orthonasalis
Orthonasal, also spelled orthonasalis, is a term used in anatomy and sensory science to describe olfactory perception that occurs when odorants enter the nasal cavity through the external nares (the nostrils). It contrasts with retronasal olfaction, in which volatile compounds reach the olfactory receptors from the oropharynx during eating or drinking. The orthonasalis route is the primary pathway for most environmental odors, while retronasal input is closely linked to flavor perception.
Anatomy and physiology follow a common olfactory pathway. Odorants inhaled through the nostrils dissolve in mucus
In research and clinical practice, orthonasalis olfaction is often assessed separately from retronasal olfaction. Olfactometry and
Clinically, conditions such as nasal obstruction, chronic rhinosinusitis, or head trauma can impair orthonasalis olfaction. Understanding