Meninges and CSF Production Flashcards
What are the meninges?
Protective continuous coverings of the brain and spinal cord
What are the three meninges that protect the brain?
Dura mater, arachnoid mater and pia mater
What nerve gives sensory innervation to the dura mater?
CN V
What structure does the dura mater enclose?
The dural venous sinuses
What are the two layers of the dura mater?
Periosteal = attaches to bone
Meningeal = attaches to other meninges
Make the dura mater tough and thick
What is the function of the dural venous sinuses?
Drain deoxygenated blood from the brain
What does the arachnoid mater look like?
A spider’s web = contains arachnoid granulations
Where is the subarachnoid space located?
Between the arachnoid mater and the pia mater
What does the subarachnoid space contain?
Circulating CSF and blood vessels
What is special about the pia mater?
It completely adheres to the brain (including all of the sulci etc)
What does the CSF surround?
Completely surrounds the brain and spinal cord (both internally and externally)
At what level can the subarachnoid space be accessed via lumbar puncture?
At L3/4 level or L4/5 level
What level does the subarachnoid space end at?
S2 level
What plane are the third and fourth ventricles located in?
Both located in midline
Where do the right and left ventricles meet?
At the third ventricle
What does the cerebral aqueduct connect?
Flows down from third ventricle to connect is to the fourth ventricle
What is the largest of the dural venous sinuses?
The superior sagittal sinus
What produces CSF?
The choroid plexus = epithelium/modified pia located in the lateral and third ventricles
How does CSF flow through the ventricles?
Passes in the right and left ventricles , and then into the third ventricle before moving down the cerebral aqueduct to the fourth ventricle
Where does CSF go once it has left the fourth ventricle?
Most passes into the subarachnoid space, but some passes into central canal of the spinal cord
What reabsorbs the CSF into the dural venous sinuses?
Arachnoid granulations = out-pouches of arachnoid mater
What happens to CSF once it enters the dural venous sinuses?
Passes around body with deoxygenated blood for recycling
