What do lungs do?
In this video I do a quick crash course in what lungs do. To answer this we look at what problem lungs are trying to solve. Try to think about a human just absorbing oxygen through their skin, compared to say a worm, you should be able to see that we have a surface area to volume problem. As things get bigger, the volume increases faster than surface area and so we needed a way to increase our oxygen absorption surface area and reduce the diffusion distance of oxygen. This is what the lungs do! By having millions of tiny sacks called alveoli and inducing bulk flow in and out of these alveoli with the diaphragm, we massively increase our gas absorption surface area and massively decrease the diffusion distance of oxygen.
Learning objectives
Understand the basic anatomy of the lungs
Explain the surface area to volume problem
Define diffusion and explain the diffusion distance problem
Understand the role of the diaphragm in reducing diffusion distance through bulk flow
