What is white matter. Signs of lesions in the white matter of the brain. Why do you need white and gray matter of the spinal cord, where is it. anterior brain tissue. Damage to white or gray matter

Psychopathies are painful personality changes, with emotional disturbances, volitional disorders, pathological experiences and bouts of inappropriate behavior. People suffering from these types of disorders may retain intellectual abilities, but often lose them. The development of psychopathy gradually leads to the fact that patients develop inappropriate behavior in society, the ability to normal social adaptation is lost. Psychopathic manifestations are especially difficult if painful changes begin in childhood.

The representative of the German school of psychiatry, K. Schneider, argued that the personality of a psychopath exposes both himself and the people around him to suffering. Psychopathic manifestations can undergo dynamic changes with the age and development of a person. Especially clinical symptoms increase in adolescence and in the elderly.

Causes of psychopathy

Note:provoking factors in the development of pathological changes can be severe diseases of internal organs, severe stressful situations. According to official data, up to 5% of the population suffers from psychopathy.

Despite the prevalence of this pathology, its causal factors have not been studied enough. Scientists differ both in some questions of classification, and in the mechanisms of development of painful changes.

In a separate large group of causes of psychopathy, brain lesions are identified, which are caused by:

• environmental pollution;
• severe infectious diseases;
• traumatic head injuries;
• poisoning;
• elevated .

The listed groups of harmful effects lead to painful changes in the brain, nervous system, and as a result, severe changes occur in the psyche.

Also, social factors are of great importance in the development of pathology: the atmosphere in the family, school, work teams, etc. Especially these conditions play a role in childhood.

The hereditary nature of the transmission of psychopathy is of no small importance.

The main classifications of psychopathy

The problem of psychopathy was of interest to many world-class scientists. This has led to the creation of many classifications. We will consider the most common, most commonly used in clinical medicine.

According to the main groups (O.V. Kebrikov), the following are distinguished:

• nuclear psychopathy(depending on the constitutional type of a person, in which the main role is assigned to heredity);
• marginal psychopathy(arising from problems of a biological nature and social causes);
• organic psychopathy(caused by organic lesions of the brain, and manifested at the stage of personality development, at the age of 6-10 years).

An additional role in the development of psychopathic traits is played by:

• separation of the child from parents, family;
• overprotectiveness, developing a painful self-importance;
• lack or complete lack of attention to their children;
• "Cinderella" syndrome - relegation to the background of the adopted child, or the formation of a complex in children due to increased parental attention paid to one child at the expense of others;
• the “idol” phenomenon is a painful perception of caring for other children by a child – the “favorite” of the family society.

Note:the existing psychopathic character traits can clearly manifest themselves with defects in upbringing and give painful emotional reactions and pathological behavior.

The main medical classification of psychopathy divides the disease according to the leading psychopathological syndrome.

In practical medicine, psychopathy is distinguished:

• asthenic;
• psychasthenic;
• schizoid"
• hysterical;
• epileptoid;
• paranoid;
• excitable;
• affective;
• heboid;
• with sexual disorders and perversions

Symptoms of the main clinical forms of psychopathy

The main manifestations of psychopathy depend on the developing type of the disease.

Symptoms of asthenic psychopathy

This form is characteristic of people of a weak psychophysical type, prone to increased vulnerability, hypersensitivity, quickly exhausted during strong nervous and physical stress. They are characterized by excessive anxiety (fearfulness), cowardly actions, frequent indecision, if necessary, to take responsibility for themselves.

Deep and prolonged experiences lead to a permanently depressed mood. Over time, an excessive tendency to take care of one's health appears, develop.

The asthenic psychopath is constantly tired, good health for him is an extreme rarity. Excessive pedantry, acrimony prevail in character traits, there is a certain life algorithm, it is very difficult for the patient to go beyond the boundaries of which.

This form is also characteristic of a weak type of nervous system. The main feature of patients is the predominance of the second signaling system. It is characteristic of people of the mental type. The behavior of these psychopaths is dominated by corrosiveness and excessive analysis of events and actions, especially their own. The patient is concerned about abstract, unimportant questions. For example, the color of the shirt in which you need to go out. Reasoning about whether it is right now to go in these clothes can lead a person to a dead end, and he will not go to the place he needs at all. Among the main symptoms of psychasthenic psychopathy are painful doubts (“mental chewing gum”) that arise for any, the most insignificant reason. Psychasthenics are characterized by pettiness and pedantry, which reach the level of obsessive states to an extreme degree.

Psychasthenics are constantly engaged in self-reexamination. Obsessive thoughts distract patients from real life. The insufficiency of the first signaling system makes patients emotionally narrowed, "flat" and indifferent.

Patients with this form of the disease look closed, avoid people and communication, are prone to self-immersion (pronounced introverts) . Thoughts and ideas of patients are obscure to others, very peculiar. Appearance, hobbies are unusual. There is a detachment from the interests of the outside world.

