The anatomy and histology of vomeronasal organ (VNO) of male Iranian helical horn goat (Capra Persica)

Vomeronasal organ is tubular structure which lies in floor of nasal cavity. The animals not only have essential olfactory system but also have accessory olfactory system. The vomeronasal organ has principle role in accessory olfactory system. This organ have principle role in urinary pheremones (sexual odor) sensation. In this survey, location, anatomical and histological structures of vomeronasal organ (VNO) of male Iranian helical horn goat (Capra Persica) were studied. 17 normal head of male Iranian helical horn goat were provided from Urmia industrial slaughterhouse. Twelve and five samples were used for anatomical and histological studies, respectively. The mandible of 12 samples were separated, and then the heads were sectioned longitudinally and horizontally (6 sections). Longitudinal sections are used for detection of length and horizontal sections are used for detection of diameter of VNO by biometry method. For histological studies, 4 sections were provided by maxilla in following regions: 4th palatine ridge, 8th palatine ridge, rostral of 1th premolar tooth, and midline of first premolar tooth. Sections are decalcified and then they were stained by H & E method. Vomeronasal organ of Iranian helical horn goat was observed on maxillary bone, dorsally and superiorly of incisive duct. Its average length was 7.8 cm. It extended from incisive papillae to second premolar tooth. Its maximum diameter was observed in middle region with 1.8 mm length. Histological studies showed that Jacobson organ is encapsculated by hyaline cartilage capsule. Olfactory epithelium is lined inner part and respiratory epithelium is lined peripheral part of Jacobson organ of male Iranian helical horn goat. Lamina propria and tunica submucosa were filled by vascular loose connective tissue with erectile tissue. Results of this research appeared that Jacobson organ of male Iranian helical goat is connected with oral cavity by incisive duct. This connection was reported in other animals. In this animal, Jacobson organ has extended from incisive papillae to 2nd premolar tooth. Results of this research is similar to other reports. Due to length of muzzle of male Iranian helical horn goat is shorter than other animals (horse, cattle, and buffalo) its Jacobson organ was shorter than them. Since mucus layer of Jacobson organ is lined by respiratory and olfactory epithelium particularly, therefore this organ plays an effective role for receiving sexual odor and has a physiological role in sexual behaviors.