About what the nervous system , a person learns in his school years. Biology classes provide general information about the body as a whole and about individual organs in particular. As part of the school curriculum, children will learn that the normal functioning of the body depends on the state of the nervous system. If a failure occurs in it, the work of other organs is disrupted. There are various factors that affect this to one degree or another . The nervous system is characterized as one of the most important parts of the body. It determines the functional unity of the internal structures of man and the connection of the organism with the external environment. Let us consider in more detail what the nervous system is.
Structure
To understand what the nervous system is, it is necessary to study all its elements separately. The neuron acts as a structural unit. It is a cell having processes. From neurons, chains form. Speaking of what the nervous system is, it should also be said that it consists of two departments: central and peripheral. The first includes the spinal cord and brain, and the second - the nerves and nodes departing from them. Conventionally, the nervous system is divided into autonomic and somatic.
Cells
They are divided into 2 large groups: afferent and efferent. The activity of the nervous system begins with receptors. They perceive light, sound, smells. Efferent - motor - cells generate and direct impulses to certain organs. They consist of a body and a nucleus, numerous processes called dendrites. Fiber - axon is secreted in the nerve cell . Its length can be 1-1.5 mm. Axons provide impulse transmission. In the membranes of cells responsible for the perception of smell and taste, there are special compounds. They react to certain substances by changing their state.
Vegetative department
The activity of the nervous system provides the work of internal organs, glands, lymphatic and blood vessels. To a certain extent, it also determines the functioning of muscles. In the autonomic system, parasympathetic and sympathetic departments are distinguished. The latter provides the expansion of the pupil and small bronchi, increased pressure, increased heart rate, etc. The parasympathetic department is responsible for the functioning of the genitals, bladder, and rectum. From it come impulses that activate other nerves (oculomotor, glossopharyngeal, for example). The centers are located in the trunk of the brain and sacral part of the spinal cord.
Pathology
Diseases of the autonomic system can be caused by various factors. Quite often, disorders are the result of other pathologies, such as TBI, poisoning, infections. Failures in the autonomic system can be caused by a lack of vitamins, frequent stresses. Often, diseases are masked by other pathologies. For example, in case of violation of the functioning of the thoracic or cervical nodes of the trunk, pain in the sternum is observed, giving to the shoulder. Such symptoms are characteristic of heart diseases, so patients often confuse pathologies.
Spinal cord
Outwardly, it resembles a heavy. The length of this section in an adult is about 41-45 cm. There are two thickenings in the spinal cord: lumbar and cervical. They form the so-called innervation structures of the lower and upper extremities. The following departments are distinguished in the spinal cord : sacral, lumbar, thoracic, cervical. Throughout its length it is covered with soft, hard and arachnoid shells.
Brain
It is located in the cranium. The brain consists of the right and left hemispheres, trunk and cerebellum. It was found that its weight in men is more than in women. The brain begins its development in the embryonic period. The organ reaches a real size by about 20 years. Towards the end of life, brain weight decreases. It distinguishes departments:
- Finite.
- Intermediate.
- Middle.
- Rear.
- Oblong.
Hemisphere
They contain basal nuclei and the olfactory center. The outer shell of the hemispheres has a rather complex pattern. This is due to the presence of rollers and furrows. They form a kind of "convolutions". Each person has an individual figure. Nevertheless, there are several furrows that are the same for everyone. They allow you to select five lobes: frontal, parietal, occipital, temporal and hidden.
Unconditioned reflexes
The processes of the nervous system are a response to stimuli. Unconditioned reflexes were studied by such a prominent Russian scientist as I.P. Pavlov. These reactions are mainly focused on the self-preservation of the body. The main ones are food, indicative, defensive. Unconditioned reflexes are innate.
Classification
Unconditioned reflexes were investigated by Simonov. The scientist identified 3 classes of congenital reactions corresponding to the development of a specific area of the environment:
- Vital. They provide species and individual conservation of the body. Such reflexes include food, orientation, defensive, drinking, sleep regulation, etc. The criteria for such reactions are: physical death when the corresponding needs are not met, the implementation of the reaction without the participation of other individuals of the same species.
- Role-playing. These reflexes are realized only when interacting with other individuals of the same species. Such reactions form the basis for parental, territorial, etc. behavior. These reflexes are of particular importance for empathy, emotional resonance, the creation of a group hierarchy in which each individual has a specific role - a parent, partner, cub, alien or range owner, follower, leader, and so on.
- Self-development reactions. These reflexes are aimed at the development of spatio-temporal environments, they are facing the future. Such reactions include research behavior, imitation, resistance, etc.
