90+ scorers, ur opinions on the entrances/exists of Cranial Nvs on base of skull

[Knicks]

Should be worried about memorizing these cranial fossae regarding the cranial nerves? This relatively simple task has always seemed annoying for me.

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[45408]

I think it's pretty worth your while. If you know that someone can't shrug their right shoulder after a trauma, and the question asks what other deficits to expect, it's good to know that the vagus and glossopharyngeal might also have been crushed.

I think you should know where all the cranial nerves originate and how they get to their end organ. And that the middle meningeal artery comes through f. spinosum and up the temporal bone and tends to be the cause of epidural hematomas.

 

[Blesbok]

There are only like 6 important ones, it shouldn't take that long to memorize.

 

[lord_jeebus]

Yes, this is "high yield" in my opinion

 

[mudphudwannabe]

I had a hard time with this too, but it is important. Don't waste time agonizing over it, though - just pick it up and look at it when you have a spare moment here and there, and if it doesn't seem solid, make sure you go through it at least once in the last day or two before the exam.

 

[Jbienven]

It's not that hard to learn, pretty much gimme questions if you know them. So why not?

Not to mention you probably could have learned 75% in the time it took to ask / worry about knowing it.

Just my 2 cents.

 

[Knicks]

^^ Excellent point.


Thanx for the input everyone.

 

[2cr8tive]

did u mean III and IV from midbrain, V,VI,VII,VIII from pons and IX, X, XII from medula (remembering the XI nerve is not really a cranial nerve)? is that what you cant memorize? or am i missing something?

 

[mudphudwannabe]

You need to know where the nerves exit through the skull.

 

[2cr8tive]

lol i see u mean the foramen
there are a couple of useful hints in first aid. makes it easier to memorize

 

[obiwan]

did u mean III and IV from midbrain, V,VI,VII,VIII from pons and IX, X, XII from medula (remembering the XI nerve is not really a cranial nerve)? is that what you cant memorize? or am i missing something?

is VIII from medulla or pons? i think in HY neuro, they show nuclei in both medulla and pons. Also, is lower face the only thing that does not receive bilateral innervation?

 

[UCLAstudent]

I agree --- definitely worth knowing where things exit the skull.

 

[dig003]

is VIII from medulla or pons? i think in HY neuro, they show nuclei in both medulla and pons. Also, is lower face the only thing that does not receive bilateral innervation?

The fibers of CN VIII enter the brain stem at the pontomedullary juntion (near the cerebellopontine angle) and synapse on either the ipsilateral cochlear nucleus for hearing or ipsilateral vestibular nuclei (2 on each side) for the maintenance of balance (i.e knowing where you are in space using angular/linear acceleration of the head)

The cochlear nucleus is located in the caudal pons (near the CNVIII entrance at the pontomedullary junction) while the vestibular nuclei extend down into the upper medulla... so if you see a section of the upper/rostral medulla you will see the vestibular nuclei of VIII on the far dorsal side but not the cochlear nuclei of VIII. Hope that helps...

Oh yeah the lower division of the facial nucleus is the only motor CN nucleus that does not receive bilateral input (it's input is from the contralateral UMNs/corticobulbar tract) but the sensory nuclei all receive ipsilateral input and project to the contralateral cortex. Please lemme know if any of this is wrong....

 

[78222]

There aren't that many, and as annoying as it is to memorize this sort of thing, I think it's necesarry for a good score.