HOW DO WHALES BREATHE?
Whales are conscious breathers, which means they don't have a reflex or urge to breathe like us humans or other land-based mammals.
The function of breathing in these animals is under the voluntary control of the central nervous system (CNS). They don't continue breathing subconsciously whilst being busy with something else such as feeding or travelling, but will actually think about every breath they take - literally telling their body over and over again to take another breath.
In short, this means they choose to come to to the surface to breathe to supply their body with oxygen just like we decide to eat in order to not be hungry and starve.
Being aware and in control of the breathing avoids that a whale would accidentally take a breath underwater when running low on oxygen or still conducting a dive.
In addition to having full control over their breathing, whales also control the actions of their blowholes (which are equivalent to our nostrils, though of course, on top of their heads). Whenever on the surface, they open their blowholes which are otherwise held closed by strong muscles in order to avoid water coming into the lungs during a dive.
- Sarah
