Term (literally translated "concerning the olfactory nerve") for the perception of smell (olfactus) via the receptors in the nose in contrast to the perception of taste via the tongue and palate. The olfactory nerve (lat. nervus olfactorius) is the first and shortest of the 12 cranial nerves. It is responsible for the transmission of olfactory impressions from the olfactory mucosa (2 x 5 cm²), which is twice the size of a postage stamp in humans, in the upper nasal cavity area with 20 million olfactory cells (receptors) to 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 odourant from which point it is perceived and can be interpreted. This is called the perception threshold (perception limit).
In the context of a wine evaluation (tasting) or wine address (description), a distinction is sometimes made between "nasal" (also pronasal or orthonasal) when inhaling via the nose and "retronasal" when exhaling via the nasopharynx. However, two sensory systems are involved in olfactory perception. In addition to the olfactory system, the nasal-trigeminal system also has a share of about 30%. Smell and taste interact and influence each other, however; an exact distinction is therefore not possible. See the other two senses under gustatory (tasting) and trigeminal (tactile = touching). See on the complex of topics also under aroma and aroma substances.
Graphic: From Chabacano - from Brain, mouth anatomy,
by Patrick J. Lynch, medical illustrator, CC BY-SA 2.5, Link
