Lecture 6: Skull Flashcards
Optic Canal
CNII (Optic Nerve)
Superior Orbital Fissure
CNIII (Oculomotor)
CNIV (Trochlear)
CNVI (Abducens)
CNV–> V1 branch
Foramen Ovale
V3 –> Mandibular branch of the trigeminal nerve
Foramen Spinosum
Middle Meningeal Artery
Internal Carotid Artery
Enters the cranial vault via the CAROTID FORAMEN, passing through the BONY CANAL and entering into the calvaria via the CAROTID CANAL.
CNVII (Facial)
Enters the INTERNAL AUDITORY MEATUS.
Exits via the STYLOMASTOID FORAMEN.
CNVIII (Vestibulocochlear)
Enters in the INTERNAL AUDITORY MEATUS.
Exits via the EXTERNAL AUDITORY MEATUS.
Jugular Foramen
CNIX (Glossopharyngeal)
CNX (Vagus)
CNXI (Spinal Accessory)
***All 3 exit from here.
CNXI (Accessory)
Enters via the FORAMEN MAGNUM.
Joins the cranial branches and exits via the JUGULAR FORAMEN.
CNXII (Hypoglossal)
Exits via the HYPOGLOSSAL CANAL.
What space harbors the bulk of the CSF?
Subarachnoid
What two major pairs of arteries provide blood supply to the brain?
Right and Left Internal Carotid Artery.
Right and Left Vertebral Arteries.
Where do the common carotid arteries bifurcate?
In the neck, just below the angle of the jaw.
What areas does the ECA supply?
face, scalp, and meninges covering the brain
Describe the path of the ICA
They ascend and travel through the carotid canal, enter the cranial vault alongside the cavernous sinus. At this point , they make a hairpin turn backwards and continue on as the middle cerebral artery and anterior cerebral arteries.
What is the first branch of the ICA?
The ophthalmic arteries, which branch off near the apex of the hairpin turn.
Where do the right and left vertebral arteries originate from?
Subclavian arteries.
Describe the path of the vertebral arteries
They enter the vertebral foramen bilaterally at the C6 level and travel upward through these foramen, entering the skull via the foramen magnum.
The two join at the junction of the medulla and pons to form the BASILAR ARTERY.
What can occur if there is head trauma in the region of the middle meningeal artery?
Bleeding into the epidural space can occur.
**This is a neurological and neurosurgical emergency with death occurring within a few hours if undiagnosed and untreated.
Why is the circle of willis important?
It provides the possibility for collateral flow if one or more of the four major arteries supplying the brain are obstructed or occluded.
What composes the Circle of Willis?
It consists of the posterior cerebral arteries connected to the internal carotid arteries via the posterior communicating arteries.
The anterior A1 segment of the anterior cerebral arteries and the anterior communicating artery complete the Circle of Willis.
What can result of you occlude any of the major sinuses of the brain?
Seizures, tissue injury, or blockage of the CSF circulation.
What allows communication between the 3rd and 4th ventricles?
Cerebral Aqueduct (Aqueduct of Sylvius)
What allows communication between the lateral ventricles and the midline third ventricle?
Interventricular Formamen of Monro.