Energy efficiency of respiration in mature and newborn reindeer
Simon Birger Byremo Solberg , Signe Kjelstrup , Elisa Magnanelli , Natalya Kizilova , Iratxe Lorea Casado Barroso , Mario Acquarone , Lars P. Folkow
Reindeer (Rangifer tarandus) have evolved elaborate nasal turbinate structures that are perfused via a complex vascular network. These are subject to thermoregulatory control, shifting between heat conservation and dissipation, according to the animal’s needs. The three-dimensional design of the turbinate structures is essential in the sense that they determine the efficiency with which heat and water are transferred between the structure and the respired air. The turbinates have already a relatively large surface area at birth, but the structures have yet not reached the complexity of the mature animal. The aim of this study was to elucidate the structure–function relationship of the heat exchange process. We have used morphometric and physiological data from newborn reindeer calves to construct a thermodynamic model for respiratory heat and water exchange and present novel results for the simulated respiratory energy losses of calves in the cold. While the mature reindeer effectively conserves heat and water through nasal counter-current heat exchange, the nose of the calf has not yet attained a similar efficiency. We speculate that this is probably related to structure-size limitations and more favourable climate conditions during early life. The fully developed structure–function relationship may serve as inspiration for engineering design. Simulations of different extents of mucosal vascularization suggest that the abundance and pattern of perfusion of veins in the reindeer nasal mucosa may contribute to the control of temperature profiles, such that nasal cavity tissue is sufficiently warm, but not excessively so, keeping heat dissipation within limits.
|Journal series||Journal of Comparative Physiology B-Biochemical Systemic and Environmentalphysiology, [Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL PHYSIOLOGY], ISSN 0174-1578, e-ISSN 1432-136X|
|Publication size in sheets||0.55|
|ASJC Classification||; ; ; ;|
|Score||= 140.0, 25-06-2020, ArticleFromJournal|
|Publication indicators||= 0; : 2018 = 0.935; : 2018 = 2.341 (2) - 2018=2.259 (5)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.