anatomy - meninges + ICP

Question 1

where does the sensory supply of the dura mater come from?

Answer 1

CN V

dura mater = hard, encloses dural venous sinuses

Question 2

list the layers of the meninges

Answer 2

dura mater
arachnoid mater
subarachnoid space - circulating CSF + vessels
pia mater - adheres to brain

Question 3

what vertebral layer would a lumbar puncture be carried out? why there?

Answer 3

L3-L5 - spinal cord ends at L2 so avoids any damage

accessing CSF

Question 4

what vertebral layer does the subarachnoid space end?

Answer 4

ends inferiorly at vertebral level S2

Question 5

circulation of CSF

Answer 5

secreted by choroid plexus (lateral + 3rd v)
lateral to 3rd midline adding CSF
into 4th via cerebral aqueduct
then mainly into subarachnoid space but some passes into central canal

Question 6

how can raised intracranial pressure cause eye pathology?

Answer 6

raised ICP will be transmitted along the subarachnoid space in the optice nerve sheath

Question 7

effect of raised ICP on optic nerve

Answer 7

will compress optic nerve + central artery + vein of retina

can lead to bulging or swollen optic discs = papilloedema

Question 8

visual symptoms of a compressed optic nerve

Answer 8

transiet visua; obscurations - graying-out of vision
transient flickering
blurring of vision
constriction of visual field
decreased colour perception

Question 9

how can raised ICP compress/stretch the oculomotor nerve?

Answer 9

if medial temporal lobe herniates through tentorial notch

Question 10

tentorium cerebelli

Answer 10

an invagination of the meningeal layer of the dura mater that separates the occipital + temporal lobes