neuro ques:cranial nerves

[cage92]

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does righ cranial nerves supply the left part(ex left occulomotor supply righ eye?😱😱😱 i am confused

 

[jakeislove]

Are you asking about accommodation?

 

[cage92]

Are you asking about accommodation?

nono i am asking in general like if the left cranial nerve supply a right part of the body?

 

[Old Style Nanny]

Cranial nerves don't cross. Except one motor and one sensory nerve.

Find out which ones they are yourself, and it will stay in your memory forever.

 

[cage92]

Cranial nerves don't cross. Except one motor and one sensory nerve.

Find out which ones they are yourself, and it will stay in your memory forever.

trochlear and facial?

 

[Old Style Nanny]

No do not confuse the crossing of the nerves (LMN) with the crossing of the (UMN) tracts. In general, those don't really matter clinically.

The only nerve that crosses is Trochlear (and Optic crosses partially and reaches both LGNs). So whenever there is a cranial nerve nuclei lesion, the lesion will be ipsilateral unless it is CN IV.

 

[cage92]

reallly thanks

 

[image187]

Also think in terms of UMN vs LMN.. An upper motor neuron lesion of CN XII would cause contralateral tongue deviation while a LMN lesion would cause deviation to the ipsilateral side. If you have a person with complete unilateral facial paralysis (eyelid and all) you know it is a peripheral facial nerve lesion (Bell palsy maybe due to lyme, HSV or most likely idiopathic) because the upper extent of the face is innervated by bilateral UMNs (an MCA stroke will spare the opposite orbicularis oculi).

 

[image187]

does righ cranial nerves supply the left part(ex left occulomotor supply righ eye?😱😱😱 i am confused

The left oculomotor nerve is not technically called this until the CN3 nucleus, which leaves ipsilateral to the side it innervates. The motor input to the nucleus is however supplied by a cortical motor neuron on the opposite side of the brain.

In short, the right brain controls the muscles in the left eye innervated by the left oculomotor nerve. This nerve also has other function (autonomics and stuff), and you're probably better off opening an anatomy book because it's probably a bit more clear there

 

[cage92]

The left oculomotor nerve is not technically called this until the CN3 nucleus, which leaves ipsilateral to the side it innervates. The motor input to the nucleus is however supplied by a cortical motor neuron on the opposite side of the brain.

In short, the right brain controls the muscles in the left eye innervated by the left oculomotor nerve. This nerve also has other function (autonomics and stuff), and you're probably better off opening an anatomy book because it's probably a bit more clear there

thanks so left facial nerve supply left side but its upper corticobulbar is right? But i read in kaplan that corticobulbar supply bilatrral so the righ face supplied bye lef and righ brain plz correct me

 

[image187]

thanks so left facial nerve supply left side but its upper corticobulbar is right? But i read in kaplan that corticobulbar supply bilatrral so the righ face supplied bye lef and righ brain plz correct me

The "facial nerve" is a peripheral structure originating from the CN VII nucleus, and innervates the ipsilateral facial muscles. The motor fibers in the facial nerve are lower motor neurons (like in other peripheral nerves), while the UMNs are neurons originating in the motor cortex And projecting onto the facial nucleus (corticobulbar tract). It just so happens that the motor fibers innervating the upper facial muscles receive bilateral cortical inputs to the facial nucleus on their side of the face, while the lower facial muscles only receive contralateral cortical input. So, of the entire half of the face is paralytic (or paretic), you know the lesion is most likely located in the peripheral facial nerve (after the facial nucleus)

 

[squeeze04]

It may be important for you to recall that V1 of CNV has bilateral innervation of the forehead. This is important from distinguishing a Bell's palsy from a stroke.

 

[cage92]

The "facial nerve" is a peripheral structure originating from the CN VII nucleus, and innervates the ipsilateral facial muscles. The motor fibers in the facial nerve are lower motor neurons (like in other peripheral nerves), while the UMNs are neurons originating in the motor cortex And projecting onto the facial nucleus (corticobulbar tract). It just so happens that the motor fibers innervating the upper facial muscles receive bilateral cortical inputs to the facial nucleus on their side of the face, while the lower facial muscles only receive contralateral cortical input. So, of the entire half of the face is paralytic (or paretic), you know the lesion is most likely located in the peripheral facial nerve (after the facial nucleus)

thhhankssss

 

[cage92]

It may be important for you to recall that V1 of CNV has bilateral innervation of the forehead. This is important from distinguishing a Bell's palsy from a stroke.

ok can you explain more? bcz v1 sensory not motor what is key between bells and stroke ?is the effect on facia?

 

[cage92]

what are those you are talking about ? i think those are low yield