Dental Science Bones of the Skull

how many cranial bones are there

8

function of the 8 cranial bones

cover and protect brain

2, paired, R/L

parietal bones

forms most of the top & upper sides of skull

parietal bones

sutures of the parietal bone

• sagittal

• coronal

• squamosal

• lamboidal

where 2 parietal bones meet at midline

sagittal suture

parietal bone articulates w/ frontal bone

coronal suture

parietal bones articulate w/ temporal bone

squamosal suture

parietal bone articulates w/ occipital bone

lamboidal suture

related structure of parietal bone

fontanelle

babys soft spot

fontanelle

where parietal bones and frontal bone have not joined yet

fontanelle

forms the forehead, part of the floor of the cranium, most of the root of orbits, part of nasal cavity

frontal bone

suture related to frontal bone

coronal suture

related structures of frontal bone

2 frontal sinus cavities

where are the frontal sinus cavities located

one above each eye

forms the back and base of cranium

occipital bone

suture related to occipital bone

lamboidal suture

related structure of occipital bone

foramen magnum

where spinal cord, blood vessels, ligaments, nerves pass through the cranium

foramen magnum

forms the side and base of cranium

temporal bones

suture related to temporal bones

squamosal

related structures of temporal bones

• external auditory meatus

• mastoid process

• glenoid fossa

• styloid process

external opening to ear canal

external auditory meatus

projection of bone behind the ear

mastoid process

contain airspaces that communicate w/ the inner ear

mastoid process

where the mandible articulates w/ temporal bone

glenoid fossa

extends from the underside of temporal bone

styloid process

sharp projection on temporal bone

styloid process

parts of sphenoid bone

• body

• greater wings

• lesser wings

• sphenoid sinus

• pterygoid process

• sella tursica

parts of pterygoid process

• lateral plate

• medial plate

articulate w/ temporal, frontal, zygomatic bone, forms part of orbit

greater wings of sphenoid bone

articulate w/ frontal, ethmoid, forms part of orbit

lesser wings of sphenoid bone

air-filled spaces of sphenoid bone

sphenoid sinus

extends downward on sphenoid bone

pterygoid process

ends in a hook-shaped hamulus

medial plate of pterygoid process

fossa where the pituitary gland sits

sella tursica

forms the floor of the cranium, the orbit, & nasal cavity

ethmoid bone

very complex bone

ethmoid bone

honeycomb shaped

ethmoid sinuses

formed by 2 plates

ethmoid bone

what 2 plates are the ethmoid bone formed by

• perpendicular plate

• cribiform plate

• crista galli?

vertical

perpendicular plate of ethmoid bone

horizontal

cribiform plate of ethmoid bone

6 total - 3 on each side

auditory ossicles

what are the auditory ossicles

• incus

• malleus

• stappes