Central part of the brain. Parts of the brain and their functions: structure, features and description

The brain is the most important organ of the central nervous system, from a physiological point of view, consisting of many nerve cells and shoots. The organ is a functional regulator responsible for performing various processes that occur in the human body. On this moment The study of structure and functions continues, but even today it cannot be said that the organ has been studied at least half. The structural diagram is the most complex when compared with other organs of the human body.

The brain consists of gray matter, which is a huge number of neurons. It is covered with three different shells. Weight varies from 1200 to 1400 g (for small child- approximately 300-400 g). Contrary to popular belief, the size and weight of an organ do not in any way affect the intellectual abilities of an individual.

Intellectual abilities, erudition, efficiency - all this is ensured by high-quality saturation of brain vessels useful microelements and oxygen, which the organ receives exclusively with the help blood vessels.

All parts of the brain must work as harmoniously as possible and without disturbances, because the quality of this work will determine a person’s standard of living. In this area, increased attention has been paid to cells that transmit and form impulses.

You can briefly talk about the following important departments:

• Oblong. Regulates metabolism, conducts analysis nerve impulses, processes information received from the eyes, ears, nose and other senses. This section contains the central mechanisms responsible for the formation of hunger and thirst. Separately, it is worth noting the coordination of movements, which is also in the area of ​​​​responsibility of the medulla oblongata.
• Front. This department includes two hemispheres with the gray matter of the cortex. This zone is responsible for many important functions: the highest mental activity, the formation of reflexes to stimuli, a person’s demonstration of elementary emotions and the creation of characteristic emotional reactions, concentration of attention, activity in the field of cognition and thinking. It is also believed that pleasure centers are located here.
• Average. It consists of the cerebral hemispheres and the diencephalon. The department is responsible for physical activity eyeballs, the formation of facial expressions on a person’s face.
• Cerebellum. Acts as a connecting part between the pons and the hindbrain and performs many important functions, which will be discussed below.
• Bridge. A large section of the brain that includes the centers of vision and hearing. It performs a huge number of functions: adjusting the curvature of the eye lens, pupil sizes in different conditions, maintaining balance and stability of the body in space, forming reflexes when exposed to irritants to protect the body (coughing, vomiting, sneezing, etc.), control of the heartbeat, work cardiovascular systems s, assistance in the functioning of others internal organs.
• Ventricles (4 pieces in total). Filled cerebrospinal fluid, protect the most important organs of the central nervous system, create cerebrospinal fluid, stabilize the internal microclimate of the central nervous system, perform filtering functions, and control the circulation of cerebrospinal fluid.
• Wernicke's and Broca's centers (responsible for human speech abilities - speech recognition, understanding, reproduction, etc.).
• Brain stem. A prominent section, which is a fairly long formation that continues the spinal cord.

All departments as a whole are also responsible for biorhythms - this is one of the types of spontaneous background electrical activity. All lobes and sections of the organ can be examined in detail using a frontal section.

It is a common belief that we use 10 percent of our brain capacity. This is a misconception, because those cells that do not participate in functional activity simply die. Therefore, we use the brain 100%.

Finite brain

Part telencephalon It is customary to include hemispheres with a unique structure, a huge number of convolutions and grooves. Taking into account the asymmetry of the brain, each hemisphere contains a nucleus, a mantle, and an olfactory brain.

Hemispheres are presented in the form multifunctional system with many levels, which includes a vault and corpus callosum, connecting the hemispheres to each other. The levels of this system are: cortex, subcortex, frontal, occipital, parietal lobes. The frontal is necessary to ensure normal motor activity human limbs.

Diencephalon

The specific structure of the brain affects the structure of its main sections. For example, the diencephalon also consists of two main parts: ventral and dorsal. The dorsal section includes the epithalamus, thalamus, metathalamus, and the ventral section includes the hypothalamus. In the structure of the intermediate zone, it is customary to distinguish between the pineal gland and the epithalamus, which regulate the body’s adaptation to changes in biological rhythm.

The thalamus is one of the most important parts because it is necessary for humans to process and regulate various external stimuli and the ability to adapt to changing conditions environment. The main purpose is to collect and analyze various sensory perceptions (with the exception of smell), transmitting corresponding impulses to large hemispheres.

Considering the structure and function of the brain, it is worth noting the hypothalamus. This is a special separate subcortical center, completely focused on working with various vegetative functions human body. The influence of the department on internal organs and systems is carried out with the help of the central nervous system and glands internal secretion. The hypothalamus also performs the following characteristic functions:

• creation and support of sleep and wakefulness patterns in everyday life.
• thermoregulation (support normal temperature body);
• regulation of heart rate, breathing, blood pressure;
• control of the sweat glands;
• regulation of intestinal motility.

