Why Are Olfaction And Gustation Called Chemical Senses?


Table of Contents

There are five senses that we use to perceive the world around us. Sight, sound, touch, smell and taste are all ways in which our brains process the information they receive from stimuli outside of us. But what makes these two senses different? Olfaction is also called “the sense of smell,” while gustation is known as “the sense of taste.” These two senses have a lot in common with one another in that both involve detecting substances through chemical reactions.

Why Are Olfaction And Gustation Called Chemical Senses?

Did you know that smell and taste are not the only chemical senses? Olfaction and gustation are also known as the chemical senses. These two senses have a lot to do with what we eat, drink, or touch. This blog post will explore how these two senses help us make decisions.

Olfactory epithelium is located in our upper nasal cavity near the roof of our mouth. The olfactory nerve sends messages about smells to the brain which then interprets them for us (you can read more here). Gustation often goes along with tasting because it is where we detect tastes like sweet, sour, salty, bitter and umami (you can read more here). Chemical signals from food go through special sensory cells.

What is Olfaction?

Olfaction is the sense of smell. This blog post discusses what olfaction is, how it works and why it’s important. The human nose has about 350 million odor receptors that send information to the olfactory bulb in the brain. Oftentimes these receptors are stimulated by molecules that come from things like food, flowers or coffee beans.

When you smell something there is a process happening where your nose detects an odor molecule which then sends signals to your brain interpreting them as specific smells through synapses called glomeruli. These synapses tell your brain what you’re smelling so your brain can identify it and associate memories with it – whether good or bad!

What Is The Sense Of Olfaction?

What Is The Sense Of Olfaction? The sense of olfaction is a sensory process by which humans and other animals perceive odors or scents with their nose and mouth. The sensing molecules stimulate nerve cells in the nose called “olfactory receptor neurons.” These neurons send signals via nerves to specific regions in your brain, such as the amygdala, where emotional responses occur. In addition to being an important part of taste perception

Classes Of Olfactory Senses

The five classes of olfactory senses are fragrance, odor, stench, scent and aroma. All these different smells help us to identify what we like and dislike in our surroundings. One way we sense scents is through the nose which has two nostrils on each side of the face. The other three ways we sense scents is through inhalation (breathing), exhalation (blowing) and perspiration (sweating). Scent can also be sensed by animals such as dogs who have a much better sense of smell than humans do!

What Is The Olfactory Sensory System?

Think about the last time you had a good whiff of something delicious. The smells that make up an apple pie, for example, are cinnamon, applesauce and butter. Our sense of smell is made possible by our olfactory sensory system which detects these aromatic molecules in the air that we breathe. This system begins with our nose where scent particles connect to receptor cells inside tiny nasal hairs. These cells then send nerve signals to your brain’s olfactory bulb area which interprets them as different odors or fragrances.

What Is The Sense Of Gustation?

When the dissolved food molecules interact with your taste buds, it leads to the development of a sense of gustation. Receptors play the main role in the mediation of gustation by responding to the chemical stimulation taking place at the dorsum region of the tongue and in the areas of the pharynx, larynx, and epiglottis.

Classes Of Gustatory Senses

There are 5 major classes of gustatory senses discovered till now. These classes include:

Sweet, sour, salty, bitter, and umami.

Above are the main five classes of the gustatory sensory system and elaborated below on basis of the nature of the stimuli and source:

  • Sweet – generally implies nutrients that are high in energy.
  • Umami is the flavor of amino acids (e.g. meat broth or aged cheese)
  • Salty – enables diet modification for electrolyte balance.
  • Acidic flavors are often sour.
  • Bitter – enables the detection of a wide range of natural poisons.

What Is The Gustatory Sensory System?

The sensory detection of food on the tongue is known as taste perception or gustation. Taste is the feeling felt in the mouth when a substance chemically interacts with taste receptor cells found on taste buds or papillae, so we can say that the awareness of the chemical makeup and tastes of meals is thanks to our gustatory sensory system. If you “tasted it,” your gustatory sensory system was to blame (well, with some help from your olfactory system along with the help of some cranial nerves and gustatory cortex).

What Is The Functional Structure Of The Gustatory System?

Functional structures of the gustatory system:

  • Brain
  • Tongue

The gustatory sensory activities occur with the coordination of both the brain and the tongue on a neural and chemical level in the oral cavity.

