the skull
•Made up of 22 bones: 8 cranial bones and 14 facial bones; there are also 3 bones in each middle ear
• Except for lower jaw, skull bones are connected by immovable joints called sutures
Bones of the cranium:
• Encloses and protects the brain, provides attachments for muscles, and contains air-filled paranasal sinuses that reduce its weight and increase vocal resonance.
• Frontal bone forms anterior part of skull, above eyes; features include the supraorbital foramen and the frontal sinuses
• Parietal bones form the roof and sides of the skull, just behind the frontal bone; they join along the midline at the sagittal suture, and meet the frontal bone along the coronal suture
The Cranium
The occipital bone forms the back of the skull and the base of the cranium; features include foramen magnum, and occipital condyles; joins parietal bones at lambdoid suture
The temporal bones form parts of the sides and base of the cranium; features include the external acoustic meatus, mandibular fossae, mastoid process, styloid process, and zygomatic process; connects to parietal bones at squamous suture
The sphenoid bone helps form the base of the cranium, sides of the skull and portions of the orbits; features include the sella turcica and sphenoidal sinuses
The ethmoid bone is located in front of the sphenoid bone; features include the cribriform plates, crista galli, a perpendicular plate, superior and middle nasal conchae, and ethmoidal sinus
Facial Skeleton
hold 13 immovable bones and a movable lower jawbone
These bones form the basic shape of the face, and provide attachments for muscles that move the jaw and control facial expressions
Bones of the Facial Skeleton:
• The maxillae form the upper jaw, hard palate, floor of the eye orbits, sides of the nasal cavity, house the upper teeth
• Palatine bones are L-shaped bones located behind the maxillae, that form the floor & lateral walls of the nasal cavity and the posterior portion of the hard palate
• Zygomatic bones form the cheekbones and lateral walls of the orbits
• Lacrimal bones form part of the medial walls of the orbits
• Nasal bones form the bridge of the nose
• Vomer bone makes up a portion of the nasal septum
• Inferior nasal conchae are fragile, scroll-shaped bones that support mucous membranes in the nasal cavity
• Mandible, or lower jawbone, supports the lower teeth