The hypothalamus also provides a person’s initial response to stress and is responsible for sexual behavior, so it can be described as one of the most important departments. When working together with the pituitary gland, the hypothalamus has a stimulating effect on the formation of hormones that help us adapt the body to a stressful situation. Closely related to work endocrine system.

The pituitary gland is relatively small in size (about the size of a sunflower seed), but is responsible for the production of a huge amount of hormones, including the synthesis of sex hormones in men and women. It is located behind the nasal cavity, ensures normal metabolism, controls the functioning of the thyroid, gonads, and adrenal glands.

The brain, being in calm state, consumes a huge amount of energy - about 10-20 times more than muscles (relative to their mass). Consumption is within 25% of all available energy.

Midbrain

The midbrain has a relatively simple structure, small in size, and includes two main parts: the roof (the centers of hearing and vision are located in the subcortical part); legs (contain conducting pathways). It is also customary to include black matter and red nuclei in the structure of the cloth.

The subcortical centers, which are part of this department, work to maintain the normal functioning of the hearing and vision centers. Also located here are the nerve nuclei that ensure the functioning of the eye muscles, the temporal lobes that process various auditory sensations, turning them into sound images familiar to humans, and the temporo-parietal node.

The following functions of the brain are also distinguished: controlling (together with the medulla oblongata) the reflexes that arise when exposed to a stimulus, helping with orientation in space, forming an appropriate reaction to stimuli, turning the body in the desired direction.

The gray matter in this part is high concentration nerve cells that form the nerve nuclei inside the skull.

The brain actively develops between the ages of two and eleven years. Most effective method improving their intellectual abilities is engaging in an unfamiliar activity.

Medulla

An important department of the central nervous system, which in various medical descriptions called bulbus. It is located between the cerebellum, pons, dorsal region. The bulbus, being part of the central nervous system trunk, is responsible for the functioning respiratory system, regulation blood pressure, which is vital for a person.

In this regard, if this section is damaged in any way ( mechanical damage, pathologies, strokes, etc.), then the probability of a person’s death is high.

The most important functions of the oblongata are:

• Working together with the cerebellum to ensure balance and coordination of the human body.
• The department includes nervus vagus with vegetative fibers, which helps ensure the functioning of the digestive and cardiovascular systems and blood circulation.
• Ensuring the swallowing of food and liquids.
• Presence of coughing and sneezing reflexes.
• Regulation of the respiratory system and blood supply to individual organs.

The medulla oblongata, the structure and functions of which differ from spinal cord, has many common structures with it.

The brain contains about 50-55% fat and in terms of this indicator it is far ahead of other organs of the human body.

Cerebellum

From an anatomical point of view, it is customary to distinguish between the posterior and anterior edges, the inferior and superior surfaces in the cerebellum. This zone has middle section and hemispheres divided into three lobes by grooves. This is one of the most important structures of the brain.

The main function of this department is to regulate the work skeletal muscles. Together with the cortical layer, the cerebellum takes part in the coordination of voluntary movements, which occurs due to the presence of connections between the department and receptors located in skeletal muscles, tendons, and joints.

The cerebellum also influences the regulation of body balance during human activity and while walking, which is carried out in conjunction with vestibular apparatus semicircular canals of the inner ear, which transmit information about the position of the body and head in space to the central nervous system. This is one of the most important functions of the brain.

The cerebellum provides coordination of skeletal muscle movements with the help of conductive fibers that pass from it to the anterior horn of the spinal cord to the place where the peripheral motor nerves of skeletal muscles begin.

Tumors can form on the cerebellum as a result of cancerous lesions of the region. The disease is diagnosed using

Scientists distinguish three main parts in the human brain: the hindbrain, midbrain And forebrain. All three are clearly visible already in a four-week embryo in the form of “brain bubbles.” Historically, the hindbrain and midbrain are considered more ancient. They are responsible for vital internal functions body: maintaining blood flow, breathing. The forebrain is responsible for human forms of communication with the outside world (thinking, memory, speech), which will interest us primarily in the light of the problems discussed in this book.

To understand why each disease affects the patient's behavior differently, you need to know the basic principles of brain organization.

