Neurocranium bones?
- frontal
- parietal
- occipital
- temporal
- sphenoid
- ethmoid
How many bones in the skull? How many ‘associated’ bones?
-22 bones in the skull, 7 associated bones
Viscerocranium bones?
-mandible
-maxilla
-zygoma
-vomer
-lacrimal
-nasal
-palatine
inferior nasal concha
Calvaria (cranial vault) made up of?
- frontal, parietal & occipital bones
- bones formed by intramembranous ossificiation
- convex shape resists impact
What are fontanelles for?
- allow for passage of head through birth canal & accommodate growth of brain
- cranial bones do not articulate in the newborn
- soft spots (fontanelles)= membrane covered parts of the skull where sutures form, usually exist until about 7-19 months
- bulging or tense fontanelles may= increased intracranial P
What are the 3 cranial fossae?
-anterior, middle, posterior
What is the anterior fossa?
-anterior: frontal bone, crista galli & cribiform plate of ethmoid & lesser wings of sphenoid; contains frontal lobe & CN#1
What is the posterior fossa?
-posterior: sphenoid, temporal & occipital bones; contains occipital lobe, cerebellum, brainstem; number of ‘holes’ namely foramen magnum, hypoglossal canal, jugular foramen & internal auditory meatus
What is the middle fossa?
-middle: sphenoid & temporal bones; contains sella tursica, chiasmic groove, optic canal, superior orbital fissure, foramen rotundum, foramen ovale, foramen spinosum, foramen lacerum & cavernous sinus; structures provide for pituitary, optic chiasm, optic n., internal carotid artery & CNs III, IV, V1, V2 & VI; temporal lob of brains rests in middle fossa
Where can sinuses be found?
- ethmoid
- sphenoid
- maxilla
- frontal
- temporal (mastoid air cells)
- all are potential sites of infection
What does the mandible articulate with?
- temporal bones at the tempomandibular joint
- 1/5 of facial injuries involve mandibular fracture
What does the mandible hold? What n. are the gums and teeth innervated by?
- holds lower row of teeth in gomphosis joint at alveolar processes
- gums/teeth innervated by inferior alveolar n.
Temporomandibular joint is what kind of joint? Between what? Innervated by what n.?
- synovial jt with an articular disc
- articulation is b/w condylar portion of the mandible & mandibular fossa & articular tubercle of temporal bone
- innervated by mandibular branch of trigeminal n.
Hyoid bone is what kind of bone? Suspended from what? Attachment point for what?
- U-shaped bone
- suspended from temporal bone by stylohyoid ligaments from styloid processes of temporal bones
- has a body, 2 lesser cornua, & 2 greater cornua
- only bone in the human body that does not articulate with any other bone
- attachment point for muscles responsible for speech & swallowing
The bony orbit is made up of what bones?
- frontal
- maxillary
- ethmoid
- sphenoid
- lacrimal
- zygomatic
- palantine
Nostrils open up into the?
nasal cavity
The lateral wall of the nasal cavity has?
bumpy projections, conchae (turbinates)
The names of the conchae?
-superior, middle & inferior conchae
Superior & middle are made up of what bones? Inferior?
- superior and middle conchae are part of the ethmoid bone
- inferior conchae are individual bones
Roof of the nasal cavity contains receptors from what nerve?
Olfactory n.
Nostrils separated by?
nasal septum, which consists of perpendicular plate of the ethmoid, vomer, & cartilage; all covered w/mucosa
What are the conchae for?
warm & filter inhaled air, mucosa serves immune function by trapping foreign particles & exposing them to Ag presenting cells
What are the sutures?
- fibrous joints b/w bones of the skull
- coronal: b/w frontal & parietal
- sagittal: b/w parietals
- lambdoidal: b/w parietal & occiput
- squamosal: b/w parietal & temporal
- bregma: jxn of corona & sagittal sutures
- lambda: jxn b/w lambdoidal & sagittal structures
- pterion: jxn of frontal, parietal, temporal & sphenoid bones
- sutural ligs connect the cranial bones that are the remaining, unossified sheets of mesenchyme from intramembranous ossification
Muscles of facial expression?
- sphincter muscles: orbicularis oculi, orbicularis ori
- all other muscles may be considered dilator muscles
- innervated by facial n. (CN VII)
