OP1 - intracranial pressure Flashcards
what are the meninges?
- dura mater (hard mother)
- arachnoid mater (spidery mother)
- pia mater (faithful mother) - closest to brain
= subarachnoid space in between arachnoid & pia mater
what nerve supplies dura mater?
CN V
what is in the subarachnoid space?
cerebrospinal fluid - CSF
what makes CSF? where released? where reabsorbed?
made by choroid plexus, goes through ventricles then released by cerebral aqueduct then reabsorbed into arachnoid granulations into dural venous sinuses
what is the monro kellie hypothesis about blood, brain, CSF? (just like general idea)
idea that these 3 are kept in equilibrium (balance)
what happens if increased cranial pressure?
increased pressure carried in CSF - since subarachnoid space & CSF in optic bundle means that optic nerve and central artery & vein also compressed so issues like swollen optic disc
what is papilloedema?
swollen optic disc as result of raised ICP
how are septae formed from dura mater?
dura mater has 2 layers - periosteal & meningeal layers = these seperate to make septae (folds)
what are important septae to know?
- faux cerebri (divides cranial cavity into left & right)
- tentorium cerebelli (tent over cerebellum)
- faux cerebri (divides cerebellum into right & left)
- diaphragm sellae (tent over potuitary)
what is tentorial notch?
hole where brain stem passing and where brain can herniate (move through) if high pressure
what is seen on eye with compression of CN III?
LR6 SO4 AO3 = means only lateral rectus & superioris oblique working so turned down & out
what is seen on eye if compression of CN IV?
LR6 SO4 AO3 = superior oblique not working so when abduct eye can’t look down
what is seen on eye if CN VI compression?
LR6 SO4 AO3 = lateral rectus not working so can’t look laterally
