Bending over and touching your toes describes flexion in reference to your intervertebral discs.
The mudflows are very dangerous and they have a great destructive power. They appear after a heavy rainfall on places that are steep. The mudflows are very fast and sudden occurrences, so usually people are caught unprepared. A mudflow is a mixture of water and lot of ground/mud, and all sorts of debris, which also contributes to it to be more dangerous.
Cells are limited in size because the outside also known as the plasma membrane must transport food and oxygen to the inside of the cell. This can be represented by what is known as the surface to volume ratio.