1. The first principle is division of functions by hemispheres - lateralization. The brain is physically divided into two hemispheres: left and right. Despite their external similarity and the active interaction provided by big amount special fibers, functional asymmetry in the functioning of the brain can be seen quite clearly. Copes with some functions better right hemisphere(for most people it is responsible for figurative and creative work), and with others left (associated with abstract thinking, symbolic activity and rationality).
2. The second principle is also related to the distribution of functions across different areas of the brain. Although this organ works as a single whole and many higher human functions are provided by coordinated work different parts, the “division of labor” between the lobes of the cerebral cortex can be traced quite clearly.

In the cerebral cortex it is possible to distinguish four lobes: occipital, parietal, temporal and frontal. In accordance with the first principle - the principle of lateralization - each lobe has its own pair.

The frontal lobes can be called the command post of the brain. There are centers here that are not so much responsible for separate action, how many provide such qualities as independence and initiative of a person, his ability for critical self-evaluation. Damage to the frontal lobes causes carelessness, meaningless aspirations, fickleness and a tendency to make inappropriate jokes. With the loss of motivation due to atrophy of the frontal lobes, a person becomes passive, loses interest in what is happening, and remains in bed for hours. Often others mistake this behavior for laziness, not suspecting that changes in behavior are a direct consequence of the death of nerve cells in this area of ​​the cerebral cortex

According to views modern science Alzheimer's disease, one of the most common causes of dementia, is caused when protein deposits form around (and within) neurons, preventing those neurons from communicating with other cells and causing them to die. Because the effective ways Scientists have not found the main method to prevent the formation of protein plaques drug control with Alzheimer's disease, there remains an impact on the functioning of the mediators that ensure communication between neurons. In particular, acetylcholinesterase inhibitors affect acetylcholine, and memantine drugs affect glutamate. Others mistake this behavior for laziness, not suspecting that changes in behavior are a direct consequence of the death of nerve cells in this area of ​​the cerebral cortex.

An important function of the frontal lobes is control and behavior management. It is from this part of the brain that the command comes, preventing the performance of socially undesirable actions (for example, grasp reflex or unseemly behavior towards others). When this zone is affected in dementia patients, it is as if their internal limiter is turned off, which previously prevented them from expressing obscenities and using obscene words.

The frontal lobes are responsible for arbitrary actions, for their organization and planning, as well as mastering skills. It is thanks to them that gradually work that initially seemed complex and difficult to complete becomes automatic and does not require much effort. If frontal lobes damaged, a person is doomed to do his work every time as if for the first time: for example, his ability to cook, go to the store, etc. falls apart. Another variant of disorders associated with the frontal lobes is the patient’s “fixation” on the action being performed, or perseveration. Perseveration can manifest itself both in speech (repetition of the same word or whole phrase) and in other actions (for example, aimlessly moving objects from place to place).

The dominant (usually left) frontal lobe has many areas responsible for different aspects of speech person, his attention and abstract thinking.

Let us finally note the participation of the frontal lobes in maintaining an upright body position. When they are affected, the patient develops a shallow mincing gait and a bent posture.

Temporal lobes in upper sections process auditory sensations, turning them into sound images. Since hearing is the channel through which speech sounds are transmitted to humans, the temporal lobes (especially the dominant left) play a critical role in facilitating speech communication. It is in this part of the brain that the recognition and filling with meaning words addressed to a person, as well as the selection of language units to express their own meanings. The non-dominant lobe (right in right-handed people) is involved in recognizing intonation patterns and facial expressions.

The anterior and medial portions of the temporal lobes are associated with the sense of smell. Today it has been proven that the appearance of problems with the sense of smell in an elderly patient may be a signal of developing, but not yet identified, Alzheimer's disease.

A small, seahorse-shaped area on the inner surface of the temporal lobes (the hippocampus) controls human long-term memory. It is the temporal lobes that store our memories. The dominant (usually left) temporal lobe deals with verbal memory and object names, the non-dominant is used for visual memory.

Simultaneous damage to both temporal lobes leads to serenity, loss of visual recognition and hypersexuality.

The functions performed by the parietal lobes differ for the dominant and non-dominant sides.

The dominant side (usually the left) is responsible for the ability to understand the structure of the whole through the correlation of its parts (their order, structure) and for our the ability to put parts together into a whole. This applies to the most different things. For example, to read you need to be able to put letters into words and words into phrases. Same with numbers and figures. The same share allows you to master a sequence of related movements necessary to achieve a certain result (a disorder of this function is called apraxia). For example, the inability to dress independently, often noted in patients with Alzheimer's disease, is not caused by impaired coordination, but by forgetting the movements necessary to achieve a specific goal.

The dominant side is also responsible for feeling of your body: for distinguishing its right and left parts, for knowledge of the relationship of a separate part to the whole.

