Download Bones of the Axial Skeleton

Bones of the Axial Skeleton
Skull – 22 bones (8 cranium
13 facial
And mandible)
Sutures: narrow joints/jagged line
Sinuses: chambers within bones
Of skull ( frontal bone
Ethmoid
Sphenoid
2 maxillary
Lining=mucus membrane
Sinusitis: inflammation
FCN: 1. connect w/nasal cavity
For drainage
2. reduce wgt of skull
3. resonate sound for voice
Cranium:
FCN: encloses and protects brain
Attachment site muscles of scalp
Lower jaw, neck and back
Formed by 8 bones:
1. frontal bone: anterior bone of skull above
eyes
a. orbits= eye sockets
b. supraorbital foramen: BV & N
c. frontal sinuses: within frontal bone
above each orbit
2. Parietal bones(2)
a. Sagittal suture: where they meet
b. Coronal suture: JCN with frontal bone
3. Occipital bone: forms posterior wall of and
floor of cranium
a. Lambdoidal suture: JCN of occipital and
parietal bones
b. Foramen magnum: large opening for
spinal cord
c. Occipital condyles: on either side of FM
i. Site of articulation with atlas(first
CV)
4. Temporal bones(2)
a. Inferior to parietal bones
b. Squamosal suture= JCN of P&T
c. External auditory meatus:inferior margin
d. Mandibular fossa: anterior to EAM
Articulation for mandible
e. zygomatic process: anterior extension
which joins to zygomatic bone
f. styloid process: pointy projection
i. anchors muscles of tongue
g. mastoid process: rounded projection
inferior surface anchors muscles of neck
Sphenoid Bone
Bat shaped( as seen from looking down and into
interior of cranium)
Anterior wall of cranium
Inferior lateral wall of cranium
Anterior to temporal bone
Optic foramen- for nerves that serve the eye
Inferior and superior orbital fissures – BV and nerves
*Sella turcica – the small depression, nook, to protect
and house the pituitary gland
Ethmoid bone
Anterior to sphenoid
Portion of orbital walls, posterior to lacrimal bones
 cribriform plate(cribrum =sieve)
perforated for nasal nerves
forms portion of anterior cranial floor
*crista galli – from the cribriform
for attachment of meninges of brain
 perpendicular plate – descends from cribriform
forms most of nasal septum
 superior and middle nasal conchae – scroll like
 froms lateral sides of nasal conchae
SINUSES
Chambers within the bone
Lined with mucous membrane
Filled with air
Sinuses (cont)
Fcn: drains fluids from nasal cavity
Reduce wgt of skull
Resonate sound from voice
Sinusitis – inflammation of mucous membrane in sinus
Sinus headache – pressure from fluids in sinuses