-
Asked by ace12 to Claire, Kate, Matt, Rob, Sam on 24 Jun 2013.
-
Sam Geen answered on 24 Jun 2013:
When we breathe, our lungs take in air, which go to the alveoli, which are little bags that look like bunches of grapes and have blood vessels flowing around them. They expand and contract to let in air, and don’t work well when they’re full of water – expanding and contracting is harder. The concentration of oxygen dissolved in water is also lower than in air.
-
-
Claire Lee answered on 24 Jun 2013:
Fish have gills, which are organs that are specifically designed to extract oxygen from the water. As Sam says, our lungs are designed to work in air, so they are not as efficient at extracting oxygen from water, so we don’t get enough oxygen to survive.
There is a (very experimental) technique being studied now called “liquid breathing” where you breathe in an oxygen-rich liquid rather than air. But this is still under study and I don’t know if anyone has actually done it yet
-
Matthew Pankhurst answered on 25 Jun 2013:
We need our lungs to be a little wet (on the inside of those little bags), so that oxygen can be captured from the air and transferred into our blood. But, too wet and the air can’t get close enough to the surface of our lungs. If we were to go underwater, we would basically choke on the water, and also our lungs would fill up with water and make us sink. 🙁 But! It’s not all bad – you can survive this with help from other people. I used to be a surf life saver in Australia, and we were trained to pull people out of the water, drain any water in them and breathe for them (pushing air into their lungs). I never was in the situation that I had to do this thankfully – but heaps of peoples lives have been saved by doing this.
Comments