The Nose!

Everybody nose that only about 5% of the cerbral cortex is devoted to the sense of smell. (Pardon the pun!) Pheromones are odors used for communication by animals.

The receptors for smell are located in the epithelium, which is a thin membrane in the top of the nasal cavity. The actual receptor cells, called olfactory cells, are stimulated by the gases that are dissolved in the fluid of the membrane. This means that in order for something to be smelled, it must be dissolvable in water.

The trigeminal sense is a second chemoreceptor system in the nose that is responsive to certain food flavors. It is responsible for the taste of some foods and of cigarettes.

Anosmia is the inablity to detect smell.