Taste

Taste, or gustation, is the sensory system that detects dissolved chemical compounds in the mouth. It primarily refers to five basic tastes and contributes to flavor, although flavor also depends on smell, texture, temperature, and context.

Taste buds, the sensory organs of gustation, are located in taste papillae on the tongue and other oral surfaces. Each bud contains taste receptor cells with microvilli that reach a taste pore, forming connections with sensory neurons.

The five basic tastes are sweet, sour, salty, bitter, and umami. Some researchers propose a sixth taste, such as fat (oleogustus), but this remains debated. Sweet and umami are typically detected by G protein–coupled receptors; salt and sour through ion channels; bitter by diverse receptors.

Taste signals travel via cranial nerves VII, IX, and X to the nucleus of the solitary tract, then to the thalamus and primary gustatory cortex in the insula and frontal operculum. Perception of flavor also depends on smell and oral texture.

Genetics influence taste sensitivity, with variants in bitter receptors; age, health, medications, smoking, and nutrition can alter taste. Cultural exposure and eating experience shape preferences and perceived intensity.

Clinical relevance: disorders include ageusia (loss of taste), hypogeusia (reduced taste), and dysgeusia (distorted taste). Taste tests aid diagnosis and guide management of underlying conditions.