Cranial fossa and nerves Flashcards
what lobes of the brain is found in the anterior fossa
frontal lobes
what feature can be seen inside the frontal bone but is not part of the cranial fossa
frontal air sinus
why is the frontal air sinus not considered within the cranial fossa
it lies within the frontal bone not inside the skull cavity
what is the name of the bony ridge formed by the frontal bone that provides attachment for the dura mater
crista gali
the cribriform plate is part of the _____ bone
ethmoid
why lies of the superior surface of the cribriform plate
olfactory bulbs
describe the path of the olfactory nerves
project up from nasal cavity through the cribriform plate to join the olfactory bulb (CN I)
what bone other than the frontal contributes to the anterior fossa of the skull
sphenoid bone
what bone contains the optic canals
sphenoid bone
the optic canals allow what to pass between the orbit and the inside of the skull
optic nerves (CN II) and the ophthalmic artery
what bone forms the orbital fissures
sphenoid bone
what foramina are found in the sphenoid bone
orbital fissures
foramen rotundum
foramen ovale
foramen spinosum
what nervous structure sits on the floor of the middle cranial fossa
trigeminal nerve forms a large ganglia that sits on the floor of the middle cranial fossa
what are the 3 divisions of the trigeminal nerve
ophthalmic (CNV1)
maxillary (CNV2)
mandibular (CNV3)
V1 is what modality
sensory
V1 passes through what cranial fossa to reach the orbit
superior orbital fissure
V2 is what modality
sensory
V2 passes through what foramen to pass towards the maxilla
foramen rotundum
V3 is what modality
motor and sensory
V3 goes through what foramen to reach where
foramen ovale to reach the infratemporal fossa
what nervous structures pass through the foramen ovale
otic ganglion
CN V3
lesser petrosal nerve
where exactly does the otic ganglion sit
sits at the exit of the foramen ovale in the infratemporal fossa
what structures pass through the foramen ovale
otic ganglion CN V3 accessory meningeal artery lesser petrosal nerve emissary veins
what artery is found in the foramen ovale
accessory meningeal artery
the foramen spinosum carries what artery
middle meningeal artery
the middle meningeal artery is a branch of what
maxillary artery
the middle meningeal artery supplies blood where
dura
what foramen allows the internal carotid artery to enter the middle cranial fossa
foramen lacerum
what artery is found in the foramen lacerum
internal carotid artery
what lobes of the brain lie in the middle cranial fossa
temporal lobes
what foramen are found in the middle cranial fossa
foramen rotundum
foramen ovale
foramen lacerum
foramen spinosum
the internal carotid artery enters the skull via what canal
carotid canal
the internal carotid artery enters the skull via the carotid canal then does what
turns away from the canal and enters the top of the foramen lacerum
describe the path of the internal carotid artery upon entering the foramen lacerum
does not pass all of the way through the foramen lacerum (small blood vessels traverse the length)
the internal carotid artery does not pass all of the way through the foramen lacerum. It then lies either side of the body of what bone
sphenoid bone
the internal carotid artery lies either side of the body of the sphenoid bone where it will enter the _____ before contributing to the ____
cavernous sinus
circle of willis
describe the path of the internal carotid artery in the head
enters the skull via the carotid canal
turns and enters the top of the foramen lacerum
does not pass all of the way through the foramen lacerum (small blood vessels traverse the length of the foramen lacerum)
Then lies either side of the body of the sphenoid bone where it will enter the cavernous venous sinus before contributing to the circle of Willis
what bone contributes to the floor of both the middle and posterior cranial fossa
temporal bone
what bone forms most of the floor of the posterior cranial fossa
occipital bone
the posterior cranial fossa borders what foramina
jugular foramen
foramen magnum
the posterior cranial fossa forms what canals
hypoglossal canals
the jugular foramen is the starting point of what
internal jugular cein
the jugular foramen allows what structures to pass
internal jugular vein
glossopharyngeal nerve
vagus nerve
accessory nerve
the foramen magnum allows the passes of what
start of the spinal cord and its meninges
vertebral arteries
spinal part of the accessory nerve
the hypogossal canal allows what to exit the skull
hypoglossal nerve
where does the cerebellum lie
posterior cranial fossa
the jugular foramen is between what 2 bones
occipital and temporal
in the posterior cranial fossa there is a groove for what
sigmoid dural venous sinus
the foramen magnum is in what bone
occipital
the hypoglossal canals are in what bone
occipital
the optic canal is in what bone
sphenoid
the foramen ovale is in what bone
sphenoid
the foramen rotundum is in what bone
sphenoid
where does the internal acoustic (auditory) meatus sit
petrous part of the temporal bone
the internal acoustic meatus allows what to exit the cranial cavity and enter the temporal bone
facial nerve and the vestibulocochlear nerve
name the cranial nerves
I - olfactory II - optic III - oculomotor IV - trochlear V - trigeminal VI - abducent VII - facial VIII - vestibulocochlear IX - accessory X - vagus XI - glossopharyneal XII - hypoglossa
what nerve provides the sense of smell
olfactory
what part of the olfactory nerve is seen on the surface of the brain
olfactory bulb and tract - not the nerves themselves
describe the path of the olfactory nerve
passes from the mucosa in the nose through the cribriform plate to synapse in the olfactory bulb
the olfactory nerve is an outgrowth of what
telencephalon
the olfactory tracts go from the olfactory bulb to where
prepiriform area of amygdala (primary olfactory cortex)
where is the primary olfactory cortex
prepiriform area of amygdala
the olfactory nerve is the only sensory system that is not relayed through the
thalamus
the optic nerves form a ____ where fibres from each eye will cross to the other side of the brain
optic chiasm
where do the optic tracts run
optic chiasm to other areas of the brain (lateral geniculate body of thalamus) then striate area (visual cortex)
where do fibres of the optic tract run from the thalamus
occipital lobe to be processes in the visual cortex
where is the visual cortex
occipital bone
the optic nerve is an extension of what
diencephalon
describe the route of the optic nerves
retina through the optic canal to form a chiasm then optic tracts
90% of fibres of the optic nerves go to the ______ of the thalamus
lateral geniculate body of the thalamus