Taste and smell disorders


Taste and smell disorders are complete or partial loss of either or both senses. Some individuals may experience distorted taste or smell, such as smelling odors that are not present or perceiving unusual scents or tastes.
Taste and smell disorders can be caused by many different factors including heredity, infection, exposure to toxins, and certain medications. Depending on the factors involved, these disorders can be either temporary or permanent.
Smell and taste belong to the chemical sensing system, called chemosensation. Individuals are able to taste and smell because specific nerves in the nose, mouth, and throat are stimulated when they come into contact with a stimulus, such as odors or food. Once these cells are stimulated, they transmit messages to the brain, where specific tastes or smells are identified.
Olfactory cells are the nerve cells involved with smell. They are located inside a small patch of tissue high in the nose and they connect directly to the brain. Odors stimulate the olfactory nerve cells.
Gustatory cells are the nerve cells involved with taste. These cells are grouped together in clusters inside the taste buds in the mouth (especially on the tongue) and throat. When individuals eat or drink, these surface cells are stimulated to send messages through nearby fibers to the brain where the specific tastes are identified.
The terms "flavor" and "taste" are often used synonymously, but they are actually two separate senses. Taste refers to sweet, sour, salty, and bitter. Flavor, on the other hand, involves taste and smell, as well as texture, color, and temperature. In fact, smell contributes to about 75% of flavor sensations. This is why individuals who have stuffy noses are often unable to taste their food.
Sense of taste and smell allow individuals to enjoy the aromas and flavors of foods and drinks. These senses also allow individuals to identify spoiled foods, which deters them from ingestion and prevents food poisoning. They can also warn individuals of dangers, such as fire, polluted air, and toxic chemicals.
More than 200,000 Americans visit physicians each year with complaints of taste and smell disorders, according to researchers. While many patients report a decrease in both smell and taste, about 80% of cases involve smell loss only. This is because the sense of smell contributes to 75% of flavor sensations.

Related Terms

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