The sense of smell , also known as smell , is the sense assigned to the perception of odorous stimuli .The olfactory stimuli are received by the nasal mucosa , and transmitted to the cells responsible for their transport to the brain, which transforms this stimulus into perception. The smell is therefore possible thanks to the interaction between the nose and the brain.
What is the sense of smell?
Among the five senses , the sense of smell is what allows the perception of odorous stimuli . The reception of odors is assigned to cells known as chemoreceptors. Located in a particular area of the nasal mucosa with yellowish pigmentation , known as the olfactory mucosa, these are cells that respond to the chemical characteristics of the odorous substances. These highly specialized neurons are equipped with a tuft of eyelashes and their bases extend into nerve fibers which, passing through the ethmoid bone – the bone that forms the roof of the nasal cavities – reach up to the olfactory bulbs; from here start other neurons that reach the brain, triggering the perception of odor. The nervous message of the odorous stimulus takes place in the olfactory mucosa. Here, the odorous molecules are made soluble, before fixing themselves on the cilia of the neurons. This phenomenon triggers the nervous message that reaches the brain through the olfactory bulbs .
The pathologies of the sense of smell can be of two types, quantitative and qualitative. Quantitative pathologies are given by hyposmia , or by the partial reduction of the sense of smell, and by anosmia , or the complete reduction of the sense of smell.
In the case of qualitative reductions in the sense of smell , however, we speak of parosmia, a disorder characterized by the alteration of the sense of smell. The underlying causes of these disorders can be different: rhinitis, sinusitis, neoplasms, lesions of the mucosa of various origins (viral, traumatic or inflammatory). The sense of smell inevitably also affects the sense of taste.
What is the sense of smell for?
Among the five senses, the sense of smell is the sense that allows the perception of odors .