Functioning of structures:

The process of tasting (gustation) begins in the mouth cavity and ends in the brain, where feelings such as sweet, sour, salty, bitter, and maybe umami (from glutamic acid salts such as monosodium glutamate), metallic (from iron salts), and chalky (from calcium salts) emerge. The olfactory (smell) and trigeminal (touch) systems in the nose and mouth collaborate with the gustatory (taste) system to add scent, texture, temperature, and spiciness to any tasted material, resulting in the overall sense of flavor. 

Many tastes are mediated by olfaction (for example, chocolate, coffee, strawberry, and peanut butter) since odorous volatiles emitted by food reach the smell receptors high in the nose through the retronasal pathway during chewing and swallowing.

Taste receptors in the oral cavity are located in taste buds that are innervated by branches of three cranial nerves: the facial (VII), glossopharyngeal (IX), and vagal (X). There has been significant progress in pinpointing the early events in flavor recognition. To identify flavor molecules, it appears that two distinct mechanisms have developed. It is commonly assumed that ion channels act as sensors for salty and sour tastes. H+ (sour) and Na+ (salty) ions are assumed to move into the cell through the channels. 

However, the molecular identification of the receptors and their precise processes are yet unknown for both of these taste attributes. G-protein-coupled receptors (GPCRs) appear to perform the most important roles in sweet, umami, and bitter sensations. These GPCRs bind taste molecules in a lock-and-key fashion.

What Are Some Deep-pressure Sensory Activities For The Sense Of Gustation?

As taste and smell go hand in hand the deep pressure sensory activities for gustation are done as Input to these systems can be provided by licking or smelling things such as crayons or toys. Chewing gives proprioceptive input as well. One may benefit from exploring smells through play with the following:

  • chewy toys
  • chewing gum
  • chewy or crunchy snacks
  • scented markers
  • essential oils

Deep Pressure Sensory Activities Recommended By Occupational Therapists:

  • Start with dry textures, move to semi-wet, and then wet food in a single session of food tasting.
  • Tasting sessions should be away from mealtime. Also include different tasting foods.
  • Try different levels of hot and cold temperature food in a controlled environment.
  • Brushing should be used as a deep pressure activity for the sensory idea.
  • Try different wet, dry, hard, and soft foods.
  • Smell different foods and essential oils and plants for olfactory sensations.

What Is A Gustatory Sensory Reflex?

Gustatory Sensory Reflex:

In a study, a method of accurately measuring the strength of stimulation of taste sensations was established using saliva electrolysis.

Mechanism of Gustatory Sensory Reflex:

Electrophysiological tests were carried out in anesthetized and decelerate hamsters to elucidate the brain regulatory mechanisms that serve the gustatory-salivary response. When taste stimuli were injected into the oral cavity, the efferent neural activity of postganglionic sympathetic and preganglionic parasympathetic fibers innervating the submandibular gland was observed. 

Primary gustatory afferent neural activity was also recorded from the chorda tympani (which innervates the anterior region of the tongue) and the glossopharyngeal nerve (innervating the posterior part of the tongue). The parasympathetic fibers had a modest rate of spontaneous discharge (approximately 0.3 Hz) and responded to taste stimulation of tone in an excitatory way. 

The level of parasympathetic activity was shown to be substantially linked with the amplitude of gustatory afferent responses from the chorda tympani rather than the glossopharyngeal nerve. Sympathetic fibers, on the other hand, had irregular burst discharges (1.5 burst/s), and the rate of burst discharges was enhanced in response to high concentrations of HCl (0.03 M) or NaCl (1 M) solutions. Differentiation trials show that gustatory information mostly influences parasympathetic activity via the chorda tympani, although sympathetic activity can be elicited by both the chorda tympani and the glossopharyngeal nerve.

Autism Spectrum Disorder And Gustation 

Autism Spectrum Disorder:

Autism spectrum disorder (ASD) is a complex developmental illness characterized by persistent difficulties in social interaction, spoken and nonverbal communication, and restricted/repetitive activities. The impact of ASD and the severity of symptoms vary from person to person. ASD patients frequently struggle with social, emotional, and communication abilities. They may repeat specific behaviors and refuse to modify their everyday routines. 

Many persons with ASD have unique ways of learning, paying attention, and responding to stimuli. ASD symptoms often appear in early childhood and persist throughout a person’s life.

Diagnosis of ASD can be challenging because there is no medical test, such as a blood test, to diagnose the problems. To make a diagnosis, doctors examine the child’s behavior and growth.

