Lecture 7 - Circulation brain Flashcards
Arteries of the brain
Vertebral aa.
Internal carotid aa.
Middle meningeal aa.
Internal carotid artery enters the skull via ____
The carotid canal
Passes ____ and ____ through the cavernous sinus of the sphenoid body
anteriorly, medially
Internal carotid aa is a division from what
Common carotid artery
Terminal branches of the ICA
Anterior cerebral a.
Middle cerebral a.
Pass through the transverse foramina of the first 6 cervical vertebrae
Vertebral arteries
VA perforate the ____ and ____ to pass through the _____ _____
dura, arachnoid, foramen magnum
VA unite anterior to pons to form what?
Basilar artery
Another word for posterior circulation of the brain
Vertebrobasilar arterial system
Basilar artery (3 things)
Lies close to the base of the skull
Divides into 2 posterior cerebral arteries
These join the ICA via the posterior communicating arteries
Name the cerebral arteries
Anterior, middle and posterior cerebral arteries
Ant. cerebral arteries supply?
Most of the medial and superior surfaces of the brain and frontal pole
Middle cerebral arteries supply?
Lateral surface of the brain and temporal pole
Post. cerebral arteries supply?
Inferior surface of the brain and occipital pole
Other name for cerebral arterial cycle
Circle of Willis
The circle of Willis is formed by: (5)
Posterior cerebral arteries Posterior communicating arteries Internal carotid arteries Anterior cerebral arteries Anterior communicating arteries
Principle vessel receiving blood from these venous sinuses
Internal jugular vein
If the jugular is occluded, who offers collateral circulation?
Angular vein, pterygoid plexus and suboccipital veins
Difference between veins and sinus
Veins = ability to change diameter Sinus = fixed diameter (no muscle layer)
Sinus that lies in the superior border of the falx cerebri
Superior sagittal sinus
Superior sagittal sinus originates at the crista galli and ends near the internal occipital protuberance at the junction of ?? (4)
Superior sagittal sinus, straight sinus, occipital sinus, and transverse sinus
Name of the junction of the four sinuses
Confluence of sinuses
Much smaller than the superior sagittal sinus
Runs in the inferior border of the falx cerebri and terminates in the straight sinus
Inferior sagittal sinus
Straight sinus is formed by the joining of ____ and ____
Inferior sagittal sinus and great cerebral vein
Runs infero-posteriorly along the line of attachment of the falx cerebri and the tentorium cerebelli
Will join the confluence of sinuses
Straight sinus
Usually the ____ transverse sinus is larger
RIGHT
Leaves the confluence of sinuses laterally along the occipital bones and the posteroinferior angles of the parietal bones
Will become the sigmoid sinus as they approach the petrous portion of the temporal bones
Transverse sinus
Sigmoid sinus (2 things)
Follows an S-shaped course in the posterior cranial fossa
Forms deep grooves in the temporal and occipital bones
The sigmoid sinus continues inferiorly to the ____ ____ to become the internal jugular vein
Jugular foramen
Lies in the attached border of the flax cerebelli ending superiorly in the confluence of sinuses
Communicates with the internal vertebral venous plexus
Occipital sinus
Location of the cavernous sinus
Middle cranial fossa
Bilaterally on each side of the sella turcica
Extends from the superior orbital fissure anteriorly to the apex of the petrous portion of the temporal bone posteriorly
Cavernous sinus
The cavernous sinus receives blood from? (4)
superior ophthalmic vein
inferior ophthalmic vein
middle cerebral vein
sphenoparietal sinus
Content of cavernous sinus
Internal carotid artery
Carotid plexus of sympathetic nerves
Abducens nerve (CVI)
Ensheathed in lateral wall of cavernous sinus
Occulomotor nv. (III)
Trochlear nv. (CIV)
Trigeminal nv. (CV1 and sometimes CV2)
Runs from the posterior ends of the veins of the cavernous sinus to the transverse sinus to then curve to the sigmoid sinus
Lies in the anterolateral portion of the tentorium cerebelli
Attaches to the petrous portion of the temporal bone
Superior petrosal sinus
Also begins at the posterior ends of the veins of the cavernous sinus inferiorly
Runs between the petrous portion of the temporal bones and the basilar portion of the occipital bone
Inferior petrosal sinus
Drains the lateral cavernous sinus directly into the origin of the IJV
Inferior petrosal sinus
Basilar plexus
Connects inferior petrosal sinus to internal vertebral venous network
Emissary veins
Connects dural venous sinuses with veins outside the cranium
Arachnoid granulation
Collection of arachnoid villi
Prolongation of arachnoid that protrude through the meningeal layer of the dura into the dural venous sinuses
Will affect the transfer of CSF to the venous system
location of arachnoid granulation
Usually found in areas of the superior sagittal sinus and transverse sinus
Structurally adapted to transport CSF from the subarachnoid space to the venous system
Arachnoid granulation
Review the p.44 of ppt
Summary of the formation, circulation and absorption of CSF