The non-dominant side (usually the right) is the center that, by combining information from the occipital lobes, provides three-dimensional perception of the surrounding world. Disruption of this area of ​​the cortex leads to visual agnosia - the inability to recognize objects, faces, or the surrounding landscape. Because visual information is processed in the brain separately from information coming from other senses, the patient in some cases has the opportunity to compensate for problems in visual recognition. For example, a patient who does not recognize loved one in person, can recognize him by his voice when talking. This side is also involved in the spatial orientation of the individual: the dominant parietal lobe is responsible for the internal space of the body, and the non-dominant one is responsible for recognizing objects in external space and for determining the distance to these objects and between them.

Both parietal lobes are involved in the perception of heat, cold and pain.

The occipital lobes are responsible for processing of visual information. In fact, everything that we see, we do not see with our eyes, which only record the irritation of the light acting on them and translate it into electrical impulses. We “see” with the occipital lobes, which interpret signals from the eyes. Knowing this, it is necessary to distinguish between weakened visual acuity in an elderly person and problems associated with his ability to perceive objects. Visual acuity (the ability to see small objects) depends on the work of the eyes, perception is a product of the work of the occipital and parietal lobes of the brain. Information about color, shape, and motion is processed separately in the occipital lobe of the cortex before being received in the parietal lobe to be converted into a three-dimensional representation. When communicating with dementia patients, it is important to take into account that their failure to recognize surrounding objects may be caused by the inability of normal signal processing in the brain and has nothing to do with visual acuity.

Completing short story about the brain, it is necessary to say a few words about its blood supply, since problems are in its vascular system– one of the most common (and in Russia, perhaps the most common) causes of dementia.

For normal operation neurons they need constant energy supply, which they receive thanks to three arteries supplying the brain: two internal carotid arteries and the main artery. They connect to each other and form an arterial (Willisian) circle, which allows you to nourish all parts of the brain. When, for some reason (for example, a stroke), the blood supply to certain parts of the brain is weakened or completely stopped, neurons die and dementia develops.

Often in science fiction novels (and in popular science publications) the work of the brain is compared to the work of a computer. This is not true for many reasons. Firstly, unlike a man-made machine, the brain was formed as a result of a natural process of self-organization and does not require any external program. Hence the radical differences in the principles of its operation from the functioning of an inorganic and non-autonomous device with an embedded program. Secondly (and for our problem this is very important), the various fragments of the nervous system are not connected in a rigid way, like computer blocks and cables stretched between them. The connection between cells is incomparably more subtle, dynamic, responsive to many various factors. This is the power of our brain, allowing it to sensitively respond to the slightest failures in the system and compensate for them. And this is also its weakness, since not a single one of these failures goes away without a trace, and over time their combination reduces the potential of the system, its ability to perform compensatory processes. Then changes begin in a person’s condition (and then in his behavior), which scientists call cognitive disorders and which over time lead to a disease such as.

A person is a complex organism, consisting of many organs united into a single network, the work of which is regulated precisely and impeccably. The main function of regulating the work of the body is performed by the central nervous system(CNS). This is a complex system, including several organs and peripheral nerve endings and receptors. The most important body This system is the brain - a complex computing center responsible for the proper functioning of the entire organism.

General information about the structure of the brain

They have been trying to study it for a long time, but for all this time scientists have not been able to accurately and unambiguously answer the question 100% of what it is and how this organ works. Many functions have been studied, for some there are only guesses.

Visually, it can be divided into three main parts: the cerebellum and the cerebral hemispheres. However, this division does not reflect the full versatility of the functioning of this organ. In more detail, these parts are divided into departments responsible for certain functions of the body.

Oblong section

The human central nervous system is an inextricable mechanism. A smooth transitional element from the spinal segment of the central nervous system is the medulla oblongata. Visually, it can be represented in the form of a truncated cone with the base at the top or a small onion head with thickenings diverging from it - connecting to the intermediate section.

There are three various functions departments - sensory, reflex and conductive. Its tasks include monitoring the main protective ( vomiting reflex, sneezing, coughing) and unconscious reflexes (heartbeat, breathing, blinking, salivation, secretion of gastric juice, swallowing, metabolism). In addition, the medulla oblongata is responsible for such senses as balance and coordination of movements.

Midbrain

The next department responsible for communication with the spinal cord is the middle one. But the main function of this department is processing nerve impulses and adjusting performance hearing aid and the human visual center. After processing the received information, this formation sends impulse signals to respond to stimuli: turning the head towards the sound, changing body position in case of danger. Additional functions include regulation temperature regime body, muscle tone, excitement.

