Chapter 12 Cranium Part 1

Cranial Bones Skull = ___________________ _______________ (8 bones) – Area that surrounds and protects the brain. –_______________________ –Floor

Calvaria _____________ ___________ (Right and Left) ____________

Frontal Bone _______________ (Vertical) Portion –Forehead _______________(Horizontal) Portion –Superior Orbits

Frontal Bone Squamous ________________ –Area between eyebrows ________________ –Depression above eyebrows _________________ –Superior rim of orbit __________________ –Ridge beneath eyebrow

Frontal Bone Orbital __________________ –Superior portion of each orbit _________________ –Separates orbital plate Articulates with 4 _____________ –Right and left parietals, sphenoid, ethmoid

Parietal Bones Forms the ________________calvaria. Articulates with 5 ________________ –Frontal, occipital, temporal, sphenoid, parietal

Occipital Bone _______________ portion of the calvaria. Squamous Portion _______________________________ –Prominent bump on the back of head.

Occipital _________________ –Hole for spinal cord ____________________- –Articulating surface on each side of foramen magnum. Articulates with 6 bones –2 parietals, 2 temporals, sphenoid, atlas

Cranial Floor _______________ (Right and Left) _______________

Temporal Bone Lateral aspect of skull. 3 Portions –_____________

Temporal Squamous Portion Vertical aspect and very thin. _______________________ –Articulates with Zygoma –TMJ

Temporal Mastoid Portion Posterior to ____________ ___________________ Mastoid Tip

Temporal Petrous Portion ____________________________ ___________________ –Petrous Ridges ______________________ –Opening for the nerves of hearing and equilibrium ____________Process

Sphenoid Centrally located. ______________cranial bones. ____________________ –Houses __________________ –__________– Posterior wall of sella –_____ – Depression posterior to dorsum sella. –Posterior clinoid –Anterior clinoid

Sphenoid _________________ –Anterior clinoid ________________ –Forms portion of floor and walls of cranium

Sphenoid ___________________ –Lateral downward projections ____________________ –Medial downward projections ___________________ –Process off of medial pterygoid

Sphenoid Foramen Foramen _____________ Foramen ____________ Foramen _____________

Sphenoid Optic Components ____________________ –Groove between Anterior body and lesser wings ___________________ –Hole between anterior body and lesser wings ___________________ –Space lateral to optic foramen between lesser and greater wings

Ethmoid Bone Small bone lying primarily below floor of cranium. Articulates with 2 cranial bones. _________________ –Horizontal portion ________________ –Superior projection from cribiform plate into frontal bone

More Ethmoid _________________ –Downward projection forms nasal septum ___________________ –Suspend from cribiform ___________________ –Downward projection from labyrinth

Sutures Areas of cranial fusion –Synarthrodial _______________ –Fuses Parietal to Frontal bone _______________ –Fuses right and left Parietal ________________ –Fuses Parietal to Occipital _________________ –Fuses Parietal to Temporal

Fontanels Membrane area as a Child Anterior Posterior Sphenoid (2) Mastoid (2)

Suture Articulations Adult _______________ –Frontal and parietals _______________ –Occipital and parietals _______________ –GW of sphenoid, temporal, parietal, frontal ________________ –Temporal, occipital, parietal