olfatoria

Olfactoria is a term used to denote things related to the sense of smell. In English, the standard adjective is olfactory, and olfactoria may appear in some Latin-derived or specialized texts to indicate odor-related aspects. The term is not a distinct anatomical structure, but a linguistic face used to reference smell-related systems and processes.

Biologically, olfaction begins with odorant molecules that reach the olfactory epithelium, a specialized sensory tissue located in the roof of the nasal cavity. The epithelium contains olfactory receptor neurons, each bearing receptors that detect specific odorants. Humans possess hundreds of olfactory receptor gene families, forming the largest gene family in the genome. Most olfactory receptors are G protein-coupled receptors, and their activation triggers intracellular signaling that generates an electrical signal.

The signals from olfactory receptor neurons converge in the olfactory bulb, where they synapse in structures called glomeruli. From there, information is relayed to primary olfactory cortex areas, including the piriform and entorhinal cortices, and then to other brain regions involved in emotion and memory. This pathway supports the perception of odors, the discrimination of flavors, and the triggering of memories and hedonic responses.

Variability in olfactory capability exists across species and individuals. Humans typically have hundreds of functioning olfactory receptor genes, with some pseudogenes, whereas many other mammals carry larger repertoires. Loss or impairment of smell, known as anosmia or hyposmia, can result from aging, injury, infections, or neurodegenerative conditions and is of clinical and research interest, particularly in relation to nutrition, safety, and quality of life.