Skull and Meninges Anatomy Flashcards
name the three foramens on the frontal aspect of the skull
supraorbital
infraorbital
mental foramen
what exits the supraorbital foramen?
V1 of the trigeminal
what exits the infraorbital foramen?
V2 of the trigeminal
what exits the mental foramen?
V3 of the trigeminal
what is the name of the location on the side of the skull where all the bones articulate?
pterion
what lies just under the pterion?
middle meningeal artery
what are the grooves for in the skull?
they house the middle meningeal vessels
what are the foveolae in the skull?
they are pits that are formed by the arachnoid granulations
what is the structure in an infant skull that has not fully formed yet?
anterior fontanelle
what age does the anterior fontanelle harden and close?
18-24 mos
if anterior fontanelle is sunken, what is it a sign for in baby?
dehydration
if anterior fontanelle is elevated, what is it a sign for in baby?
increased intracranial pressure…hydrocephaly/encephalitis
what is scaphocephaly?
premature closure of sagittal suture in infant leading to long narrow neurocranium
what is brachycephaly?
premature closure of coronal suture leading to short and wide neurocranium
what are the large locations that hold CSF in the brain called?
cisterns
where doe the arachnoid granulations penetrate to get into venous system?
the dura mater
what are the two layers of the dura mater?
outer periosteal and inner meningeal layer
when the two layers of the dura mater diverge, what do they form?
dural venous sinuses
when the inner meningeal layer of the dura mater converges with itself, what does it form?
partitions in the brain
name the two major partitions of the brain
falx cerebri and tentorium cerebelli
what does the falx cerebri divide?
separates the cerebral hemispheres
what does the tentorium cerebelli divdide?
occipital lobe and cerebellum
what is the tentorial notch?
U shaped margin of the tentorium cerebelli
what often occurs in the tentorial notch?
brain herniations
do the dural venous sinuses have valves?
no blood flow in any direction
name the six dural venous sinuses
superior sagittal inferior sagittal straight transverse sigmoid cavernous
what is the most important dural venous sinus?
cavernous
what lies in the middle of the cavernous sinus?
pituitary gland
what artery runs through the cavernous sinus?
internal carotid artery
name the five cranial nerves in the cavernous sinus
occulomotor (CNIII)
Trochlear (IV)
Trigeminal divisions V1 and V2
Abducens nerve (VI)
what other vessels can drain into the dural venous sinuses?
facial veins
if facial veins drain into venous sinuses then what can happen if infection involved?
cavernous sinus thrombosis
what causes an epidural hematoma?
rupture of meningeal artery
what is the shape of a epidural hematoma on CT?
biconvex lens like appearance
what causes a subdural hematoma?
rupture of cerebral veins
what is the shape of a subdural hematoma on CT?
crescent shape
what causes a subarachnoid hemorrhage?
rupture of cerebral artery
what are the signs of a skull bone fracture?
bilateral periorbital ecchymosis
hemotympanum
post auricular ecchymosis
why do you get the bruising signs around the eye and ear with skull bone fracture?
because the meninges are torn
name the three skull base fossas
anterior cranial
middle cranial
posterior cranial
what is the bony protrusion that houses the pituitary gland?
sella turcica
CNI
olfactory nerve
CNII
optic nerve
CNIII
occulomotor nerve
CNIV
trochlear nerve
CNV
trigeminal nerve
CNVI
Abducens nerve
CNVII
facial
CNVIII
vestibulocochlear
CNIX
glossopharyngeal
CNX
vagus
CNXI
spinal accessory
CNXII
hypoglossal
what nerve exits the cribiform plate?
olfactory nerve CNI
what nerve exits the optic canal?
optic nerve CNII
what nerves exit the superior orbital fissure?
CN III (occulomotor) CNIV (trochlear) CN V1 (trigeminall) CN VI (abducens)`
what nerve exits the foramen rotundum?
V2…maxillary division of trigeminal
what nerve exits the foramen ovale?
V3…mandible division of trigeminal
what nerves exit the internal acoustic meatus?
facial (VII) and vestibulocochlear (VIII)
what nerves exit the jugular foramen?
glossopharyngeal (IX), vagus (X), spinal accessory (XI)
what nerve exits the hypoglossal canal?
hypoglossal (XII)
is the cranial dura mater highly or lowly innervated?
very highly innervated
what nerves help innervate the cranial dura mater?
trigeminal nerve
vagus nerve
cervical nerves
in the cavernous sinus, what nerve lies just below the internal carotid artery?
CN VI (abducens)
