Smelling

Smelling or olfaction is one of the five traditional senses. It refers to the ability to detect and identify the thousands of chemical species that are present in the air. Smelling occurs through the specialized sensory cells of the nasal cavity and is a key aspect of flavor perception.

Anatomy of the Olfactory System

The olfactory system includes several parts, including the nose, the olfactory bulb and the olfactory cortex. The nose is the main external part and contains the nostrils, which are lined with olfactory mucosa. This mucosa contains the olfactory receptors.

The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction. It sends olfactory information to the olfactory cortex, which is part of the cerebral cortex.

Olfactory Process

The process of smelling starts when molecules released by substances stimulate special nerve cells in the nose, known as olfactory cells. The olfactory cells are activated by the smell and send signals to the brain.

The brain then interprets the signals and identifies the smell. Smells are recognized based on past experiences and associations.

Disorders of Smell

There are several disorders related to the sense of smell, including anosmia, hyposmia, and parosmia. Anosmia is the inability to perceive odor or a lack of functioning olfaction. Hyposmia is a reduced ability to smell and to detect odors. Parosmia is a distortion of the sense of smell, in which something that normally smells pleasant now smells foul.

See Also

• Taste
• Sensory system
• Olfactory receptor

References

Smelling Resources
Latest articles Most recent articles Ongoing trials	Wikipedia