The senses are responsible for our ability to interpret the environment, that is, to capture different stimuli around us. Without the senses we would not be able to perceive the variations of the environment and, consequently, to produce an adequate action in the face of danger. Traditionally, we have accepted that human beings have five main senses: sight, smell, taste, hearing and touch.
Imagine, for example, that there is a gas leak in your kitchen. The gases that make up cooking gas have no smell, but substances are added so that we are able to detect a leak. A person incapable of perceiving odors would not know how to identify the danger and could, for example, cause an explosion when lighting a fire.
→ sensory receptors
This ability to perceive the environment is possible thanks to the presence of sensory receptors, which capture stimuli and transform them into nerve impulses. These are interpreted in specific centers of the nervous system, which will produce adequate responses to that stimulus. These receptors are located in the so-called sense organs.
Sensory receptors can be classified based on the stimulus they are able to perceive. The main receivers are:
Chemoreceptors - They are receptors capable of perceiving chemical stimuli;
Photoreceptors - They are receptors capable of perceiving light stimuli;
Mechanoreceptors - They are receptors capable of perceiving mechanical stimuli, such as pressure and touch;
Phonoreceptors - They are receivers capable of perceiving sound stimuli. Many authors consider these receptors as mechanoreceptors.
→ the senses
Eyesight: Sense related to light gathering and imaging. Sensory receptors for this sense are located in the eyes, more precisely in the retina. The sensory receptors in vision, which are photoreceptors, are called cones and rods.
Hearing: Sense related to the capture and perception of sound waves. Sensory receptors in this sense are located in a region of the ear called the cochlea. These receptors are of the mechanoreceptor type.
Smell: Sense responsible for capturing the odor of chemical particles present in the air. Sensory receptors related to this sense are located in the olfactory epithelium, located at the top of the nasal cavity, and are chemoreceptors.
taste: Sense related to the perception of food flavors. The receptors responsible for this sense are present in structures called taste buds, distributed throughout the tongue, palate, pharynx, epiglottis and larynx. Sensory receptors, like smell receptors, are chemoreceptors. Taste and smell work together in the perception of flavors.
tact: Sense responsible for allowing the perception of textures, pain, temperature and pressure. Receptors related to this sense are of the mechanoreceptor type and are present throughout the skin, mucous membranes and some viscera. There are different receptors, each related to a different type of tactile stimulus.
In this space you will learn more about each sense and how stimuli are perceived by each organ. Good reading!
By Ma. Vanessa dos Santos
