title: Minor contributions of the maxillary sinus to the air-conditioning performance in macaque monkeys.
abstract: The nasal passages mainly adjust the temperature and humidity of inhaled air to reach the alveolar condition required in the lungs. By contrast to most other non-human primates, macaque monkeys are distributed widely among tropical, temperate and subarctic regions, and thus some species need to condition the inhaled air in cool and dry ambient atmospheric areas. The internal nasal anatomy is believed to have undergone adaptive modifications to improve the air-conditioning performance. Furthermore, the maxillary sinus (MS), an accessory hollow communicating with the nasal cavity, is found in macaques, whereas it is absent in most other extant Old World monkeys, including savanna monkeys. In this study, we used computational fluid dynamics simulations to simulate the airflow and heat and water exchange over the mucosal surface in the nasal passage. Using the topology models of the nasal cavity with and without the MS, we demonstrated that the MS makes little contribution to the airflow pattern and the air-conditioning performance within the nasal cavity in macaques. Instead, the inhaled air is conditioned well in the anterior portion of the nasal cavity before reaching the MS in both macaques and savanna monkeys. These findings suggest that the evolutionary modifications and coetaneous variations in the nasal anatomy are rather independent of transitions and variations in the climate and atmospheric environment found in the habitats of macaques.
authors.affiliation: Interfaculty Initiative in Information Studies, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan Earthquake Research Institute, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan.
authors.forename: Futoshi
authors.initials: F
authors.lastname: Mori
authors.affiliation: Kanazawa Institute of Technology, Nonoichi, Ishikawa 921-8501, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Hanida
authors.affiliation: RIKEN Advanced Institute for Computational Science, Kobe, Hyogo 650-0047, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kumahata
authors.affiliation: Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Miyabe-Nishiwaki
authors.affiliation: Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan.
authors.forename: Juri
authors.initials: J
authors.lastname: Suzuki
authors.affiliation: Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292, Japan.
authors.forename: Teruo
authors.initials: T
authors.lastname: Matsuzawa
authors.affiliation: Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan nishimura.takeshi.2r@kyoto-u.ac.jp.
authors.forename: Takeshi D
authors.initials: TD
authors.lastname: Nishimura
mesh_terms: D000388:Air; D000818:Animals; D002522:Chlorocebus aethiops / Q000033:anatomy & histology / Q000502:physiology*; D003198:Computer Simulation; D005260:Female; D006813:Humidity; D057446:Hydrodynamics; D008251:Macaca / Q000033:anatomy & histology / Q000502:physiology*; D008297:Male; D008443:Maxillary Sinus / Q000033:anatomy & histology / Q000502:physiology*; D009296:Nasal Cavity / Q000033:anatomy & histology / Q000502:physiology*; D013696:Temperature
keywords: Computational fluid dynamics; Humidity; Nasal airflow; Nasal cavity; Primates; Temperature