the skull - frontal and parietal Flashcards
how many bones in the adult skeleton
206
how many bones in the skull
29
basic bone divisions of the skull
bones of head (21)
ear ossicles (6 total, 3 on each side)
mandible
hyoid
skull**
entire structure, including the mandible
cranium (plural = crania)**
skull excluding the mandible
calvarium
cranium without the face
calotte**
calvarium without the base (top part of the skull literally just the scalp)
neurocranium**
bones that protect the brain, brain case
splanchnocranium/viscerocranium**
bones of the face (including the mandible)
accessory bones
ear ossicles & hyoid
extrasutural (wormian) bones**
irregular bones that occur along some sutures
prevalent along lambdoid suture (back base of skull)
paired bone
one on each side of the midsagittal plane
unpaired
cross the midsagittal
some unpaired bones fused from paired bones in childhood
cranial sutures
joints of interlocking, sawtooth-like articulations
don’t fuse, but obliterate together
no movement
frontonasal suture**
between frontal and nasal bones
zygomaticomaxillary sutures**
between the zygomatic and maxillary bones
sagittal suture**
passes along sagittal plane, joins left and right parietal bones
coronal suture**
passes along coronal plane
posterior suture of frontal bone
joins frontal and parietal bones
metopic (frontal) suture**
passes along midline of front bone between unfused frontal halves
not present in adults
lambdoid suture**
joins parietal and occipital bones
looks like a lambda
squamous suture**
joins temporal and parietal bone
different from other cranial sutures
bones overlap rather than interdigitate
basilar suture**
joins sphenoid and occipital bones on cranial base
good aging criteria bc it fuses between 18-25 years
types of sinuses
frontal, ethmoidal, maxillary, sphenoidal (top to bottom)
endocranium
what houses the brain
3 cranial fossae
anterior, middle, posterior
anterior cranial fossa
frontal lobes and cerebral cortex
middle cranial fossa
temporal lobes and cerebral cortex
posterior cranial fossa
cerebellum
frontal bone**
unpaired
formed in embryo from two ossification centers
fuses by age 2 at metopic suture
superciliary arch**
brow ridge
houses frontal sinuses
more prominent in males
glabella**
midline point of the superciliary arch
supraorbital margin**
superior border of the eye orbit
kind of outer corner
supraorbital foramen/notch**
hole = foramen, notch = incomplete
top of eye socket
zygomatic process**
lateral and anterior corners of frontal bone
lateral extent of brow ridge
site of suture with zygomatic bone
sticks out bc its a process
how many bones in ear ossicles
6 (3 on each side)
layers of neurocranial bones
3 layers = trilaminar
outer layer = tabula externa
middle layer = diploë
inner layer = tabula interna
middle layer of neurocranium
diploë (cancellous/trabecular bone w/ red bone marrow)
outer layer of neurocranium
tabula externa (cortical/compact bone)