Organs of Olfaction

Smell is one of the five basic senses that allow us to perceive the world around us. The sense of smell allows us to detect and recognize the various odors that surround us. The human olfactory organs are located in the nasal cavity and consist of the olfactory membrane, olfactory cells and chemoreceptors.

The olfactory membrane is located in the upper part of the nasal cavity and consists of three layers of cells: structural, olfactory and basal. Olfactory cells are nerve cells that sense chemical stimuli in the form of vapor. Chemoreceptors are located in the yellow mucous membrane and can detect seven basic odors: camphorous, musky, floral, minty, ethereal, acrid and putrefactive.

To excite the olfactory cells, the substances must be volatile and water soluble enough to dissolve in the mucus and reach the olfactory cells. Olfactory receptors become tired: after prolonged perception of the same substance, they stop emitting nerve impulses to this substance, but continue to remain sensitive to all other odors.

Chemoreceptors transmit nerve impulses to the olfactory bulb, and it transmits to the olfactory centers of the cerebral cortex, where sensations are evaluated and deciphered. The olfactory cells are stimulated only when air flows upward into the back of the nasal cavity.

In addition, the yellow mucosa contains Bowman's mucous glands, which secrete a fluid that keeps the olfactory epithelium moist and clean.

The sense of smell in humans is primitive compared to the same organs in some animals. For example, dogs and cats have a much more subtle sense of smell than humans. In insects, the sense of smell is very sensitive, as it is the means they use to find food, find individuals of the opposite sex, and detect other living things. Some insects, such as moths and moths, have the greatest olfactory sensitivity: males of these insects detect the scent of females at a distance of more than 1.5 km.

Overall, the sense of smell plays an important role in our lives, allowing us to detect and recognize the different smells that surround us. They help us navigate our environment, determine the safety and quality of food, and detect aromas that evoke positive emotions and associations in us. Despite the fact that the human olfactory organs are not as developed as those of some animals, they are still an important part of our physiology, and without them our lives would be much poorer and less rich in impressions.