Temperature profile of the nasal cavity in Japanese macaques.

The nasal cavity conditions respiratory air. The distribution of temperature within the nasal cavity has been examined in humans using various direct measurements. Macaques are a nonhuman primate species that are used as a model for understanding human physiology. They are widely distributed geographically in varied climate environments and they are expected to exhibit evolutionary anatomical and physiological adaptations in the air-conditioning. To provide basic data for developing an animal model in air-conditioning, we measured the distribution of temperature within the nasal cavity in Japanese macaques, Macaca fuscata. Inhaled air was well conditioned in the vestibular cavity and was almost fully conditioned before reaching the nasopharynx. This conditioning performance is better than that in humans. The anatomical and histological features of the nasal cavity are expected to explain this difference in physiological performance between the two species. These data will be helpful in establishing an animal model to understand and model airway air-conditioning performance in macaques and humans.