasi

Th. A. Abass, Masarat S. Al-Mayahi, Bahaa F. Al-Hussany


    This work was focused on the vomeronasal organ (VNO) anatomically and histologically in Iraqi sheep. Vomeronasal organ (VNO) plays essential role in the urinary sensation pheromones (sexual scent) which has not been studied extensively. In this study, six samples of the VNO for both sexes, adult were taken from the normal heads of Iraqi sheep Alawasi. The VNO was located in the anterior portion, just in the floor of the nasal septum (ventrolaterally), it is a tubular crescent shape, 6 cmin length and opens cranially in the incisive duct and blinded end caudally at the level of 2nd upper premolar tooth. Histological examination of the VNO was revealed three regions were divided into cranial, middle and caudal. It is encompassed inside a cartilaginous capsule which appeared as U- shape in the cranial region, while in the middle region was a free ends of the U-shape beside separation the narrow cleft dorsally, in the caudal region the cartilage became circular (ring shape) and surrounding the VNO completely, which separated the organ from the respiratory epithelium of nasal cavity. The lumen of VNO appeared in cranial and middle region as a comma shape, while, the caudal region was heart in shape, the border was irregular due to the folding of epithelial mucosa. The lumen of VNO was lined by a sensory medial wall showing the bipolar sensory neuron supporting and basal cells and non-sensory epithelium in the lateral wall was contained the basal cells, ciliated columnar and goblet cells.

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