Lec 3 Flashcards
Where is the tentorial notch. What does it make space for and what is a clinical problem it can cause?
Tentorial notch is at base of tentorium cerebelli.
It makes space for brainstem structures (midbrain sits there)
Since material is tight, can cause brain structures to squish against it if there is swelling or tumour.
Where do the transverse sinus and superior sagittal sinus run ?
What tissue forms them?
Transverse run between brain hemispheres at top.
Sagittal run between cerebellum and occipital lobe
Tissue = periosteal layer of the dura
What tissue forms the falx cerebri and tentorium cerebelli
meningeal layers of the dura fused together
Describe herniation in the brain.
When brain structures are pushed into areas that they don’t belong. Usually by swelling, tumour etc.
What is a subfalcine herniation? (Important for exam)
When brain is pushed into opposite hemisphere across the falx cerebri
what is a central herniation in the brain?
When diencephalon and midbrain are pushed downwards through tentorial notch
what is an uncal transtentorial herniation? (important for exam)
When part of the brain pushes under the tentorium cerebelli
What is a tonsillar herniation
where part of the cerebellum is pushed through the foramen magnum.
What is arachnoid mater and what is it adhered to?
What are arachnoid granulations?
Middle layer of the meninges.
Adhered to the inner surface of the dura (meningeal layer).
Arachnoid granulations are areas where arachnoid mater bulges through the dura. Allows cerebrospinal fluid to be absorbed into the venous system. Can maintain intracranial pressure
What is pia mater. What does it do?
Innermost layer of the meninges and adheres to the brain.
For nourishment (vascularized) structural support of nervous system.
What are potential spaces in the brain
What are the potential spaces in the brain?
spaces that could separate if pulled (e.g. if blood fills space), but stay closed otherwise.
Epidural space - Between skull and periosteal layer of the dura
Sub-dural space - between meningeal layer of dura and arachnoid
Some sources say the subarachnoid space is potential
What is actual space in the brain
Name 2 spaces
anatomical cavity that is filled with some substance or has purpose.
Sub-arachnoid space - between arachnoid and pia mater. Contain CSF, and is vascularized. Confirm
Sagittal space - separation of dural layers at falx cerebri
Describe an injury that would cause an epi-dural hematoma.
Can the hematoma cross the midline of the brain?
How fast does it spread and what looks like?
Fracture of temporal bone can cause rupture in middle meningeal artery (which runs between dura and skull).
Leads to hematoma between skull and periosteal layer of the dura. Therefore it can cross the midline because is outside of the the falx cerebri.
- Spread fast
- lens shape
- can cause herniations and death
Describe an injury that would cause an sub-dural hematoma.
Can the hematoma cross the midline of the brain?
How fast does it spread and what looks like?
What happens with an acute vs chronic one?
Bleeding between meningeal layer and arachnoid mater. Accellerations or decell that lead to shearing between layers of brain that tear blood vessels. Car accident or arterial aneurism (weak vessel bursts)
- not cross midline
- bleeding between meningeal layer of dura, can get into superior sagittal sinus
- Slow bleed (days or weeks)
- Crescent shape (like rind of melon)
- Acute (car crash), white appearance
- Chronic (bleeds slow/not immediate issue), more grey appearance less dense with blood.
- usually happens in older people
Describe an injury that would cause an Sub-arachnoid hematoma.
Can the hematoma cross the midline of the brain?
How fast does it spread and what looks like?
Commonly non-traumatic. Rupture of aneurism . OR could be traumatic brain injury.
cross midline?
Fast spreading because many large arteries are in subarachnoid space.
Can see bleeding around the brain (I think because it is continuous with surface of brain) (ask in tutorial)
Define Aneurism
Ballooning/dilation caused by weakening of blood vessel.
If burst, is a burst aneurism.
What is a herniation of the brain going under the tentorium cerebelli called?
What about a herniation of one side of the brain across the falx cerebri?
uncal transtentorial herniation
sub-falcine herniation
