Skull-Wilson Flashcards
What are the 8 bones of the neurocranium?
Temporal (2) Parietal (2) Frontal (1) Sphenoid (1) Ethmoid (1) Occipital (1)
Coronal suture
separates parietal and frontal
sagittal suture
??
lambdoid suture
???
bregma
lambda
can use stereotactic coordinates to do neurosurgery
parietal foramen
emissary vein: veins that go through the skull from the scalp and skin to communicate with meninges
- potential sites for the spread of infection
- they are valveless
skull at birth
same bone BUT
- 2 frontal bones (frontal suture which disappears in adult)
- anterior fontanelle (bregma); a soft spot in the baby’s skull
- posterior fontanelle (lambda)
these fontanella allow the brain to grow and expand and the skull can expand with hte brain
Premature fusion of the anterior and posterior fontanelle sutures
scaphocephaly: premature closure of the sagittal suture
acrocephaly: premature closure of coronal and lambdoid sutures; skull extends upwardly
can result in mental retardation
What is found in the anterior cranial fossa?
????
What is found in the posterior cranial fossa?
brainstem and ???
What is found in the middle cranial fossa?
temporal lobe of brain
3 bones of anterior cranial fossa
-frontal bone
2 frontal sinuses which can get infected and causes sinus headaches
-orbital plate: dome shaped; forms the roof
-sphenoid bone (lesser wing)
- ethmoid
- anterior clinoid process: attachment for the dural mater and dural reflection
- crista galli: cone of the rooster
- cribriform plate: CN I (olfactory nerve) goes from the brain and innervate the olfactory mucosa of the nasal cavity (nerves for smelling)
foramen cecum: an opening through which an emissary vein passes through
Transorbital lobotomy
altering people’s behavior typically if they are unruly, aggressive, antisocial
-a simplified version of the prefrontal operation
bones in the middle cranial fossa
2 bones;
-sphenoid bone (greater wing)
BODY
-sella turcica: the pituitary
-chiasmatic??? groove: 2 optic nerve come together at the optic chiasm
pituitary swelling will affect optic nerve
-posterior clinoid process
- squamous bone???
- petrous temporal bone (one of the densest bone in the body); vestibulocochlear apparatus is embedded in this bone; facial nerve travels through this bone (is often one of the places the facial nerve is damaged)
optic canal
when CN II travels
superior orbital fissure
crack where the CN III, IV, V1, and VI, travels
foramen rotundum
V2 (trigeminal nerve)
foramen ovale
V3
foramen spinosum
middle meningeal artery: artery that supplies the meninges
carotid canal
exit point of the carotid canal
where the internal carotid artery gains access to the brain
internal carotid artery enters the carotid canal medial to the styloid process
foramen lacerum
????
opening under carotid canal
no clinical significance
Posterior cranial fossa
3 bones:
- dorsum sellae
- petrous temporal bone
- occipital bone
- clivus
- foramen magnum
-internal occipital protuberance
groove for transverse sinus: venous sinus carrying blood away from brain to heart
groove for sigmoid sinus: jugular foramen
cerebellar fossa: hemispheres sit on this fossa NOT the vermis
internal acoustic meatus: where CN VII, VIII to enter the petrous temporal bone
jugular foramen: directly below the internal acoustic meatus; internal jugular vein goes through this
CN IX, X, XI (accessory nerve)
CN XI: roots of this nerve is found in the SC: they are lateral roots that go through the foramen magnum and exit through the jugular foramen; jugular foramen syndrome
hypoglossal canal: VII, VIII, IX, X, XI
Arnold Chiari Malformation
Type I: cerebellar fossa is very flat and the cerebellum has nowhere to sit and herniates through the foramen magnum
superior nuchal line
trapezius
SCM attach to
foramen magnum
accessory nerve and ???
stylomastoid foramen
CN VII (facial nerve) exits the skull through here to reach the muscles of facial expression
Zygomatic process of the temporal bone
????
mandibular fossa
articular eminence
condyle slides back and forth btw the fossa and eminence
occipital condyle forming joint with atlas
???
condylar canal (hypoglossal canal is more anterior)
???
the facial canal
CN VII as a long course which is completely surrounded by bone
which means if there is swelling of CN VII or facial canal you get compression of CN VII–> Bell’s palsy
lateral view of skull
BONES -frontal bone -sphenoid bone (greater wing) -parietal bone -temporal bone squamous portion mastoid process zygomatic process
zygomatic bone is part of viscerocranium NOT a bone of the neurocranium
-superior temporal line and zygomatic bone form the temporal fossa: includes the pterion where the bones of the skull have an intersection
pterion (THIN): intersection of temporal parietal, zygomatic, and frontal bone
groove for the middle meningeal artery: if you fx the skull at the pterion this vessel will be most likely damaged and you get bleeding (EPIDURAL HEMATOMA)
as the blood gets larger you get compression on the cortex and the incus herniates putting pressure on the ?????
infratemporal fossa
- area of the skull medial to the ramus of the mandible
- btw the axilla and the styloid process
- will find the pterygoid process and thus find the medial and lateral pterygoid plates
space between pterygoid process and maxilla
pterygomaxillary fissure
what foramen from the middle cranial fossa opens up into the pterygopalatine fossa?
foramen rotundum
VISCERAL CRANIUM
14 Bones
zygomatic (2) maxilla (2) nasal (2) palatine (2) lacrimal (2) inferior nasal concha (2) mandible (1) vomer (1)
maxilla
has several process
- frontal process
- zygomatic process
- alveolar margin: need to have teeth to have this margin; if teeth is removed the margin is reabsorbed
supraorbital foramen
infraorbital foramen
mental foramen
where V1, V2, V3 terminates into the face
Mandible
angle of mandible condyle neck of condyle ramus of mandible ramus process: -interiorly the coronoid process -posteriorly: condylar process
mandibular notch
mandibular foramen
nerve that provides sensory innervation to all of the teeth
?????
for the NVB of the mylohyoid nerve which innervates ??????
mylohyoid muscle
forms the floor of the mouth
hard palate
made up of 2 bones:
- most is maxilla
- horizontal process of the palatine bone
- incisive canal
- greater palatine foramen
- lesser palatine foramen
- primary palate fuses with a secondary palate
orbital bones
- lacrimal bone
- roof is the orbital plate
- laterally: sphenoid greater wing (can see this from a lot of angles)
- maxillary orbital surface
- infraorbital foramen where V2 becomes cutaneous in the middle of the face
- nasolacrimal canal: constantly recycling tears; communication between orbital and nasal canal
on the medial wall: anterior and posterior ethmoid foramen: where the vein and arteroes run?????
inferior orbital fissure, groove & canal: where the infraorbital nerve travel through the floor of the mouth
Nasal cavity
- perpendicular plate of the ethmoid
- ethmoid is PART OF THE NEUROCRANIUM but has processes that run to the viscrocranium
turn the head over
- vomer
- choana (posterior nares)
- medial/lateral pterygoid plate
nasal septum formed by
-vomer (plow; forms the bath)
-perpendicular plate of the ethmoid
cartilage??????
lateral nasal wall
ethmoid bone forming the middle????
