The olfactory portion of the nose is exclusively involved in the sensation of smell. The olfactory portion of the nose consists of: the olfactory epithelium, olfactory nerves and olfactory bulb. The olfactory epithelium is a soft patch on the roof of the nasal cavity. This epithelium has several olfactory hair cells connected to the olfactory bulb. The olfactory bulb extends towards the olfactory nerves. The olfactory nerves convey signal to the olfactory centres of the brain where the smell/odour is identified.