Meninges and Blood Vessels (6A part 2) Flashcards
What are the two layers of the dura mater?
- Periosteal layer
2. Meningeal layer
What is the outermost meningeal layer? What does it attach to?
Dura mater ; it is attached to the interior surface of the skull
What structures are found between the two layers of the rural mater?
Venous sinuses (including superior sagittal and lateral sinuses)
Which layer is found deep to the dura mater?
Arachnoid mater
What space is found between the dura mater and arachnoid mater?
Subdural space
What meningeal layer is adherent to the surface of brain and thus is the deepest layer?
Pia mater ; separates the brain from the CSF in the subarachnoid space
Where is the epidural space located?
Between the skull and dura mater
What space is between the arachnoid mater and Pia mater? What is found in this space?
Subarachnoid space. It is filled with CSF
What two spaces in the meninges are potential spaces, i.e. they do not exist under normal circumstances?
- Epidural space
2. Subdural space
Which space is likely to have an arterial bleed?
Epidural space. (Esp after injury that fractures the skull, the middle meningeal artery may bleed –> epidural bleed; may separate the dura from the skull)
What space usually has venous bleeds into it?
Subdural space (bridging veins connecting the Dural venous sinuses may rupture)
What kind of injury may cause a subdural bleed?
Things causing shear, like shaking the head. Often a cause of death in “shaking baby syndrome”
Other than CSF, what resides in the subarachnoid space?
Large blood vessels positioned at the base of the brain and surrounding it. Rupture may lead to blood in the Subarachnoid space
What are two possible causes of a subarachnoid hemorrhage or subarachnoid hematoma? (I.e. Blood in the subarachnoid space)
Stroke or rupture of arterial aneurysm
What two structures are formed by the dura mater that help separate different compartments of the brain?
- Falx cerebri
2. Tentorium cerebelli
What does the falx cerebri partially separate?
The right and left hemispheres of the brain
What venous sinus runs along the superior border of the falx cerebri?
Superior sagittal sinus
What two areas does the tentorium cerebelli separate?
Middle cranial fossa from the posterior cranial fossa (which is also known as infratentorial compartment, which contains the cerebellum and brainstem)
What two nerves innervated the dura mater in order to sense cranial swelling?
- Meningeal branch of trigeminal n. (V) - Ant. and middle cranial fossae
- Vagus n. (X); (meningeal branches)
Although the spinal cord is covered by meninges very similarly to the brain, which two layers proceed out into the peripheral nerves?
- Dura mater
2. Arachnoid mater
What does the dura mater form when in a peripheral nerve?
Epineurium
What does the arachnoid mater form when in a peripheral nerve?
Perineurium
What two major pairs arteries serve the brain?
- Internal carotid a. (right and left)
2. Vertebral a. (right and left)
Which arteries (one on each side) supply the face, scalp, and the meninges overlying the brain?
External carotid ; ( common carotids bifurcate into internal and external at the level of the angle of the jaw)
What is the first branch off the internal carotid arteries, just at the apex of the hairpin turn they take after entering the cranium throughou the carotid canal?
Ophthalmic a.
What two arteries do the internal carotids branch into after the hairpin turn (when headed back towards the dorsum)?
Middle and anterior cerebral a.
What artery does the vertebral artery brach off of ( this happens on both sides)?
Subclavian artery
At what level do the vertebral arteries enter the vertebral foramen?
At the C6 level
What artery do the right and left vertebral arteries fuse to form? At the junction of what two structures does this occur?
Basilar a. Occurs at the junction of the pons and medulla
What are the terminal branches (right and left of same name) of the basilar artery? (Hint: involved in Circle of Willis
Posterior cerebral a. (Right and left)
Which arteries connect the internal carotids to the posterior cerebral a., thus forming the posterior part of the Circle of Willis?
Posterior communicating arteries. (There is one on each side)
What artery connects the right and left anterior cerebral arteries, completing the anterior portion of the Circle of Willis?
Anterior communicating artery; (there is only one of these, in contrast to the post. communicating arteries in which there is one on each side
What is the functional significance of the Circle of Willis?
Allows for collateral blood flow to one or more of the major brain arteries is one is obstructed or occluded.
Which artery supplies the lateral side of the cortex?
Middle cerebral artery
Which artery supplies the medial/interior aspect of the cortex?
Anterior cerebral artery
Which artery supplies the cortex on the inferior, posterior surface and also the interior side of the cortex?
Posterior cerebral artery
What 2 venous sinuses draino into the straight sinus, located at the inferior, posterior margin of the falx cerebri?
- Great cerebral vein of Galen
2. Inferior sagittal sinus
What two venous sinuses merge to form the confluence of sinuses?
- Straight sinus
- Superior sagittal sinus
(Transverse sinuses, one on either side also communicate with the confluence; these should drain the sinus though)
Occlusion of major venous sinuses may cause what?
Seizures, tissue damage, or CSF backup
