I'm gonna go with the brain on this one.
The skull protects the brain.
It is not an organ system. Bones are not organs. It does help protect some organs, like the brain being inside the skull, but it is not part of an organ system.
The brain is on the inside the skull.
If you are a human, then your brain is inside your cranium, or skull.
the skull protects your brain.
if u mean internal organs in the skull, its the brain
The skull protects and supports the brain/brain membranes, and the sense organs.
the brain
There is no organ that shares it protection between the skull and ribcage. The skull protects the brain mainly and hte ribcage protects the heart and lungs.
skull, ribs, and bones
Your Head.
skull protects the brain,eyes part of the spinal cord and the eardrums