The human midbrain is responsible for such an important ability of the body as sleep.

The middle section has a complex structure. There are 4 clusters of nerve cells - tubercles, two of which are responsible for visual perception, two others for hearing. Nerve clusters are connected to each other and to other parts of the brain and spinal cord by the same nerve-conducting tissue, visually similar to legs. The total size of the segment does not exceed 2 cm in an adult.

Diencephalon

The department is even more complex in structure and functions. Anatomically, the diencephalon is divided into several parts: Pituitary gland. This is a small appendage of the brain that is responsible for the secretion of necessary hormones and regulation of the body's endocrine system.

Conventionally divided into several parts, each of which performs its own function:

• The adenohypophysis is a regulator of peripheral endocrine glands.
• The neurohypophysis is connected to the hypothalamus and accumulates the hormones it produces.

Hypothalamus

A small area of ​​the brain whose most important function is to control heart rate and blood pressure in blood vessels. Additionally, the hypothalamus is responsible for part emotional manifestations by producing the necessary hormones to suppress stressful situations. Another important function is the control of hunger, satiety and thirst. To top it off, the hypothalamus is the center of sexual activity and pleasure.

Epithalamus

The main task of this department is to regulate the daily biological rhythm. With the help of produced hormones, it influences the duration of sleep at night and normal wakefulness during the day. It is the epithalamus that adapts our body to the conditions of “daylight” and divides people into “night owls” and “larks”. Another task of the epithalamus is to regulate the body’s metabolism.

Thalamus

This formation is very important for a correct understanding of the world around us. It is the thalamus that is responsible for processing and interpreting impulses coming from peripheral receptors. This information processing center brings together data from the visual nerves, hearing aid, temperature receptors of the body, olfactory receptors and pain points.

Posterior

Like previous sections, the hindbrain includes subsections. The main part is the cerebellum, the second is the pons, which is a small cushion of nerve tissue that connects the cerebellum with other parts and the blood vessels that supply the brain.

Cerebellum

In its shape, the cerebellum resembles the cerebral hemispheres; it consists of two parts, connected by a “worm” - a complex of conductive nerve tissue. The main hemispheres consist of nerve cell nuclei, or “gray matter,” folded together to increase surface area and volume. This part is located in the back of the head cranium and completely occupies its entire posterior fossa.

The main function of this department is coordination motor functions. However, the cerebellum does not initiate movements of the arms or legs - it only controls accuracy and clarity, the order of movements, motor skills and posture.

The second important task is the regulation of cognitive functions. These include: attention, understanding, awareness of language, regulation of the feeling of fear, sense of time, awareness of the nature of pleasure.

Large hemispheres of the brain

The bulk and volume of the brain is located in the terminal section or cerebral hemispheres. There are two hemispheres: the left - mostly responsible for analytical thinking and speech functions of the body, and the right - whose main task is abstract thinking and all processes associated with creativity and interaction with the outside world.

Structure of the telencephalon

The cerebral hemispheres are the main “processing unit” of the central nervous system. Despite their different “specializations,” these segments complement each other.

The greater hemispheres are complex system interaction between the nuclei of nerve cells and nerve-conducting tissues connecting the main areas of the brain. The upper surface, called the cortex, consists of a huge number of nerve cells. It is called gray matter. In the light of general evolutionary development, the cortex is the youngest and most developed formation of the central nervous system and highest development reached precisely in humans. It is she who is responsible for the formation of higher neuropsychic functions and complex forms of human behavior. To increase the usable area, the surface of the hemispheres is assembled into folds or convolutions. The inner surface of the cerebral hemispheres consists of white matter– processes of nerve cells responsible for conducting nerve impulses and communicating with the rest of the central nervous system.

In turn, each of the hemispheres is conventionally divided into 4 parts or lobes: occipital, parietal, temporal and frontal.

Occipital lobes

The main function of this conditional part is the processing of neural signals coming from the visual centers. It is here that the usual concepts of color, volume and other three-dimensional properties of a visible object are formed from light stimuli.

Parietal lobes

This segment is responsible for the occurrence pain and processing of signals from the body's thermal receptors. That's it for them general work ends.

The parietal lobe of the left hemisphere is responsible for structuring information packages, allowing you to operate with logical operators, count and read. Also, this area forms awareness of the holistic structure of the human body, determination of the right and left parts, coordination of individual movements into a single whole.

The right one is engaged in generalizing information flows that are generated by the occipital lobes and the left parietal lobe. In this area, a general three-dimensional picture of the perception of the environment, spatial position and orientation, and calculation of perspective are formed.