ASD can occasionally be recognized in children as early as 18 months. By the age of two, a professional diagnosis can be regarded as quite trustworthy. 1 Many youngsters, however, do not obtain a definite diagnosis until they are considerably older. Because of this delay, children with ASD may not receive the necessary early intervention.

ASD and Gustation:

Autism spectrum disorder patients frequently have selective or “picky” eating habits (ASD). These behaviors are frequently associated with abnormal sensory experiences in people with ASD, such as heightened response to food flavor and texture. However, little is known about the brain processes underlying ASD taste response. Food-related brain responses were assessed in 21 young adult and adolescent boys with ASD without intellectual impairment and 21 typically-developing (TD) controls in the current study. 

The Adolescent/Adult Sensory Profile, a clinical self-report tool, was used to assess taste reactivity. The hemodynamic reactions to sweet tastes and food images were evaluated using functional magnetic resonance imaging. Resting-state functional connectivity scans were also performed on the subjects. Self-reported taste reactivity and the reaction to sweet tastes within the insular cortex and numerous brain areas linked with gustatory perception and reward were found to be positively related in ASD participants. 

On tasting reactions in brain areas linked with ASD pathophysiology, including the bilateral anterior superior temporal sulcus, there was a substantial association between diagnostic group and taste reactivity. This taste response relationship was also detected in the resting-state functional connectivity between the anterior STS and the dorsal mid-insula.

These findings suggest that self-reported heightened taste reactivity in ASD is associated with increased brain responses to food-related stimuli and atypical functional connectivity of the primary gustatory cortex, which may predispose these people to maladaptive and unhealthy patterns of selective eating behavior.

Results Of Improper Gustation 

Improper gustation can lead to loss of taste and smell and perception of temperature of food and drinks, also defects in gustation can lead to loss of appetite and weight. These can also impact the psychological state leading to vertigo, nausea, and irritated mood.


The taste of the gustatory sensory system is an integral part of the sensory systems which give us sensory ideas of the taste and smell of food via chemical, mechanical, and electrical feedback of the brain and oral cavity with the help of neurotransmitters and nerves. Any deficits in the gustatory system can lead to loss of smell and taste.

If you like this article and would like to know more, please comment below.

Like and Share!

Share this post

One Comment

Leave a Reply

Your email address will not be published.


About CraftyThinking

CraftyThinking is a company that strives to inspire creativity in children by providing them with the opportunity to explore their creative side through art and crafts. We are about helping parents give their child an outlet where they can explore their creativity without worrying about the mess or time commitment!

Table of Contents

One Comment

Leave a Reply

Your email address will not be published.

Share this post

Activities in the Winter
Be the First to Know!

Get weekly updates about our latest crafts, educational resources and much more.

Frequently Asked Questions

  • Stress relief.
  • Confidence boost.
  • Increases empathy.
  • Improves quality of life for those with illness.
  • Enhances brain productivity. 
  • Lessens effect of serious health conditions.

When creating an arts and crafts project, children are able to develop their fine motor skills. … Art also allows for your child to expand their essential vocabulary. They’ll learn the names of different shapes, colors, and materials

  1. Crocheting.
  2. Kid Crafts.
  3. Knitting.
  4. Painting.
  5. Photography.
  6. Scrapbooking.
  7. Sewing.

Children can start making crafts as early as 9-10 months old. Learning the textures and coloring and painting and using playdough.

Art is described as an open-ended form of work; that expresses emotions, feelings, and vision. Craft denotes a form of work, involving the creation of physical objects, by the use of hands and brain. It is based on learned skills and technique.
  • Glass Pebble Magnets.
  • Children’s Headbands.
  • Palette Clock.
  • Decorative Champagne Flutes.
  • DIY Lace Bowls.
  • Flower Crowns.
  • Pallet Coasters.

CraftyThinking is actively working towards raising the quality of life for every child. We strive for all children, regardless of race, color, or circumstances to achieve their full potential. Our Mission is to make it possible using Arts and Crafts.

  • Arts & Crafts develops imaginations and encourages self-expression. Become creative and enhances your ability to innovate.
  • Boosts self-esteem and can instill a real sense of pride and achievement. Promotes feelings of relaxation and a sense of calm.
  • Art encourages creativity and imaginative thinking, two skills that are increasingly linked with long-term professional success. Art forces people to engage in out of the box thinking and can help them hone their creative problem-solving skills.
How To Draw

Get Your Free Drawing Book!

Sign up and get your free Farm Animal Book