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Axial Skeleton. The Skull. The Skull. Two parts of the skull: The cranium encloses and protects the brain The facial bones hold the eyes and face shape. The Skull - Cranium. Eight large flat bones fused together ( sutures ): Frontal – forms forehead
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Axial Skeleton TheSkull
TheSkull • Two parts of the skull: • The cranium encloses and protects the brain • The facialbones hold the eyes and face shape
TheSkull - Cranium • Eight large flat bones fused together (sutures): • Frontal – forms forehead • Parietal – superior and lateral walls (paired) • Temporal – inferior to parietal, at temples (paired) • Occipital – posterior wall • Sphenoid – deep to the anterior of skull, forms floor of cranial cavity • Ethmoid – forms roof of nasal cavity, medial walls of orbits
The Skull - Face • Thirteen bones fused together, with one connected by joints • Maxillae – forms upper jaw (paired) • Palatine – posterior to maxillae, between back molars (paired) • Zygomatic – cheekbones, lateral walls of orbits (paired) • Lacrimal – part of medial walls of orbits, between ethmoid bones and maxillae (paired)
The Skull - Face • Continued… • Nasal – bridge of nose (paired) • Vomer – median line of nasal cavity • Inferiorconchae – bone projections from lateral wall of nasal cavity (paired) • Mandible – lower jaw, connected by only freely movable joint of face
The Skull • Hyoid Bone • Not technically part of skull • Does not articulate directly with any other bone • Anchored to temporal bones by ligaments • Movable base for tongue • Attachment point for neck muscles
The Skull – Bone Markings • Bone Markings • Meatus – canal-like passageway • External Auditory Meatus – canal leads to eardrum and middle ear (temporal) • Process – bony prominence • Styloid Process – inferior to auditory meatus (temporal) • Zygomatic Process – anterior to cheek bone (temporal) • Mastoid Process – posterior and inferior to auditory meatus (temporal) • Palatine Processes – extensions of maxillae that form the anterior part of the mouth (maxillae)
The Skull – Bone Markings • Foramen – opening through bone • Jugular Magnum – at junction of occipital & temporal bones, opening for jugular vein (temporal) • Carotid Canal – anterior to jugular foramen, opening for carotid artery (temporal) • Foramen Magnum – opening for spinal cord to connect to brain (occipital) • Foramen Ovale – opening for nerve fibers to pass to jaw muscles (sphenoid) • Condyle – rounded articular projections (involved with joints) • Occipital Condyles – rest on the first vertebra of the spinal column (occipital) • Sinuses – cavities in bone filled with air • Paranasal Sinuses – found in different bones surrounding nasal cavity (frontal, ethmoid, sphenoid, maxillae)