EPicks: Cardiorespiratory adaptations in small cetaceans and marine mammals

In this EPicks videos, Andreas Fahlman of Global Diving Research SL, Valencia, Spain, talks about his research paper on 'Cardiorespiratory adaptations in small cetaceans and marine mammals'.
Find out more in Experimental Physiology:
'Cardiorespiratory adaptations in small cetaceans and marine mammals'.
Andreas Fahlman.
109 (3) pp. 324-334
physoc.onlinelibrary.wiley.co...
Transcript:
My name is Andreas Fahlman and I am a comparative physiologist whose study extreme physiology in breath-hold diving vertebrates. Using past studies, we developed the selective gas exchange hypothesis, which is a recently developed mechanism how breath-hold divers are able to selectively exchange O2 and CO2 with lung and blood while avoiding exchange of N2.
Cetaceans are able to do so by a lung architecture that allows regional alveolar collapse at shallow depths, and by hypoxic pulmonary vasodilatation that preferentially directs blood to collapsed regions. When this mechanism fails, as during stress, blood flow is directed to open regions of the lung which results in excessive uptake of N2 which increases the risk for the formation of gas emboli and symptoms of decompression sickness. An important part of the selective gas exchange hypothesis is the conditioned capacity to vary heart rate depending on the planned dive, or to changes in the dive plan. You can see this in this video, where the heart rate at the end of the dive begins to increase before this trained false killer whale reaches the surface to breath.
Comparative physiology allows us to understand how animals have solved physiological problems and for diving mammals such knowledge may help us find novel treatments to clinical problems such as alveolar collapse and cardiac arrythmias.