Wikipedia has a good article on Free-Diving here, and the part of it that really impressed me, was the physiological elements of it:
Physiology of freediving
The human body has several adaptations under diving conditions, which stem from the mammalian diving reflex. These adaptations enable the human body to endure depth and lack of oxygen far beyond what would be possible without the reflex.
The adaptations made by the human body while underwater and at high pressure include:
- Reflex bradycardia: Drop in heart pulse rate.
- Vasoconstriction: Blood vessels shrink. Blood stream directed away from limbs for the benefit of heart, lungs and brain.
- Splenic contraction: Releasing red blood cells carrying oxygen.
- Blood shift: Blood plasma fills up blood vessels in the lung and reduces residual volume. Without this adaptation, the human lung would shrink and wrap into its walls, causing permanent damage, at depths greater than 30 meters.
While that was all amazing, I watched this presentation at TED last night, and while it contained amazing elements, it also contained some disturbing elements as well.
This is Brian Skerry, a photojournalist on the ocean's glory -- and horror.
That was awesome, thanks Koda. I felt like I was back at Uni but better, as I was in the comfort of my own home :)
ReplyDeleteSome people have a lot of moxy! I get scared in deep water.
I just love that there are people out there who have the skills to explore such a vast and unknown environment and then present it to us land dwellers. How hopeful to hear the presenter say that he does not believe it is too late and that we can protect the oceans. On that thought, a friend of mine recently said that she does not believe that the planet will 'die' but that the human race will kill itself off and the earth will regenerate and be just fine without us.
Good on New Zealand for being so progressive as spoken about in the second clip.
Thanks Koda, great food for thought.
Thanks Maureen!
ReplyDeleteThose TED video's are amazing... I put another one up today about the propensity of us humans to look for patterns. I think it applies a lot to religion and ritual.
And New Zealand is awesome. I went snorkeling a bunch when I lived there, and the sea life was pretty incredible. Once I saw a 2 meter long Conger Eel, which was cool and all, until I realized what it was... Scared the living hell out of me at that point!!!