Flashcards in Session 2 - Meningeal Layers, Dural Folds amd Dural Venous Sinuses Deck (16):
What are the meninges? Name the layers.
3 membranous layers that surround and protect the brain.
Dura - tough fibrous membrane
Arachnoid - soft translucent membrane
Pia - microscopically thin, delicate, closely adherent to the surface of the brain
What are the two layers of the dura?
Periosteal - periosteum lining inner table of the skull
Meningeal - layer adjacent to the arachnoid
What are the two dural folds?
The falx cerebri attaches to what structure anteriorly?
What is the purpose of dural folds?
Help to stabilise the brain
Act as rigid dividers
In some cases, a rise in intracranial pressure (e.g. secondary to a bleed) can lead to compression of the brain and therefore herniation through which foramen?
What are dural venous sinuses?
Venous blood filled channels created by separation of the meningeal layer from the periosteal layer of dura.
Dural venous sinuses will eventually drain into what vein?
Internal jugular vein
What are bridging veins?
Veins that pass from the subarachnoid space to dural venous sinuses, passing through the subdural space.
Damage to bridging veins is normally responsible for what sort of haemorrhage?
Where does bleeding occur in the following types of haemorrhage; extradural, subdural, subarachnoid, intracerebral.
Extradural - between the periosteal layer of dura and the bone
Subdural - between the meningeal layer of dura and the arachnoid layer
Subarachnoid - between the arachnoid and pia
Intracerebral - within the brain tissue itself
Would an extradural haemorrhage be a venous or arterial bleed?
Would a subdural haemorrhage be a venous or arterial bleed?
Would a subarachnoid haemorrhage be a venous or arterial bleed?
Why can lumbar punctures be useful in diagnosing a subarachnoid haemorrhage?
In a subarachnoid haemorrhage blood leaks into the subarachnoid space, mixing with cerebrospinal fluid. A lumbar puncture samples the CSF so can identify the presence of blood.