Temporal lobes

This segment can be compared to a computer’s “hard drive” – a long-term storage of information. This is where all the memories and knowledge of a person collected over a lifetime are stored. The right temporal lobe is responsible for visual memory - image memory. Left - all concepts and descriptions of individual objects are stored here, interpretation and comparison of images, their names and characteristics takes place.

As for speech recognition, both temporal lobes are involved in this procedure. However, their functions are different. If the left lobe is called upon to recognize the semantic load of the words heard, then the right lobe interprets the intonation coloring and compares it with the speaker’s facial expressions. Another function of this part of the brain is the perception and decoding of neural impulses coming from the olfactory receptors of the nose.

Frontal lobes

This part is responsible for such properties of our consciousness as critical self-esteem, adequacy of behavior, awareness of the degree of meaninglessness of actions, and mood. General behavior person also depends on proper operation frontal lobes of the brain, disturbances lead to inappropriate and antisocial behavior. The process of learning, mastering skills, and acquiring conditioned reflexes depends on the proper functioning of this part of the brain. This also applies to the degree of activity and curiosity of a person, his initiative and awareness of decisions.

To systematize the functions of the GM, they are presented in the table:

Interaction of brain parts

In addition to the fact that each part of the brain has its own tasks, the holistic structure determines consciousness, character, temperament and others psychological characteristics behavior. The formation of certain types is determined varying degrees influence and activity of one or another segment of the brain.

The first psychotype or choleric. The formation of this type of temperament occurs with the dominant influence of the frontal lobes of the cortex and one of the subdivisions diencephalon– hypothalamus. The first generates determination and desire, the second section reinforces these emotions with the necessary hormones.

The characteristic interaction of the departments that determines the second type of temperament - sanguine - is the joint work of the hypothalamus and hippocampus (the lower part of the temporal lobes). The main function of the hippocampus is to maintain short-term memory and convert acquired knowledge into long-term memory. The result of such interaction is an open, inquisitive and interested type of human behavior.

Melancholic people are the third type of temperamental behavior. This variant is formed due to increased interaction between the hippocampus and another formation of the cerebral hemispheres - the amygdala. At the same time, the activity of the cortex and hypothalamus is reduced. The amygdala takes on the entire “blow” of exciting signals. But since the perception of the main areas of the brain is inhibited, the reaction to excitement is low, which in turn affects behavior.

In turn, by forming strong connections, the frontal lobe is able to set an active pattern of behavior. When the cortex of this area interacts with the tonsils, the central nervous system generates only highly significant impulses, while ignoring unimportant events. All this leads to the formation of a Phlegmatic model of behavior - a strong, purposeful person with an awareness of priority goals.

The brain is a powerful control center that sends commands throughout the body and controls the progress of their implementation. It is thanks to him that we perceive the world and are able to interact with it. What kind of brain has modern man, his intellect, thinking, were the result of millions of years of continuous evolution of mankind, his structure is unique.

The brain is characterized by division into zones, each of which specializes in performing its own specific functions. It is important to have information about what functions each zone performs. Then you can easily understand why specific symptoms for such common diseases as Alzheimer's disease, stroke, etc. Disorders can be regulated with medication, as well as with the help special exercises, physiotherapy.

The brain is structurally divided into:

• rear;
• average;
• front.

Each of them has their own role.

In an embryo, the head develops faster than other parts of the body. In a one-month-old embryo, all three parts of the brain can be easily seen. During this period they look like “brain bubbles”. The brain of a newborn is the most developed system in his body.

Scientists attribute the hindbrain and midbrain to more ancient structures. It is this part that is entrusted with the most important functions– maintaining breathing and blood circulation. The boundaries of their functions are clearly separated. Each gyrus does its job. The more pronounced the groove became during development, the more functions it could perform. But the anterior section provides everything that connects us with external environment(speech, hearing, memory, ability to think, emotions).

There is an opinion that a woman's brain is smaller than a man's brain. Data from modern hardware studies, in particular on a tomograph, have not confirmed this. This definition can easily be called erroneous. The brain of different people may differ in size and weight, but this does not depend on gender.

Knowing the structure of the brain, you can understand why certain diseases appear and what their symptoms depend on.

Structurally, the brain consists of two hemispheres: right and left. Externally they are very similar and interconnected a huge amount nerve fibers. Each person has one side that is dominant, right-handed people have the left side, and left-handed people have the right side.

There are also four lobes of the brain. You can clearly see how the functions of the shares are differentiated.

What are shares?

