Flashcards in Meninges and spinal cord Deck (19):
Name the meninges
Dura mater, arachnoid mater, pia mater
Describe the dura mater in the skull
2 layers, endosteal is similar to the periosteum, inner meningeal layer
Usually fused but sometimes separate to form sinuses for venous blood drainage
Describe the dura mater in the spinal cord
Continuous with meningeal dura, separated from the periosteum of spinal vertebrae by loose fatty CT that contains the internal vertebral venous plexus
What is the falx cerebri?
Fold of dura in the mid saggital plane between the 2 hemispheres
What is the tentorum cerebelli?
Dura that covers the cerebellum and supports occipital lobes. Attached to petrous temporal bone and occipital bone
What is the falx cerebelli?
Small vertical fold of dura between two cerebellum hemispheres (attaches to occipital bone and tentorum cerebelli)
What happens to the dura when cranial nerves leave the skull?
Blends with epineurium
What is the blood supply to the dura?
Middle meningeal artery lies between meningeal and endosteal layers of dura
What is in the subarachnoid space?
CSF and cerebral vessels, cranial nerves also pass through
What are arachnoid granulations?
Protrusions of arachnoid mater that provide a route for CSF to return to blood, found in venous sinuses (esp. superior sagittal sinus)
Describe the pia mater
Closely invests in the brain and accompanies cerebral arteries into the substance of the brain
What is a cistern? Name 3 examples
An enlargement of subarachnoid space
E.g. interpenduncular, cerbromedullary and pontine
What happens if there is a rupture of an aneurysm of the circle of willis?
Thunderclap headache at back of head
What happens if there is a tearing of the veins in the brain?
Occurs in very young and very old due to smaller brains
Slower and self limiting as bleeds into venous sinuses
What happens if there is a minor blow to the head at the pterion?
Middle meningeal vessel damage
Where is a lumbar puncture taken and why?
Subarachnoid space (containing CSF) extends to S2 whereas spinal cord terminates at L1 so L2-L4 is safe
What is the ligamentum denticulatum?
Attaches pia mater to dura and arachnoid mater so the spinal cord is suspended in the dural sheath
What is the blood supply of the spinal cord?
Anterior spinal artery and 2 posterior spinal arteries (from vertebral arteries)
Reinforced by segmental arteries from intervertebral foramina
All that enter spinal medulla are end arteries