2.59 Transport systems in multi cellular animals

1. This issue with large organisms is that the surface area to volume ratio is very small.
2. This results in slow diffusion.
3. Let's take an elephant for an example. If there was no circulatory or ventillation system, then the oxygen molecules would have to diffuse up to a meter from the outside of the elephant to the cells which are in the center of the elephant,
4. Diffusion distances are big, resulting in slow diffusion.
5. The diffusion system is slow so respiration isn't possible. The oxygen would not get to the cells fast enough.
6. Elephants have developed transport systems such as the ventillation system and a circulatory system to deliver oxygen directly to the cells.
7. This gives it a short diffusion time.