... and Sp2, revealing a sub-atmospheric mean pressure at the Sp1 and an over-atmospheric mean pressure at the Sp2. In the mesothoracic air sacs, the mean pressure is sub-atmospheric, conditioned by the only slightly open spiracles. In a split flow-through chamber experiment, the CO 2 released through the Sp2...

... computerized tomographic (CT) scans of live penguins were utilized to measure lung volumes, air sac volumes, tracheobronchial volumes and total body volumes at different inflation pressures in three species with different dive capacities [Adélie ( Pygoscelis adeliae ), king ( Aptenodytes patagonicus...

...T. Knower Stockard; J. Heil; J. U. Meir; K. Sato; K. V. Ponganis; P. J. Ponganis SUMMARY In order to determine the rate and magnitude of respiratory O 2 depletion during dives of emperor penguins ( Aptenodytes forsteri ),air sac O 2 partial pressure ( P O 2 )was recorded in 73 dives of four birds...

...P. J. Ponganis; G. L. Kooyman; R. Van Dam; Y. LeMaho ABSTRACT To evaluate blood N 2 uptake and the role of the respiratory volume (air sacs/lungs) as a N 2 and O 2 reservoir in deep-diving penguins, diving respiratory volume ( V DR), heart rate ( f H), venous , blood volume ( V b ) and hemoglobin...

...Dona F. Boggs; Patrick J. Butler; Stacy E. Wallace ABSTRACT The air in the respiratory system of diving birds contains a large proportion of the body oxygen stores, but it must be in the lungs for gas exchange with blood to occur. To test the hypothesis that locomotion induces mixing of air sac air...