The proximal airway of the bat Tadarida brasiliensis: a minimum entropy production design.
The bronchial tree of most mammalian lungs is a good example of an efficient distribution system whose geometry and dimensions of branched structures are important factors in determining the efficiency of respiration. Small and flying endothermic animals have high-energy requirements, requiring morphological and physiological adaptations to reduce energy loss. Here we show that Tadarida brasiliensis, a nocturnal small bat whose energy requirements are exacerbated by this small size and by their frequent exposure to high altitude, has a different morphology in the proximal airway, sustained by a wider trachea and better scaling factors, than other non-flying mammals. This design allows a great decrease of the volume specific resistance of the proximal airway and in consequence a very low entropy production during breathing, approximately 1/18 of that expected for a non-flying mammals of similar body size.
Canals
Mauricio
M
Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Casilla, 653, Santiago, Chile. mcanals@uchile.cl
Sabat
Pablo
P
Veloso
Claudio
C
D000531:Altitude; D000818:Animals; D003411:Arvicolinae; D049628:Body Size / Q000502:physiology; D001980:Bronchi / Q000033:anatomy & histology* / Q000502:physiology*; D002685:Chiroptera / Q000033:anatomy & histology* / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D019277:Entropy; D008954:Models, Biological; D011817:Rabbits; D051381:Rats; D012119:Respiration