From the perspective of psychology, called the eyes, ears or nose "senses" is not quite correct.Feelings - a concept referring to the emotional sphere, and the mental process provided by these bodies is called feeling.The scientific name of the senses - parsers, because they allow the brain to analyze their environment and internal environment.

structure analyzer



Each analyzer consists of three divisions.

First Division - peripheral perceiving stimuli and transforming it into excitement.It peripheral parts of the analyzers in the home called "the senses."Direct transformation of external stimuli in the excitation occurs in specific cells - receptors, which are a major part of the peripheral.

Second Division - nerve fibers that transmit the excitement of the peripheral to the central nervous system.Such fibers are called afferent, centripet
al or sensitive.

From receptor Department of afferent fibers excitation is transferred to the corresponding area of ​​the cerebral cortex - cortical analyzer department, where there is a feeling.

often talk about the "five senses" (ie, sensations), peculiar man.In fact, a person senses more.Together with sight, hearing, smell, touch and taste sensation of these include a sense of balance and proprioceptive sensations that signal muscle contraction and relaxation, and pain.The first five analyzers were "a special status" because it supplied them feeling increasingly aware.Pain has a special place becauseThere is no separate body, which would be located such receptors.

analyzers role in the life of a creature is not the same.For example, people can easily tolerate the loss of sense of smell (each such case, during a cold) can come to terms with the disappearance of the sense of taste, but the loss of vision, hearing or feeling of balance turns in heavy disabled person.For a dog, on the contrary, the loss of smell is much heavier than the loss of vision.

receptors



structure and function of afferent fibers and cortical analyzers department at all similar, the specificity is in the structure and type of peripheral receptors.

receptors are divided by location on exteroreceptors disposed on the body surface, and interoreceptors inside the body.But the main principle of the classification of receptors - those impacts that they can be transformed into excitement.

chemoreceptors respond to the composition of chemical substances, such for example, olfactory and taste receptors.Mechanoreceptors react to pressure, touch, oscillation of air or liquid medium and other mechanical stress, they are "responsible" for the hearing, proprioceptive sensation, supply information on increasing and decreasing blood pressure and other changes in the internal environment.The photoreceptors react to light, they are located on the retina.Thermoreceptors signals a change in ambient temperature.

occupy a special place nociceptors - receptors responsible for the pain.In fact, it's the same chemoreceptors, mechanoreceptors and thermoreceptors, but they work only at very high intensity stimulus.Causes of pain and overly hot water (thermoreceptors), and too much hot spices in food (chemoreceptors) and too loud (mechanoreceptors).Yet these cells have a feature that distinguishes them from other receptors - polymodality.This means that the same receptors are excited by different effects that threaten the body.