How the skull protects the brain
The skull has evolved features that protect the brain in several ways.
The thick bone of the forehead, part of the frontal bone, protects the large masses of brain called the frontal lobes. But to keep the head light, much of the skull is more delicate. For instance, the temporal bone around the temple is quite thin.
The skull's nearly-spherical shape efficiently protects the delicate brain against pressure and impact. Since the brain has about the same consistency as jelly, it needs a lot of protection.
A nutrient mixture, the cerebrospinal fluid or CSF, bathes the brain and cushions it against collisions with the inside of the skull. A three-layered membrane system called the meninges fits between the CSF and the skull.
Despite this padding, some accidents can cause the brain to shift rapidly and bounce off the inside of the skull with enough force to do damage. A sudden impact can also damage the brain’s tissues or connections between brain cells or cause the blood vessels that feed the brain to rupture. The surface of the head can also be cut or bruised, especially if it hits a sharp object. In certain types of injuries, the skull may be fractured