The nervous system is the most important of all systems in the body, because it participates in coordinating the activities of all organs, shaping the mood of a person, and regulating his well-being. Without the nervous system, neither emotional, nor mental, nor physical activity is possible.
Scheme of the nervous system
Given the global role of the nervous system in the body, it is important to understand that it can be classified by structure and activity. For the overall development and a better understanding of the functioning of your body, it is important to know what parts of the system exist and what functions they perform.
In order to outline how the circuit of the nervous system looks, it is necessary to study the picture. After this, you can begin to consider each classification item in more detail.
The organs of the nervous system
Classification of the nervous system is, first of all, its physical structure. It consists of:
- brain;
- spinal cord;
- nerves
- ganglia and nerve endings.
The brain is the most important organ that regulates the activity of all organs, and in which stimuli (commands) are sent that are sent to the cells of internal organs and muscles.
The brain consists of several departments, each of which is “responsible” for certain functions.
Brain area | Main functions |
Medulla oblongata and bridge | Making decisions on triggering reactions that regulate the most important life functions: respiration, the work of the heart and blood vessels, digestion and wakefulness. |
Cerebellum | Automation of movements: maintaining balance, movement in space, arbitrary movements (for example, writing). |
Midbrain | Reaction to irritants, attention to what is happening. |
Diencephalon | Regulation of the endocrine system, "filtering" the signals entering the brain. |
Cortex | Smell, short-term memory, speech, thinking process, will and initiative. |
The brain actively exchanges signals with the spinal cord, which is located along the entire length of the spine, consisting of 31 fragments - the vertebra. The spine consists of four sections, each of which controls a certain "floor" of the body:
- cervical: neck, arms and diaphragm;
- chest: organs of the peritoneum and chest;
- lumbar: with legs;
- sacrococcygeal: the pelvis.
Thus, the signal of the nervous system from the brain enters the corresponding section of the spinal cord, and from there - to the necessary organs, cells, tissues. And the path from the spinal cord to specific nerve endings lies along the nerves, and, more precisely, along the axons of neurons in the form of short electrical impulses.
CNS and PNS
Knowing what organs the circuit of the nervous system consists of, it is possible to consider its primary division: the central and peripheral. The organs of the first are the brain and spinal cord. The peripheral nervous system includes motor and sensory nerves.
The activity of both systems is closely interconnected; they cannot exist autonomously. However, they have a number of distinct differences.
central nervous system
The central nervous system is considered the main part of the nervous system of people. She is responsible for the formation and implementation of reflexes, both simple and complex. The ability to these processes saves energy within the body. This has made a significant contribution to the development of the nervous system. From an evolutionary point of view on humans, it adapts to external factors, making life processes easier and faster.
The structure of the central nervous system is the brain and spinal cord. Both organs of this system are reliably protected from damage: the brain is located inside the skull, the spinal cord inside the spine. The brain is also protected by the blood-brain barrier, which protects the body from chemicals. In the event that any of the central nervous system organs is damaged, the quality of human life and his health, at least, will deteriorate, and in some cases a fatal outcome is possible.
Peripheral nervous system
In order to ensure the relationship of the central nervous system and organs, there is a peripheral part of the nervous system.
The peripheral nervous system includes nerve endings, neurons, nerves. The main function of the PNS is to control and control the muscles of the skeleton, regulate the work of all organs, and also maintain homeostasis. That is, after the brain sends a signal to the spinal cord, its corresponding section sends a synaptic signal through the axons of nerve cells to the desired organ. It can be both an exciting signal (for example, muscle contraction), and a relaxing one.
PNS provides a two-way communication between a person and his environment: he can not only perceive signals, but also respond to them with the help of movements, facial expressions.
Somatic nervous system
The somatic department of the nervous system is engaged in the conscious control of the body, unlike vegetation, which a person is not able to directly control. The somatic department is sometimes called an animal, because the activity of this system in animals and humans differs slightly.
The somatic department of the nervous system consists of the following organs:
- muscle
- leather;
- pharynx;
- larynx;
- tongue.
With the help of these tissues and organs, a person has the ability to control his body and feel tactile touches. The possibility of conscious control lies in the fact that a person can independently decide whether to go to him, to squat or not to move, but to decide what pulse or blood pressure he should have at the moment, a person cannot. Since these tasks are included in the competence of the vegetative system.
Vegetatics
Classification of people's nervous systems by their structure is not the only way to separate its departments. Of great importance is the autonomic nervous system, which directly controls the organs of all systems. A person cannot consciously control the activity of vegetatics, but information on how it works sometimes helps to correct well-being in vegetative disorders, for example, with a common disease - VVD (vegetative-vascular dystonia).
The activity of the autonomic nervous system is carried out at the expense of two departments-antagonists: sympathetic and parasympathetic. That is, when the sympathetic department is activated, the activity of the parasympathetic is automatically terminated.
Sympathetic Division
The sympathetic division of the autonomic nervous system is responsible for its activity. He launches bodily reactions, which are conventionally called "hit or run." That is, sympathy is launched in response to a situation requiring activity.
Physically, this manifests itself as follows:
- increase in muscle tone;
- increased heart rate;
- dilated pupils;
- increased blood pressure.
During the work of the sympathetic department of vegetation, the energy accumulated by the body is actively consumed. In order to restore energy reserves, it is important that the activity of the sympathetic and parasympathetic departments alternate.
Parasympathetic department
The opposite of the sympathetic division of the autonomic nervous system is the parasympathetic division. It is believed that he is responsible for the relaxation of the body, because when it is activated, the heartbeat slows down, the pupils expand, breathing becomes deeper and more measured.
But, in fact, one system begins to work only after parasympathetics is activated. And this system is the digestive tract.
In addition, such a classification of nervous systems according to the departments of vegetation suggests that parasympathetics is responsible for storing energy.
It is important to understand that the division of the nervous system into functions and departments is conditional, since the activity of this system, which is most important for humans, is carried out comprehensively, and all the categories described are closely interrelated. For example, it is known that a mental state has a direct effect on a physiological state. There are diseases called psychosomatic, which arise exclusively under the influence of psychogenic factors (stress, anxiety, phobia). Also, many dangerous somatic diseases, such as heart attack, stroke and, according to some, oncology, can occur under the influence of emotional stress.
Therefore, an understanding of what classifications of nervous systems exist, how they differ, and how they are interconnected, can not only positively affect their own erudition, but also prevent the development of neurological diseases and contribute to the elimination of psychogenic disorders.