3.2 Meninges Flashcards
leptomeninges and their importance
pia and arachnoid mater
meningitis affects
what’s contained in subarachnoid space?
-CSF (pressure keeps arachnoid and Pia separate)
-cerebral vessels (supply and drain brain)
cerebral vessels
-arteries from vertebral and internal carotid arteries
-veins drain into dural venous sinuses
can you pull the pia mater away from brain surface?
no
arteries supplying menInges
meningeal arteries, between periosteal dura mater and inner table of skull
what is a dural fold?
meningeal layer of dura mater comes away from periosteal layer and extends
tentorial notch
tentorium cerebelli opens at top for brainstem
which brain movement does fall cerebri stabilise?
left to right and vice versa
which brain movement does tentorium cerebella stabilise?
up and down
where are the cavernous sinuses?
in middle cranial fossa, either side of sphenoid bone
how does inferior sagittal sinus meet superior one?
via straight sinus, meet at confluence of sinuses
2 types of venous connection between DVS and other structures
- cerebral veins in subarachnoid space via bridging veins to DVS (intracranial)
- scalp veins via emissary veins to DVS (extra cranial)
path of bridging veins to DVS
through subdural space
path of emissary veins to DVS
through skull- especially holes in parietal bone
symptom progression of extradural haemorrhage
head injury, headache and alert, 1 HOUR LATER = deterioration of neurological function
lucid interval
time between head injury causing extradural haemorrhage and loss of neurological function where patient seems ‘normal’
explain the appearance of an extradural haemorrhage
-lentiform
-rupture of middle meningeal artery strips periosteal dura away from inner table of bone
-blood fills space
-strong adherence of periosteal dura at sutures prevents further lateral expansion
symptoms of subdural haemorrhage
-headache
-less rapid deterioration
-pressure and blood increase over time
where is a subdural haemorrhage?
between meningeal dura and arachnoid mater, can fill all way round that hemisphere of brain = crescent shape on CT
likely rupture location to cause subdural haemorrhage
where bridging vein joins wall of DVS
explain how subdural haemorrhage could occur in a minor head injury
elderly people have cortical shrinkage, puts tension on connection of cerebral vein to DVS so snaps more likely
typical feeling of subarachnoid haemorrhage
hit on head by bat
why headache sudden in subarachnoid haemorrhage?
blood irritates meninges
