ABSTRACT
To detect the origin and mode of development of spontaneous or induced tumors of the nasal cavities, their exact localization must be specified. Anatomical description of the nasal and paranasal cavities of healthy, untreated rodents are therefore necessary and will allow investigations to search for relationships between the anatomical characteristics of the tissues of origin and the mode of tumor differentiation. The nasal cavity of mice, rats, and hamsters are very similar and the following shows some important anatomical landmarks. The nasal cavity of the rodents used most frequently as laboratory animals is divided by atrioturbinalia, conehae nasales, and ethmoturbinalia. The atrioturbinals are structures of the nasal vestibule which possess a cartilaginous support. Conehae nasales are named according to the bones from which they originate. Therefore, the rodents have incisivo- and nasoturbinals. Two groups of ethmoturbinals are differentiated, ectoturbinalia and endoturbinalia. All of the ethmoturbinals are recorded consecutively from dorsal to oral.
