week 1- protection of the brain Flashcards
the brain is protected by…
- cranium (skull)
- meninges
- blood brain barrier
- cerebrospinal fluid
what does the cranium do?
encloses brain to protect it from mechanical force
what are the meninges?
3 connective tissue membranes that cover external surface of brain and spinal cord
what is each membrane of the meninges called?
mater
what is the outermost membrane of the meninges called?
dura mater
what is the middle membrane of the meninges called?
arachnoid mater
what is the innermost membrane of the meninges called?
pia mater
what is outer dura mater?
strong, protective membrane that is double layered
what is the outer layer of the dura mater called?
periosteal layer
what does the outer periosteral layer attach to?
attaches directly to the inner surface of skull
what does the inner meningeal layer cover?
external surface of the brain
the two dural membranes are fused together but in areas where they seperate they enclose…
dural sinuses
what are dural sinuses?
channels that drain venous blood from the brain
what is dural folds(septa)?
tough, inward folds the help hold brain in position and prevent excessive movement
what is the arachanoid mater seperated from the dura mater with?
subdural space
what is the cavity found beneath the arachnoid membrane?
subarachnoid space
what does the subarachnoid space contain?
cerebrospinal fluid
what does cerebrospinal fluid do?
cushions brain further protecting from mechanical forces
what is pia mater?
very thin membrane that clings to surface of the brain
what does pia mater contain?
small blood vessels that supply oxygen and nutrients to brain and spinal cord
what does cerebrospinal fluid do?
- floats brain, reducing weight
- nourishes
- shock absorbing medium
how does CSF nourish the brain?
nourishes neural tissue and removes waste, functions as a diffusion medium between blood and neural tissue
where is CSF produced?
within the four ventricles of the brain by choroid plexus
what are the four ventricles of the brain interconnected with?
each other and central canal of spinal cord