They say about such people that they are “not of this world”, eccentric and indifferent to themselves and others. Often they have developed intellectual abilities. . According to I.V. Chess allocate: sthenic a type of schizoid psychopathy (with symptoms of withdrawal, emotional dullness, rigidity and coldness) and asthenic type (closedness is noticeable, accompanied by daydreaming, anxiety and combined with strange hobbies - “freaks”).

Typology of a person with a predominance of the first signal system. Characteristic of the artistic type of nervous activity. Vivid emotions come to the fore in the life of this category of patients. , that are prone to rapid polar changes . This leads to mood swings, unstable behavior.

Patients suffering from this form are very proud, self-centered, with a characteristic feature - to be constantly in the center of attention (demonstrative behavior). These patients are characterized by inventing stories, a tendency to fantasize and embellish facts, sometimes they “lie” so much that they themselves begin to believe in their writings. This form of psychopathy often develops symptoms .

People suffering from this type of mental disorder have viscous thinking, obsession with details, and extreme pedantry. Their thinking is stiff, hard "swaying". Among the main symptoms are pettiness, scrupulousness and excessive prudence. .

In behavior, there are sharp changes in attitude towards people: from sugary obsequiousness to outbursts of anger and intransigence. One of the features of the type is the inability and unwillingness to forgive. Epileptoid psychopaths can harbor anger and resentment all their lives, and at the slightest opportunity resort to revenge. Outbursts of anger are strong and prolonged. Patients of this form of the disease often exhibit sadistic tendencies.

Patients of this group are prone to one-sided and obsessive thinking, are prone to the formation of overvalued ideas that can completely take over their volitional and emotional sphere. The most common manifestation of this morbid quality is suspicion.

A paranoid psychopath can find in each of his acquaintances the features of an intruder who is watching him. Often, patients attribute envy towards themselves to people around them. It seems to the patient that everyone wants to harm him, even doctors. Painful symptoms of paranoid psychopathy often manifest themselves in ideas of jealousy, fanatical thoughts, constant complaints. It is quite natural that the relationship of this category of psychopaths with other people is conflicting.

This group of patients is more prone to uncontrolled outbursts of anger, inappropriate actions, attacks of unmotivated and pronounced aggression. Psychopaths are overly demanding of other people, too touchy and selfish. They have little interest in the opinions of outsiders.

At the same time, patients with excitable psychopathy may show symptoms of depressive states, despair. The most often excitable type is inherent in alcoholics, drug addicts, socially pathological personalities (thieves, bandits). Among them is the largest percentage of offenders and persons who are examined by forensic medical examinations.

This type of mental disorder occurs in the form hyperthymia- a condition in which patients are characterized by a constantly elevated mood with a feeling of carelessness and activity. This type of patient is inclined to take on all the cases in a row, but not one of them is able to complete. There is frivolity, increased talkativeness, importunity and leadership tendencies. Affective psychopaths quickly find a common language with everyone and no less quickly get bored with their “stickiness”. They have a tendency to get into difficult, conflict situations.

The second type of disorder hypothymia, is the opposite of hyperthymia. Patients diagnosed with "affective psychopathy" are in a depressed state. They tend to see negative aspects in everything, express dissatisfaction with themselves and others, they often have hypochondriacal symptoms, and extreme degrees of pessimism are observed. They are closed and feel a sense of their own guilt in front of everyone, consider themselves guilty of everything that happens. At the same time, hypothymics expressed resentment. Any word can deeply hurt the patient.

The type of this pathological process contains deviations in the sphere of the concepts of duty, honor, conscience. Sick of a cruel disposition, merciless and selfish, with an atrophied concept of shame. General human norms do not exist for them. This type of psychopathy always proceeds in a severe form. Geboid psychopaths are characterized by sadism and indifference to the suffering of other people.

Symptoms of psychopathy with sexual perversions and disorders

The clinic of these disorders proceeds in combination with other types of psychopathy. Sexual perversions include pedophilia, sado-masochism, bestiality, transvestism and transsexualism. The forms of these deviations are constantly reviewed by specialists in order to determine the line between the symptoms of the disease and the variant of behavior within the framework of the mental norm.

Psychopathies run in cycles. Periods of improvement are replaced by exacerbations of the disease process. Psychopathies must be distinguished from personality accentuations (extreme degrees of manifestation of character).

Note:accentuations are not a pathology, although their manifestations may resemble psychopathy. Only a qualified psychiatrist can distinguish psychopathy from accentuation.

Treatment of psychopathy

Therapy of psychopathy begins with the elimination of the cause that triggered the development of clinical manifestations (infectious diseases, injuries, stress, diseases of internal organs, etc.)

Medical treatment includes:

• fortifying agents: vitamins, antioxidants, immunomodulators;
• sedatives (soothing in mild forms of pathology);
• tranquilizers (to stabilize the emotional background with constant overexcitation);
• neuroleptics (with affective forms);
• antidepressants (in cases of depression);
• sleeping pills (for stabilization in excitable forms of the disease);
• symptomatic (with problems with the heart, liver, kidneys).

Treatment of psychopathy must be accompanied by psychotherapy (hypnosis, waking suggestion, rational psychotherapy). Acupuncture, physiotherapy, especially electrosleep are widely used.

