Olfactory

Question 1

What foramina does the olfactory nerve pass through?

Answer 1

Cribriform plate of the ethmoid bone

Question 2

What type of information does the olfactory nerve carry?

Answer 2

Special sensory

Question 3

What is the function of the olfactory nerve?

Answer 3

Olfaction (sense of smell)

Question 4

Describe the extracranial path of CNI?

Answer 4

Odour is detected by sensory cells in the nasal mucosa. This sensory information is then transmitted along the fine, unmyelinated axons of CNI which then enters the anterior cranial fossa

Question 5

Describe the intracranial path of CNI?

Answer 5

Axonal fibres communicate with neurones in the olfactory bulb, and axons from these neurones then form the olfactory tract to project into the olfactory cortices where information is processed

Question 6

What are some important facts to know about CNI?

Answer 6

It is the shortest CN / it is the only sensory CN which does not synapse at the thalamus before reaching the cortex

Question 7

How would CNI be tested?

Answer 7

Ask the patient to try and recognise a particular smell while covering the contralateral nostril