Olfactory Nerve/Bulb

[AggieSean]

We're doing head & neck in gross anatomy right now. They have twice told us that the olfactory bulb is NOT part of the cranial nerve, and we should not label it as such on exams.

Is there any explanation for this? Why aren't the olfactory bulb/tract considered part of the first cranial nerve?

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[ZagDoc]

It's not a cranial nerve because it's part of the brain.

 

[ACSurgeon]

We're doing head & neck in gross anatomy right now. They have twice told us that the olfactory bulb is NOT part of the cranial nerve, and we should not label it as such on exams.

Is there any explanation for this? Why aren't the olfactory bulb/tract considered part of the first cranial nerve?

The first cranial nerver is the little nerves going through the cribiform plate to the bulb. The bulb is where CN1 synapses if you will. It's like saying why isn't the trigeminal nucleus considered to be part of CN5.

 

[TMP-SMX]

The bulb is the secondary sensory neuron of the olfactory pathway. The cranial nerve itself is within the cribriform plate and is the primary sensory neuron of the olfactory pathway. Get an injury to the cribriform plate and you tear all those tiny CNIs to pieces. Also at risk for recurrent infection and meningitis due to CSF leak until repaired but you'll find out about that next year.

 

[AggieSean]

Thanks for the replies. It just seems strange. c'est la vie.