Meninges Flashcards
How is spinal epidural space different to epidural space of the brain?
The space is real in spinal cord but only a potential space in the brain.
Where does the pia mater end?
At the level of L1/2 at the conus medullaris
What is the filum terminalis?
Pia mater extends from the end of the conus medullaris to the coccyx to anchor the spinal cord.
What are denticulate ligmanets?
Also known as trabeculae and are projections of pia mater that anchor the spinal cord to the dura (projects through the arachnoid which is why it looks the way it does)
What are subarachnoid cisterns?
Dilated subarachnoid spaces located where pia mater is not present but dura and arachnoid mater are present..
What are arachnoid granulation/
Extensions of pia mater at the top of the cerebrum into dural sinus.
What is the function of arachnoid granulations?
They project into superior sagittal sinuses and provide an avenue for one-way CSF flow into venous blood (i.e they drain the CSF)
Does the dura mater get sensory nerve supply?
Only the periosteal layer does
What are the layers of the dura mater?
Periosteal layer (adheres to periosteum of the skull)
Meningeal layer divides cranial cavity into compartments
What does the periosteal layer of dura do?
Adheres to periosteum of the skull.
What are the important functions of the meningeal layer?
Forms dural reflections preventing excess movement of brain within cranial cavity.
The folds anchor the brain and prevent excess movement
The folds carry veins in what are called dural venous sinuses which drain CSF
What nerves carry sensory innervation to dura?
Vagus
Trigeminal
3 cervical nerves
What are the meningeal reflections that are important for formation of compartments in the brain?
Falx cerebri
tentorium cerebelli
Falx cerebelli
Diaphragm sellae
Where does the falx cerebri start?
At the crysta gali (cribiform plate) anteriorly and the tenrorium cerebelli posteriorly
What does the tentorium cerebelli divide the brain into?
Supratentorial and infratentorial cavities
What are the attachments of the tentorium cerebelli?
Anterior: Free border forms tentorial notch which attaches to the anterior clinoid process.
Posterior: Petrous part of temporal bone, occipital bone
Superior attachment: Falx cerebri
Inferior attachment: Falx cerebelli
What is the falx cerebelli?
Continuation of the falx cerebri which forms a membrane that goes between the 2 hemispheres of cerebellum.
What are the attachments of the falx cerebelli?
Anterior: Free border partially separating cerebellar hemispheres
Posterior Occipital bone
Superior: Tentorium cerebelli
Inferior: Posterior foramen magnum
What is the function of the diaphragm sellae?
Cover the sella turcica and forms the root of the pituitary fossa.
Allows passage of infundibulum
What are the attachments of the diaphragm sellae?
Anterior: Tuberculum sellae
Posterior: Dorsum sellae, posterior clinoid process.
Sinuses are easier to learn by looking at diagram on the slides.
All we really need to know is that they all drain into the internal jugular.
