The Skull is the most complicated bony structure of the body but every feature serves a purpose.
Internally, the main hollow chamber of the skull has three levels that support the brain, with every bump and hollow corresponding to the shape of the brain. Underneath and toward the back of the skull is a large round hole, the foramen magnum, through which the spinal cord passes. To the front of this are many smaller openings through which nerves, arteries, and veins pass to and from the
brain. The roof of the skull is formed from four thin, curved bones that are firmly fixed together from the age of about two years. At the front of the skull are the two orbits, which contain the eyeballs,
and a central hole for the airway of the nose. The jaw bone hinges on either side at ear level.
