Anatomy Lab 2 Flashcards
Which lobe does the anterior cranial fossa contain?
Frontal lobe
What is the crista galli?
Point of attachment for the falx cerebri
Where does cranial nerve I (oflactory) nerve enter?
Cribriform plate of the ethmoid bone
Where does cranial nerve II enter?
Optic canal (small holes below cribriform plate
What exits via the superior orbital fissue?
Cranial nerve 3, 4 and 6
What enters via the superior orbital fissure?
V1 (opthalamic)
What enters via the foramen rotundum?
V2
What enters via the foramen ovale?
V3
What travels via the foramen spinosum?
Middle meningeal artery
Describe where the divisions of the trigeminal nerve enter.
V1 - superior orbital fissure
V2 - foramen rotundum
V3 - foramen ovale
What is the foramen magnum function?
Passage of medulla, vertebral arteries and spinal roots of XI
What exits the jugular foramen?
Internal jugular vein, cranial nerves IX, X and XI
Which cranial nerves travel via the internal auditory meatus?
7 and 8
What travels in the hypoglossal canal?
Cranial nerve 8
Superior sagittal sinus
Of the cranial vault (pits formed by arachnoid granulations)
Transverse sinuses
Run transversely to where tentorium attached to occipital bone
Sigmoid sinus
Drains transverse sinus down into internal jugular vein
Confluence of the sinuses
Where the straight sinus and superior sagittal sinus drain into the transverse sinus
Cavernous sinuses
Blood spaces on either side of pituitary fossa enclosed by dura
Blood from inferior parts of brain drains here
Superior petrosal sinus
Runs along superior border of petrosal part of temporal bone
Connects the cavernous sinuses to the transverse sinuses
Inferior petrosal sinus
drains the cavernous sinus into the IJV
What is the tentorial incisure/notch?
Gap in the tentorium through which the brainstem passes in order to connect to the cerebral hemispheres
What structures pass through the tentorial incisure/notch?
Midbrain of the brainstem
Posterior cerebral artery
Third cranial nerve - oculomotor
Which specific part of the cortex lies just above the tentorium and is therefore most likely to herniate through the tentorial incisure?
Medial part of temporal lobe - the uncus (olfactory sensation is in this area)
List the major divisions of the brain
Cerebrum: L+R hemispheres
Diencephalon: core of cerebral hemispheres (thalamus)
Brainstem: midbrain, pons, medulla
Cerebellum: 2 cerebellar hemispheres
What does the ICA give off?
Anterior cerebral arteries (connected by the anterior communicating artery)
Middle cerebral artery
What does the ACA supply?
Medial aspect of hemispheres - anterior 2/3rds
What does the MCA supply?
Almost all of the lateral surfaces of the hemispheres
What forms the posterior cerebral arteries?
Vertebral arteries join to form the basilar artery
Basilar artery divides at the level of the pons/midbrain junction to form the PCAs
What do the PCA supple?
Supply the medial aspect of the posterior 1/3rds of the hemispheres
Between which layers of the meninges is bleeding likely to occur if a vessel in the cerebral arterial circle of Willis is torn?
Blood will enter the subarachnoid space and be found in the CSF
Which cranial nerve is most likely to be damaged by a tumour growing in the pituitary fossa?
Optic nerve - lies in the chiasma immediately above the fossa
Give two possible effects of a fracture of the cribriform plate of the ethmoid bone.
Anosmia - loss of smell due to tearing of the tiny bundles of olfactory nerves passing from nose to olfactory bulb
Rhinorrhea - loss of CSF through the nose due to tearing of the meninges overlying the fracture
Meningitis may occur if infection invades at this site
Patient cannot close their left eye properly and dribbles from left corner of mouth - which cranial nerve?
Damage to facial nerve causing paralysis of muscles around the eye (orbicularis oculi) and around the mouth (orbicularis oris)
Patient cannot blink or flinch when a tissue is touched to the eye - which cranial nerve is damaged?
Sensation in the whole face, including the eye, is through the trigeminal nerve (V)
The nerve affected here would be the ophthalmic division (V1)
Infarct of a cerebral artery has destroyed most of the inferior part of the temporal lobe (affecting memory). What major cerebral artery is most likely to be involved?
PCA
What part of the ventricular system opens directly into the subarachnoid space?
Fourth ventricle via its lateral and medial aperture
Where does cranial nerve III originate?
Junction of midbrain and pons
Which nerve originates on the dorsal surface of the midbrain?
Trochlear - nerve 4
Which nerve is the only one to arise from the pons?
Cranial nerve 5
Which nerves arise at the ponto-medullary junction?
6, 7, 8
Where does the olfactory nerve run?
In the cribriform plate of the ethmoid bone before synapsing in the olfactory bulb
Where does the optic nerve run?
Enters via the optic canal
Anterior to pituitary fossa
Which nerves lie in the cavernous sinus?
3, 4, V1 and 6
What else runs within the cavernous sinus?
Internal carotid artery
Where does the trochlear nerve run?
Runs with free edge of the tentorium to reach cavernous sinus before exiting through the superior orbital fissure
Where is the trigeminal ganglion found?
Anterior surface of petrous part of temporal bone
Where do cranial nerves 7 and 8 exit?
Internal auditory meatus
Where do cranial nerves 9, 10 and 11 leave?
Jugular foramen
What travels in the hypoglossal foramen?
Hypoglossal nerve (12)
What major nuclei from the lateral walls of the third ventricle?
Thalamus and hypothalamus
