UNIT 5: Bones of the Skull Flashcards
skull =
all bones of the head
cranium =
skull to mandible
bones of the cranium can be divided into two groups
neurocranium
viscerocranium
neurocranium
aka cranial skeleton
forms a vault for the brain, floor of the neurocranium is called cranial base
visecerocranium
aka facial skeleton
forms the upper facial skeleton; inferior and anterior to the neurocranium
neurocranium consists of ___ bones
8
sutures are…
fibrous joints bw bones that make up the viscerocranium and the vault of the neurocranium
visceorcranoum consists of ____ bones and the ______
13
mandible
describe the frontal bone
ossifies in adulthood to form a single bone
dorms bony forehead, anterior to brain case and the roof of the orbital cavity
the frontal bone articulates w two bones of the viscerocranium
zygomatic bone via zygomatic process
nasal bone via nasal portion
parietal bones
large paired bones - 2 of them
form the greater portion of the superior and lateral surfaces of the cranium
join w other bones at the 4 largest sutures (sagittal, coronal, lambdoidal, squamousal)
constitutes bulk of cranial vault
occipital bone
forms the posterior and inferior surfaces of the brain case
articulates w temporal, parietal, and sphenoid bones of neurocranium
temporal bones
paired bones (2 of them) that form the lateral base and sides of the brain case
what does the temporal bone house?
the sensory mechanisms involved in hearing and equilibrium
what are the 4 parts of the temporal bone?
squamous =anterior and upper portion
tympanic = curved plate of bone
petrous = projects into skull base bw sphenoid and occipital
mastoid = posterior, external portion
ethmoid bone
complex, delicate structure at the core of cranium and facial skeleton
forms part of the walls of the cranial, nasal, and orbital spaces
sphenoid bone
very complex bone located at the base of the skull; significant contributor to cranial structure
what are the three important features of the sphenoid bone
greater wings
medial and lateral pterygoid plates
foramina
what are the three cranial fossae?
anterior
middle
posterior
anterior cranial fossa
anterior 1/3
houses the frontal lobes of the brain
floor formed by the frontal bone, crista galli, and cribiform plate of ethmoid bone, lesser wings of sphenoid
middle cranial fossa
contains temporal lobes of the brain
body and greater wings of sphenoid, squamous, and petrous portions of temporal bone
posterior cranial fossa
largest and deepest of the 3
contains occipital lobe, cerebellum and brainstem, floor contains foramen magnum (passageway of spinal cord)
basisphenoid, basiooccipital, petrous and mastoid portions of temporal bone, parietal and occipital
upper facial skeleton consists primarily of…
upper jaw and the oribital and nasal cavities
maxillae
paired (there are 2 of them), largest bones of the face (besides mandible)
contribute to roof of mouth, nose, upper dental arch
5 processes of the maxillae
zygomatic
frontal
orbital
alveolar
palatine
palatine bones
paired (2 of them)
posterior to maxillae
part of 3 cavities: nasal, orbital and oral
orbital plate of the palatine bone forms
small portion of medial orbit
horizontal plate of palatine bones forms
posterior 1/4 of hard palate
posterior nasal spine and nasal crest in floor
sphenoidal process of palatine bones articulates w
spehnoid
zygomatic bones
paired (2 of them) - articulate w maxilla, frontal, temporal, and sphenoid bones
4 processes of zygomatic bones
frontal
orbital
temporal
maxillary
Lacrimal bones
paired (2 of them); smallest facial bones
articulate w maxillae, frontal bone, ethmoid, and inferior nasal conchae (in nasal cavity)
medial wall in orbital cavity
lateral wall in nasal cavity
contains a depression that houses the nasolacrimal sac
nasal bones
paired (2 of them)
articulate w frontal, maxillae, perpendicular plate of ethmoid
meets nasal septal cartilage anteriorly
forms the bony bridge of the nose
inferior nasal conchae
paired (2 of them), thin, curved bones projecting from the lateral wall of the nasal cavity
largest of the 3 conchae (located inferior to middle nasal conchae of the ethmoid bone)
mucosal covering of all 3 conchae is
thick, richly vascularized
vomer
single bone
forms inferior and posterior portion of the nasal septum (medial wall)
articulates w sphenoid and perpendicular plate of ethmoid
mandible
single bone in adults (fuses during dev)
the skull is comprised of individual and paired bones that contribute to the _____ and _____
neurocranium
viscerocranium
_____ provide immovable joints bw bones inc the ______ _____ of the cranial vault
sutures
structural integrity
