Name (literally "concerning the olfactory nerve") for the perception of the smell (Olfactus = smell) over the nose as opposed to perceiving the taste over the tongue and the palate. The olfactory nerve (lat. Nervus olfactorius) is the first and shortest of the 12 cranial nerves. He is for the transmission of the odor impressions of the two-times stamp-sized olfactory mucosa (2 x 5 cm²) in the upper nasal cavity area with 20 million olfactory cells ( receptors ) responsible for the primary olfactory cortex in the cerebrum. The sense of smell is the most complex chemical sense. It depends on the individual amount of an odorant, from when it is perceived. This is called Perceptual threshold (Perceptual limit).
As part of a wine review (Tasting) or wine address (Description) is sometimes distinguished in "nasal" (also pronasal or orthonasal) when inhaling through the nose and "retronasal" when exhaling through the nasopharynx. At the olfactory perception are however two sensory Involved systems. This is in addition to the olfactory and the nasal-trigeminal system with a share of about 30%. odor and the taste interact and influence each other; an exact distinction is therefore not possible. See the other two senses below gustatory (tasting) and trigeminal (tactile = groping, touching).