Orienting reflex
It is expressed in involuntary sensory attention, accompanied by an increase in muscle tone. The reflex is caused by a new or unexpected stimulus. Scientists call this reaction "alarm", anxiety, surprise. Three phases of its development are distinguished:
- Termination of current activity, fixing posture. Simonov calls this general (preventive) inhibition. It occurs upon the appearance of any stimulus with an unknown signal.
- Transition to the "activation" reaction. At this stage, the body translates into reflex readiness for a likely encounter with an emergency. This is manifested in a general increase in muscle tone. In this phase, a multicomponent reaction takes place. It includes turning the head, the eye toward the stimulus.
- Fixation of the stimulus field to begin the differential analysis of signals and select a response.
Value
The orienting reflex is included in the structure of research behavior. This is especially evident in the new environment. Research activity can be focused on the development of novelty, and on the search for an object that can satisfy curiosity. In addition, it can provide an analysis of the significance of the stimulus. In such a situation, an increase in the sensitivity of analyzers is noted.
Mechanism
The implementation of the orienting reflex is a consequence of the dynamic interaction of many formations of nonspecific and specific elements of the central nervous system. The general activation phase, for example, is associated with the launch of the reticular formation and the beginning of generalized excitation of the cortex. In the analysis of the stimulus, cortical-limbic-thalamic integration is of primary importance. An important role in this is played by the hippocampus.
Conditioned reflexes
At the turn of the 19-20 centuries. Pavlov, for a long time studying the work of the digestive glands, revealed the following phenomenon in experimental animals. Increased secretion of gastric juice and saliva occurred regularly, not only with the direct ingestion of food in the digestive tract, but also while waiting for it to be received. At that time, the mechanism of this phenomenon was not known. Scientists attributed it to the "psychic arousal" of the glands. In subsequent studies, Pavlov attributed this reaction to conditioned (acquired) reflexes. They can arise and disappear during a person’s life. For the appearance of a conditioned reaction, it is necessary that the two stimuli coincide. One of them in any conditions provokes a natural response - an unconditioned reflex. The second, in view of its routine, does not provoke any reaction. It is defined as indifferent (indifferent). In order for a conditioned reflex to occur, the second stimulus must begin the action earlier than the unconditioned one for several seconds. Moreover, the biological significance of the first should be less.
Nervous System Protection
As you know, a variety of factors affect the body. The state of the nervous system affects the work of other organs. Even minor glitches at first glance can become the cause of serious illnesses. Moreover, they will not always be associated with the activity of the nervous system. In this regard, much attention should be paid to preventive measures. First of all, it is necessary to reduce the effect on the nervous system of irritating factors. It is known that constant stresses, experiences are one of the causes of cardiac pathologies. The treatment of these diseases includes not only medicines, but also physiotherapy, exercise therapy, etc. Of particular importance is the diet. The condition of all human systems and organs depends on proper nutrition. Food should contain enough vitamins. Experts recommend including vegetable products, herbs, vegetables and fruits in the diet.
Vitamin C
It has a beneficial effect on all body systems, including the nervous one. Due to vitamin C, energy production is provided at the cellular level. This compound is involved in the synthesis of ATP (adenosine triphosphoric acid). Vitamin C is considered one of the strongest antioxidants; it neutralizes the negative effects of free radicals by binding them. In addition, the substance is able to enhance the activity of other antioxidants. Among them are vitamin E and selenium.
Lecithin
It provides a normal course of processes in the nervous system. Lecithin is the main nutrient for cells. The content in the peripheral section is about 17%, in the brain - 30%. With insufficient intake of lecithin, nervous exhaustion occurs. A person becomes irritable, which often leads to nervous breakdowns. Lecithin is essential for all body cells. It is included in the B-vitamin group and contributes to energy production. In addition, lecithin is involved in the production of acetylcholine.
Music soothing the nervous system
As mentioned above, with diseases of the central nervous system, therapeutic measures can include not only taking medications. The therapeutic course is selected depending on the severity of the violations. Meanwhile, relaxation of the nervous system is often achieved without going to the doctor. A person can independently find ways to relieve irritation. For example, there are different melodies to calm the nervous system . As a rule, these are slow compositions, often without words. However, some people can be reassured by the march. When choosing ringtones, you should focus on your own preferences. It is only necessary to ensure that the music is not depressing. Today, a special relaxing genre has become quite popular. It combines classic, folk tunes. The main sign of relaxing music is a quiet monotony. It "envelops" the listener, creating a soft but strong "cocoon" that protects a person from external irritations. Relaxing music can be classical, but not symphonic. Usually it is played by one instrument: piano, guitar, violin, flute. It can also be a song with repeating recitative and simple words.
The sounds of nature are very popular - the rustling of leaves, the sound of rain, bird singing. In combination with the melody of several instruments, they take the person away from the daily hustle and bustle, the rhythm of the metropolis, and relieve nervous and muscle tension. When listening, thoughts are ordered, excitement is replaced by calm.