1. Our brain is very delicate and important organ.
2. It is that delicate ,that even by simple jerk,it can undergo wear and tear and may have a serious impact on our whole body.
3. Thus,nature has provided us with skull,which is a rigid cage of bone,in which brain is safely kept and is floating in a fluid ,which prevent the rupture of brain from the strong bone of skull.
4. Our skull joints are not like the joints in our hands and legs,which are movable. They are immovable,because if they move,due to their movement,our brain will suffer jerks and get damaged due to wear and tear.