Neuroanatomy Flashcards
Which bones make up the anterior cranial fossa?
frontal bone
ethmoid bone
lesser wing of sphenoid bone
Where does the ACF lie over?
superiorly over the nasal and orbital cavities
What does the ACF accommodate?
anteroinferior portions of the frontal lobes of the brain
Where is the crista galli (latin for cock’s comb)?
Midline of the ethmoid bone
Where is the cribriform plate?
Either side of the crista galli
What is the cribriform plate and what does it contain?
a sheet of bone seen either side of the crista galli which contains numerous small foramina
these transmit olfactory nerve fibres (CN I) into the nasal cavity
Also contains anterior and posterior ethmoidal foramen
What does the anterior ethmoidal foramen transmit?
transmits the anterior ethmoidal artery, nerve and vein
What does the posterior ethmoidal foramen do?
transmits the posterior ethmoidal artery, nerve and vein
The cribriform is the thinnest part of the ACF and is most likely to fracture. What are the 2 clinical consequences of this?
Anosmia
CSF rhinorrhoea
What forms the body of the middle cranial fossa?
the body and greater wing of the sphenoid
squamous and petrous parts of the temporal bone
What forms the central part of the middle cranial fossa?
the body of the sphenoid bone
What does the central part of the MCF contain and what is its role?
sella turcica
holds the pituitary gland
What are the 3 parts of the sella turcica?
- tuberculum sellae
- pituitary fossa
- dorsum sellae
What is the sella turcica surrounded by?
the anterior and posterior clinoid processes
What is the tentorium cerebelli and what is attached to?
a membranous sheet that divides the brain.
attached at clinoid processes
separates occipital and temporal cerebral hemisphere from the cerebellum and infratentorial brainstem
Where are optic canals (foramina) and what do they transmit?
situated anteriorly in the middle cranial fossa
transmit the optic nerves (CN II) and ophthalmic arteries into the orbital cavities
What 4 foramina are lateral to the central part of the middle cranial fossa?
superior orbital fissure
foramen rotundum
foramen ovale
foramen spinosum
Where does the superior orbital fissure open and what does it transmit?
opens anteriorly into the orbit
transmits the oculomotor nerve (CN III), trochlear nerve (CN IV), ophthalmic branch of the trigeminal nerve (CN V1), abducens nerve (CN VI), opthalmic veins and sympathetic fibres
Where does the foramen rotundum open and what does it transmit?
opens into the pterygopalatine fossa
transmits the maxillary branch of the trigeminal nerve (CN V2)
Where does the foramen ovale open and what does it transmit?
opens into the infratemporal fossa
transmits the mandibular branch of the trigeminal nerve (CN V3) and accessory meningeal artery
Where does the foramen spinosum open into and what does it transmit?
opens into the infratemporal fossa
transmits the middle meningeal artery, middle meningeal vein and a meningeal branch of CN V3
What does the carotid canal transmit and where is it?
located posteriorly and medially to the foramen ovale
Internal carotid artery
Deep petrosal nerve
What junction does the foramen lacerum mark and what is it filled with in life?
sphenoid, temporal and occipital bones
filled with cartilage, only pierced by small blood vessels
What bones make up the posterior cranial fossa?
the occipital bone and the two temporal bones