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Skull

The skull is a "brain bucket."  It holds and protects the brain, eyeballs, nose and ears.  The skull is made of the face bones and the protective helmet called the cranium.  The cranium is made of 8 flat bones that are connected by sutures.  The sutures are simply bumpy edges that fit together like puzzle pieces.  They are called sutures because they have the appearance of stitches (another word for sutures).  The face bones form the base for the soft tissues of the face.  There are holes in the face bones for the eye sockets and nose (i.e., the nasal cavity).  The mandible forms the lower jaw, which can drop downward to open the mouth.  The sinuses are air pockets within the skull.  The sinuses reduce the overall weight of the skull without a big decrease in the skull's strength.  The sinuses also help the voice reverberate, making it louder and clearer.  This is similar to the effect of an acoustic guitar.  When a child has sinusitis and the sinuses are filled with fluid, the voice becomes muffled.

Cranium bones

Ethmoid bone - A bone that is hidden within the nasal cavity.  It forms the nasal septum (the wall between the left and right nostrils) and the roof of the nose, called the cribriform plate.  The cribriform plate has many holes through which the olfactory nerves pass.  These nerves provide the sense of smell.

Frontal bone - The forehead bone.  Forms the upper part of the eye socket underneath the eyebrows.

Occipital bone - Forms the back of the cranium and provides the attachment point for the spine.  A large hole in the occipital bone, called the foramen magnum, provides an opening for the spinal cord.

Parietal bones (right and left) - Provide a roof and side walls for the cranium.

Temporal bones (right and left) - Form the lower sides of the cranium.  Beneath the temples and has holes on each side for the acoustic meatus (the ear opening). Provides an attachment point for the jawbone (mandible). 

Sphenoid bone - A butterfly-shaped bone that helps form the floor of the cranium and part of the eye socket walls.  Contains a small, saddle-shaped sunken area called the sella turcica which protects the pituitary gland.

Face bones

Lacrimal bones - Small plate-like bones that help form the inside walls of the eyesocket.  These bones contain a tube (called the nasolacrimal duct) through which tears from the eyes are drained into the nose.  

Mandible - The jaw bone.  This bone moves up and down as you open and close your mouth.  It holds your lower teeth and is the only bone of the skull that moves.

Maxilla - The bone that holds your upper teeth.

Nasal bone - The upper part (or bridge) of the nose.  This is the hard part of the upper nose.  The lower part of the nose and nostrils contains cartilage.

Palantine bones - Help form the floor of the nose, roof of the mouth and part of the nasal septum.  

Vomer bone - Deep within the nose, it helps form the nasal septum.

Zygomatic bones -  Helps form the cheek with the zygomatic arch and form the lateral sides of the eye socket.

Sinuses

The sinuses are air pockets within the skull.  The sinuses reduce the overall weight of the skull without a big decrease in the skull's strength.  The sinuses also help the voice reverberate, making it louder and clearer.  This is similar to the effect of an acoustic guitar.  When a child has sinusitis and the sinuses are filled with fluid, the voice becomes muffled.  See article on sinuses.

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Last Updated (Monday, 03 August 2009 18:45)