Smell is one of the five senses, with which smells are perceived and distinguished; which resides in the nose, and where the chemoreceptors that respond to chemicals in the air are found.
In nature, many functions such as attracting the female for reproduction, getting food, fleeing from the enemy are performed thanks to chemoreceptors. For example, in insects, chemoreceptors related to smell are located on their antennae and use them to get food.
Most male mammals "mark" their territory with urine to warn other males of their presence and, in general, when they do not know the way they mark it in the same way so as not to get lost (very common in dogs). Phenomena like these show us the importance of smell in animals.
The sense of smell resides in the upper portion of the nostrils, exactly in a yellowish membrane called the yellow pituitary or olfactory region. In it are the olfactory receptors, which are located in special epithelial cells, these extend with nerve fibers corresponding to the first cranial or olfactory nerve, and through the olfactory band, they reach the cerebral cortex.
In order for the pituitary to be impressed, the substances must be in the gaseous state. On the other hand, the olfactory mucosa must be moist for odorous sensations to take place.
When we breathe, volatile chemicals pass through the nasal cavity. There they come into contact with the olfactory mucosa, and stimulate the olfactory nerve endings whose function is to carry this message to the brain, which will translate the message into an odorous substance.
It is important to highlight the adaptability of smell to continuous stimulation. When we are continuously exposed to a certain smell, the olfactory sensation progressively diminishes, until it disappears: the olfactory cells are adapted. However, if other smells reach them, they will pick them up without any problem.
The human being can perceive more than 5,000 different smells. Research indicates the existence of seven primary odors: camphor, musk, flowers, peppermint, ether (dry cleaning fluids, for example), pungent (vinegary), and rotten.
Smell is also referred to the ability, quality or insight to discover or perceive something. For example: José has a great nose for business in sales.
