breath_and_diving

Breathing and diving:

Investigations has shown that every dolphins profile is very diffrent from the others when its about diving and how long to swim under water. Rough toothed whales and baird are amazing deepseadivers they can go down to 3000 meters deep and stay there for 2 hours.
bottlenose Dolphin live close to the surfice and can't be under water longer then 15 miniutes.

There "blowhole" is on the crown of there head and because of that they don't need to stay long at the surface to breath. There lungs are not really big but they breath much more effectively than animals on ground. When they breath there heart beats faster and that means much more blood can be circulated round the lungs and makes circualtion of oxygen faster.
There muscles can also collect air.

When they dive they hold there breath. there hearts start to beat slower. There blood is shared to the organs that need it most to finish the diving like the brain and heart. There digestive system closes down completly. The "tandvalar" can hold there breath for up to 2 hours they have adapted to a life life under the surfice.