by Dr. Gary Farr on 3 August 2003
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The skull or cranium forms a protective cover for the {brain} brain and the sense organs, and provides a basis for the face. It also represents the beginning of the {resp_system} respiratory and {digestive_system} digestive tract. With the exception of the mobile lower jaw, the skull bones in adults are fixed in place to form a whole. Race and constitution can affect the shape of the skull, and different individual forms exist. Different methods of measurement are used to distinguish these various forms, yet all describe the ratio of skull width to skull length.
A distinction is made between the neurocranium and the visceral cranium, which denote the brain and face parts of the skull respectively. The border between these two parts runs past the root of the nose, along the top edge of the eye sockets and across to the external auditory canals.
The neurocranium and visceral cranium are composed of individual bones which, with a few exceptions, are connected to each other by solid bone (known as a synostoses), by {joints} bone sutures, or by {joints} primary cartilaginous joints (synchondroses).
The neurocranium can be divided into the bony roof of the skull (calvaria) and the base of the skull (basis cranii), which denotes the inner surface of the skull floor consisting of three furrows.
The neurocranium comprises the occipital bone, the temporal bones, the sphenoid bone, the frontal bone, the parietal bone and the ethmoid bone. (see below).
The visceral cranium comprises the upper jaw (maxilla), the palatine bone, the zygomatic bone, the nasal bone, the lacrimal bone, the vomer, the inferior concha and the (independent) lower jaw bone (mandibula). The next several figures detail these bones.
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To view a detailed listing of the bones and cartilges of the head and neck, click {bones_head_neck} here.
For a detailed listing of the organs of the head and neck click {viscera_heaad_neck_alpha} here.
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