What are some leading causes for raised ICP?
- Brain tumour
- Head injury
What does the Monro-Kellie hypothesis state?
The volume of the cranial cavity is constant
Brain tissue, blood and CSF are in dynamic equilibrium and an increase in one must lead to a decrease in another
Why can raised ICP compress the optic nerve?
Optic nerve is covered by meninges
What are the three meningeal layers which cover the optic nerves?
Which meningeal space is filled with CSF?
The dura mater is the ________ meningeal layer
The dura mater is the toughest meningeal layer
Where does the dura mater receive its sensory supply?
What are enclosed within the dura mater?
Dural venous sinuses
What is found within the subarachnoid space?
- Blood vessels
Which meningeal layer adheres directly to the brain?
What produces CSF?
What does the subarachnoid space surround?
- Spinal cord
How much CSF is produced daily?
Where can CSF be reabsorbed?
Dural venous sinuses via arachnoid granulations
At which vertebral level does the subarachnoid space terminate?
Where is the 3rd ventricle found within the cranial cavity?
Midline within diencephalon
Where are the left and right lateral ventricles found within the brain?
Left and right cerebral hemispheres
Which structure connects the 3rd and 4th ventricles?
Where can the 4th ventricle be found?
Between cerebellum and pons
Decribe the pathway of CSF from production to reabsorption
- Produced by choroid plexus in lateral ventricles
- Drains into 3rd ventricle
- Drains into cerebral aqueduct
- Drains into 4th ventricle
- Drains into subarachnoid space
- Reabsorbed via arachnoid granulations into dural venous sinuses
Which nerve palsy causes the eye to look down and out?
Which two septae formed from dura mater divide the cranial cavity?
- Falx cerebri (sagittal)
- Tentorium cerebelli (transverse)
Why is the trochlear nerve susceptible to damage?
It has the longest intracranial course
Palsy of the abducens nerve will lead to paralysis of which muscle?
What does someone look like with an abducens nerve palsy?
Medial deviation of eye (cannot move in horizontal plane)