Olfactory Nerve
Description[edit | edit source]
The Olfactory Nerve is also known as the first cranial nerve. It is a pure sensory nerve that functions for the sense of smell.
Root[edit | edit source]
The olfactory nerve terminates at the olfactory bulb, located just above the ethmoid bone and below the frontal lobe. The olfactory bulb acts as a relay center for the transmission of the impulses from the olfactory nerve to the olfactory tract and then to the cerebral cortex.
Branches[edit | edit source]
The olfactory nerve divides into two branches. These are:
Lateral olfactory nerves- located in the superior nasal concha
Medial olfactory nerves- located along the nasal septum
Pathway[edit | edit source]
Function[edit | edit source]
Sensory[edit | edit source]
Clinical relevance[edit | edit source]
Anosmia
Hypoosmia
Hyperosmia
Dysosmia
Assessment[edit | edit source]
Assessment of the olfactory nerve is readily done either at bedside or in the clinic. Testing of the integrity of the olfactory nerve involves either pinching or blocking of one nostril while the patient is blindfolded or with the eyes closed, then have the patient smell aromatic substances such as coffee, vanilla, cinnamon, etc. Avoid using substances with strong or noxious smell such as alcohol or ammonia. Have the patient identify the substance based on its aroma. Then repeat the same procedure on the other nostril. This is done to compare the sense of smell on both sides.