The cerebral cortex has four lobes:

1. occipital;
2. parietal;
3. temporal;
4. frontal

Each share has a pair. All of them are responsible for maintaining the vital functions of the body and contact with the outside world. If injury, inflammation, or disease of the brain occurs, the function of the affected area may be completely or partially lost.

Frontal

These lobes have a frontal location, they occupy the forehead area. Let's figure out what the frontal lobe is responsible for. The frontal lobes of the brain are responsible for sending commands to all organs and systems. They can be figuratively called a “command post.” It would take a long time to list all their functions. These centers are responsible for all actions and provide the most important human qualities(initiative, independence, critical self-esteem, etc.). When they are defeated, a person becomes carefree, changeable, his aspirations have no meaning, he is prone to inappropriate jokes. Such symptoms may indicate atrophy of the frontal lobes, leading to passivity, which is easily mistaken for laziness.

Each lobe has a dominant and auxiliary part. For right-handed people, the left area will be dominant and vice versa. If you separate them, it is easier to understand which functions are assigned to a specific area.

It is the frontal lobes that control human behavior. This part of the brain sends commands that prevent a specific antisocial action from being performed. It is easy to notice how dementia patients are affected this zone. The internal limiter is turned off, and the person can tirelessly use obscene language, indulge in obscenities, etc.

The frontal lobes of the brain are also responsible for planning, organizing voluntary actions, and mastering the necessary skills. Thanks to them, those actions that seem very difficult at first become automatic over time. But when these areas are damaged, the person performs the actions as if anew each time, and automaticity is not developed. Such patients forget how to go to the store, how to cook, etc.

When the frontal lobes are damaged, perseveration can occur, in which patients literally become fixated on performing the same action. A person may repeat the same word, phrase, or constantly move objects around aimlessly.

The frontal lobes have a main, dominant, most often left, lobe. Thanks to her work, speech, attention, and abstract thinking are organized.

It is the frontal lobes that are responsible for maintaining the human body in vertical position. Patients with their lesions are distinguished by a hunched posture and a mincing gait.

Temporal

They are responsible for hearing, turning sounds into images. They provide speech perception and communication in general. The dominant temporal lobe of the brain allows you to fill the words you hear with meaning and select the necessary lexemes in order to express your thoughts. The non-dominant helps to recognize intonation and determine the expression of a human face.

The anterior and middle temporal regions are responsible for the sense of smell. If it is lost in old age, this may signal a nascent one.

The hippocampus is responsible for long-term memory. It is he who stores all our memories.

If both temporal lobes are affected, a person cannot assimilate visual images, becomes serene, and his sexuality goes through the roof.

Parietal

In order to understand the functions of the parietal lobes, it is important to understand that the dominant and non-dominant side will do different jobs.

The dominant parietal lobe of the brain helps to understand the structure of the whole through its parts, their structure, order. Thanks to her, we know how to put individual parts into a whole. The ability to read is very indicative of this. To read a word, you need to put the letters together, and you need to create a phrase from the words. Manipulations with numbers are also carried out.

The parietal lobe helps to link individual movements into a complete action. When this function is disrupted, apraxia is observed. Patients cannot perform basic actions, for example, they are not able to get dressed. This happens with Alzheimer's disease. A person simply forgets how to make the necessary movements.

The dominant area helps you feel your body, distinguish between right and left side, relate parts and the whole. This regulation is involved in spatial orientation.

The non-dominant side (in right-handed people it is right) combines information that comes from the occipital lobes and allows three-dimensional perception the world. If the non-dominant parietal lobe is disrupted, visual agnosia may occur, in which a person is unable to recognize objects, landscapes, or even faces.

The parietal lobes are involved in the perception of pain, cold, and heat. Their functioning also ensures orientation in space.

Occipital

The occipital lobes process visual information. It is with these lobes of the brain that we actually “see.” They read signals that come from the eyes. The occipital lobe is responsible for processing information about shape, color, and movement. The parietal lobe then turns this information into a three-dimensional image.

If a person stops recognizing familiar objects or loved ones, this may indicate a dysfunction in the occipital or temporal lobe of the brain. In a number of diseases, the brain loses the ability to process received signals.

How the hemispheres of the brain are connected

The hemispheres are connected by the corpus callosum. This is a large plexus of nerve fibers through which the signal is transmitted between the hemispheres. Adhesions are also involved in the joining process. There is a posterior, anterior, and superior commissure (fornix commissure). This organization helps to divide the functions of the brain between its individual lobes. This feature has been developed over millions of years of continuous evolution.

Conclusion

So, each department has its own functional load. If a separate lobe suffers due to injury or disease, another zone may take over some of its functions. Psychiatry has accumulated a lot of evidence of such redistribution.

