Morphological Description and Histological Structure of Olfactory Organ in Barn Owl (Tyto alba)

Abstract

   The Morphological description and histological structure of olfactory organ in barn owl have been studied. The results of morphological description showed that the olfactory organ in the animal under study have pair of external nares ovale shape which lead to pair of nasal chambers which are located at the dorsal surface of head under eyes level. The chambers are conical in their shape the anterior end is narrow while the posterior end is enlarger the nasal chambers open to the oral cavity through the internal nares.      The results also showed that the nasal cavity contains three chonchae which represented by rosteral chonchae, elongated middle chonchae and the posterior nasal chonchae called olfactory or caudal which appear curled and represented smallest in size.      Microscopical examination results showed that the tissue surrounded the external nares is keratinized stratified squamous epithelium, which extends above the nares edges to the beginning of nasal cavity and forming the vestibular epithelium which appears as a column of the epithelial cells.      The respiratory epithelium is found in the respiratory region and covered the middle chonchae, and is represented by ciliated pseudostratified columnar epithelium, on the other the hand olfactory epithelium is found in the olfactory region and covered the caudal chonchae is represented by non-ciliated pseudostratified columnar epithelium. The study showed that vomeronsal organ is losted.