====== Olfactory nerve ======

The [[olfactory]] [[nerve]] (Latin: Nervus olfactorius), known as the first [[cranial nerve]], or simply CN I, carries the sensory information for the sense of [[smell]]. Derived from the embryonic nasal placode, the olfactory nerve is capable of [[regeneration]]. The olfactory nerve is sensory in nature and originates on the [[olfactory mucosa]] in the anterosuperior [[nasal cavity]].

From the olfactory mucosa, the nerve travels down the olfactory tract until it reaches the olfactory bulb, where the fascicles of the olfactory nerve pass through foramina on the [[cribriform plate]], which resides on the roof of the nasal cavity. These fascicles are not visible on a cadaver brain because they are severed upon removal.

The sacrifice of the olfactory nerves is often required during a [[transbasal approach]] or [[subfrontal approach]].

{{::anteriorclinoidprocess.jpg|}}

AC: [[anterior clinoid process]]; ICA: [[internal carotid artery]]; LT: [[lamina terminalis]]; ON: [[optic nerve]]; OlN; [[olfactory nerve]]; SW: [[sphenoid wing]]; TS: [[tuberculum sellae]]; A1: A1 segment of the [[Anterior Cerebral Artery]]; A2: A2 segment of the [[Anterior Cerebral Artery]]; M1: M1 segment of the [[Middle Cerebral Artery]].

The [[pterional approach]] for [[anterior communicating artery aneurysm surgery]], has the following advantage: 

The [[subarachnoid space]] is widely opened and the [[brain hemorrhage]] can be removed as much as possible in the acute stages of [[SAH]]; damage of the [[olfactory nerve]] is minimized and bilateral parent arteries of the proximal side can be secured in an early stage of the procedure.