It is important to remember that the brain cannot function fully without nutrients. The diet should have a variety of foods from which nerve cells will receive necessary substances. It is also important to improve blood supply to the brain. It is promoted by playing sports, walking on fresh air, moderate amount spices in the diet.

Medulla may be confused with the functions of the spinal cord! In the nuclei of gray matter (accumulation of dendrites) there are defense reflex centers- blinking and vomiting, coughing, sneezing, and also the medulla oblongata allows you to inhale and exhale, secrete saliva (automatically, we cannot control this reflex), swallow, secrete gastric juice- also automatic. The medulla oblongata performs reflex and conductive functions.

Bridge responsible for the movement of eyeballs and facial expressions.

Cerebellum responsible for coordinating movement.

Midbrain responsible for clarity of vision and hearing. It regulates the size of the pupil and the curvature of the lens. Regulates muscle tone. It contains the centers of the orienting reflex

Forebrain- the largest section of the brain, which is divided into two halves.

1) Diencephalon, which is divided into three parts:

a) Upper

b) Lower (aka hypotholamus) - regulates metabolism and energy, that is: fasting - saturation, thirst - quenching.

c) Central (thalamus) - here the first processing of information from the senses occurs.

2) Large hemispheres brain

a) Left hemisphere - for right-handed people, speech centers are located here, and the left hemisphere is responsible for the movement of the right leg, right hand etc

b) Right hemisphere - in right-handed people, the whole situation is perceived here (at what distance is the fence, what volume is it, etc.), and is also responsible for the movement of the left leg, left hand, etc.

Occipital lobe- location of visual areas formed by neurons.

Temporal lobe- location of auditory zones.

Parietal lobe- responsible for musculocutaneous sensitivity.

The inner surface of the temporal lobes is the olfactory and gustatory zones.

Frontal lobes front part - active behavior.

In front of the central gyrus is the motor zone.

Autonomic nervous system. According to its structure and properties autonomic nervous system (ANS) is different from somatic(SNS) with the following features:

1. ANS centers are located in different parts of the central nervous system: in the middle and medulla oblongata of the brain, sternolumbar and sacral segments of the spinal cord. Nerve fibers arising from the nuclei of the middle and medulla oblongata and from the sacral segments of the spinal cord, form parasympathetic division of the ANS. Fibers emerging from the nuclei of the lateral horns of the sternolumbar segments of the spinal cord form sympathetic division of the ANS.

2. Nerve fibers, leaving the central nervous system, do not reach the innervated organ, but are interrupted and come into contact with the dendrite of another nerve cell, the nerve fiber of which already reaches the innervated organ. At the points of contact, clusters of nerve cell bodies form nodes, or ganglia, of the ANS. Thus, the peripheral part of the motor sympathetic and parasympathetic nerve pathways is built from two neurons sequentially following each other (Fig. 13.3). The body of the first neuron is located in the central nervous system, the body of the second is in the autonomic nerve node (ganglion). The nerve fibers of the first neuron are called preganglionic, second -postganglionic

.

Fig.3. Reflex arc diagram of somatic (a) and autonomic (6) reflexes: 1 - receptor; 2 - sensory nerve; 3 - central nervous system; 4 - motor nerve; 5 -working body -muscle, gland; TO - contact (intercalary) neuron; G - autonomic ganglion; 6.7 - pre- and postganglionic nerve fiber.

3. The ganglia of the sympathetic division of the ANS are located on both sides of the spine, forming two symmetrical chains of nerve nodes connected to each other. The ganglia of the parasympathetic division of the ANS are located in the walls of the innervated organs or near them. Therefore, in the parasympathetic section of the ANS, post-ganglionic fibers, unlike sympathetic ones, are short.

4. Nerve fibers of the ANS are 2-5 times thinner than the fibers of the SNS. Their diameter is 0.002-0.007 mm, therefore the speed of excitation through them is lower than through SNS fibers, and reaches only 0.5-18 m/s (for SNS fibers - 30-120 m/s). Most internal organs have double innervation, i.e. each of them is approached nerve fibers both sympathetic and parasympathetic divisions VNS. They have the opposite effect on the functioning of organs. Thus, excitation of the sympathetic nerves increases the rhythm of contractions of the heart muscle and narrows the lumen of blood vessels. The opposite effect is associated with excitation of the parasympathetic nerves. The meaning of the double innervation of internal organs lies in the involuntary contractions of the smooth muscles of the walls. In this case, reliable regulation of their activity can only be ensured by double innervation, which has the opposite effect.