Anatomy Lecture 45_Cerebral Vasculature and Meninges Flashcards
What are the 4 dural septa?
- Falx cerebri
- Tentorium cerebelli
- Falx cerebelli
- Diaphragma sellae
Describe the location of the Falx cerebri in the skull
Lies in the longitudinal fissure. Anteriorly it attaches to the frontal crest and crista galli. Posteriorily is attaches to the occipital protuberance and is continuous with the tentorium cerebelli. It generally lies in a sagital plane
Describe the location of the Tentorium Cerebelli in the skull
Lies in the posterior aspect of the of the skull seperating the cerebrum from the cerebellum. It lies in a mostly transverse plane
Describe the location of the Falx cerebelli in the skull
It lies inferior to the tentorium cerebelli. It seperates the cerebellar hemispheres and lies in a sagital plan
Describe the location of the diaphragma sellae in the skull
Covers the pituitary gland, nuff said
What is the arterial supply of the dura mater?
- External carotid > maxillary > middle meningeal artery. This provides most of the blood supply to the dura mater and all the later al blood
- Ethmoidal arteries > Anterior meningeal arteries
- Vertebral/occipital >posterior meningeal arteries
What innervates the falx cerebri and the Tentorium Cerebelli?
Branches of the opthamic nerve (CN V1)
What is an extradural (epidural) hematoma?
It is a collection of arterial blood between the skull and the the dura mater
What is a subdural hemoatoma?
It is the collextion of blood (typically venous) between the dura mater and the arachnoid mater
What causes a subaracnoid hemorrage?
Extravation of blood, typically arterial, into the subarachnoid space. This is most often caused by trauma but can also be caused by the rupture of an intracranial aneurysm
What is meningitis?
It is an infection of the meninges. It can be caused by bacteria (the most dangerouse), virus, or fungi. It can be diagnosed with a spinal tap. CSF will have high levels of protein, and leukocytes and low glucose.
What are meningiomas?
Tumors of the meninges. Often associated with abnormalities in chromosome 22. Treatment includes surgical removal or radiation.
What are the 4 parts of the Internal Carotid Artery (ICA)
1) Cervical Part, 2) Petrous Part, 3) Cavernosus Part, 4) Cerebral Part
What are the 5 branches of the Cerebral part of the ICA?
Opthalmic Artery Posterior communicating artery Middle cerebral artery Anterior cerebral artery Anterior choroidal artery
What are water shed areas in the Brain. What are their pros and cons?
Watershed area refers to areas of the brain whereblood supply is provided by distal regions of 2 ormore arteriesAdvantage: if one artery experiences blood flowinterruption, then the other artery can provideadequate blood supply to areaDisadvantage: when there is global reduction inblood flow to the brain, the perfusion of the braintissue in watershed areas is decreased and theseareas are more susceptible to ischemia and stroke
What is the importance of the cerebral arterial circle (Circle of Willis)?
Important anastomosis: When blood flow is reduced in either ICA or vertebro-basilar system, collateral circulation in Circle of Willis provides blood to deprived areas
What is the location of the superior sagittal sinus?
Runs on the superior surface of the falx cerebri. It begins at the crista galli and runs posterioraly to the confluence of sinus
What is the location of the inferior sagittal sinus?
Runs on the inferif surface of the falx cerebri. It terminates in the straight sinus
What is the location of the straight sinus?
It froms from the union of the posterior inferior sagittal sinus and the great cerebral vein. It runs inferior to the falx cerebri along the top of the tentorium cerebelli to the confluance of sinuses
Where is the confluence of sinuses, what does it receive and where does it drain?
It is a dilated space at the internal surface of the occipital protuberance. It receives the Superior, straight, and occipital sinuses. It is drained by the transverse sinuses
Where is the occipital sinus
It lies along the border of the falx cerebelli. It ends superiorally in the confluence of sinuses.
Where is the transverse sinus?
It travels lateral from confluance of sinuses and becomes the sigmoid sinus as it approches the temporal bone and then drains into the jugular vein