Prevention of psychopathy

Prevention of this group of diseases is possible only with large-scale measures at the state level, including the solution of socio-economic issues, the early detection of abnormal types of behavior in children and the creation of favorable conditions for their development, with gradual adaptation in society.

The task of medicine is to effectively treat somatic diseases.

Educational institutions should instill in children a healthy lifestyle, raise the cultural and educational level.

You will receive more detailed information about the course of psychopathy, methods of their diagnosis and treatment by watching this video review:

Lotin Alexander, medical columnist

The human brain is made up of white and gray matter. The first is everything that is filled between the gray matter on the cortex and On the surface there is a uniform layer of gray matter with nerve cells, the thickness of which is up to four and a half millimeters.

Let's study in more detail what is gray and white matter in the brain.

Space constraints prevented the inclusion of electro- or magnetoencephalographic data, but it is certain that, given the dynamic spatial and temporal dimensions of these data, it would be necessary to speak of "networks". Many issues need to be addressed, such as.

The relationship between age and the state of white matter

The fact that intelligence can be associated with an increase in gray matter volume and a decrease in brain glucose consumption under certain conditions. Know if experience and training can increase gray matter. Gender differences noted in some studies.

What are these substances made of?

The substance of the CNS is of two types: white and gray.

White matter consists of many nerve fibers and processes of nerve cells, the sheath of which is white.

The gray matter consists of processes. Nerve fibers connect different parts of the central nervous system and nerve centers.

Gray and white matter of the spinal cord

The heterogeneous substance of this organ is gray and white. The first is formed by a huge number of neurons that are concentrated in the nucleus and are of three types:

Lack of research related to the measurement of intelligence, imaging and genetic studies. Limits Inherent in Identification of the Neural Basis for General Intelligence. Choose from multiple conversation options. A map that unites the brain with mind maps.

The theory of paratheto-frontal integration of intelligence: a major contribution to the theory of intelligence. The Sleeping Brain, States of Consciousness, and the Human Mind. On the neural basis of crystallized intelligence. Integrative action in the fronto-parietal network: caring for the scattered brain.

About correlation images. Intelligence and reasoning are two different things. Intelligence, hormones, sex, brain size, and biochemistry: demonstrate causation prior to integration. A global approach is needed. Is it possible to expand the theory of parieto-frontal integration of intelligence and explain individual differences in performance and skills in everyday life?

• radicular cells;
• beam neurons;
• inner cells.

The white matter of the spinal cord surrounds the gray matter. It includes nerve processesconstituting three systems of fibers:

• intercalary and afferent neurons connecting different parts of the spinal cord;
• sensitive afferent, which are long centripetal;
• motor afferent or long centrifugal.

Medulla

From the course of anatomy, we know that the spinal cord passes into the medulla oblongata. Part of this brain is thicker at the top than at the bottom. Its average length is 25 millimeters, and its shape resembles a truncated cone.

It develops gravitational and auditory organs associated with respiration and blood circulation. Therefore, the nuclei of gray matter here regulate balance, metabolism, blood circulation, respiration, and coordination of movements.

Hind brain

This brain consists of the pons and the cerebellum. Consider the gray and white matter in them. The bridge is a large white ridge at the back of the base. On the one hand, its border with the legs of the brain is expressed, and on the other, with the oblong. If you make a cross section, then the white matter of the brain and the gray nucleus will be very visible here. Transverse fibers divide the pons into ventral and dorsal sections. In the ventral part, the white matter of the pathways is mainly present, and the gray matter here forms its nuclei.

The dorsal part is represented by nuclei: switching, sensory systems and cranial nerves.

The cerebellum is located under the occipital lobes. It includes the hemispheres and the middle part called the "worm". makes up the cerebellar cortex and nucleus, which are tent-shaped, spherical, cork-shaped and serrated. The white matter of the brain in this part is located under the cerebellar cortex. It penetrates all the gyri as white plates and consists of various fibers that either connect the lobules and gyri, or are directed to the inner nuclei, or connect sections of the brain.

midbrain

It starts from the middle brain bladder. On the one hand, it corresponds to the surface of the brainstem between and the superior medullary velum, and on the other hand, to the area between the mastoid bodies and the anterior part of the bridge.

It includes a cerebral aqueduct, on one side of which the boundary is provided by a roof, and on the other, by a cover of the legs of the brain. In the ventral section, the posterior perforated substance and the legs of the cerebrum are distinguished, and in the dorsal section, the roof plate and the handles of the lower and upper tubercles.

If we consider the white and gray matter of the brain in the cerebral aqueduct, we will see that the white surrounds the central gray matter, consisting of small cells and having a thickness of 2 to 5 millimeters. It consists of the trochlear, trigeminal and oculomotor nerves, together with the accessory nucleus of the latter and the intermediate.

diencephalon

It is located between the corpus callosum and the fornix, and fuses with the sides on the sides.

The gray matter here consists of nuclei that are associated with centers of sensitivity.
White matter is represented by conducting paths of different directions, guaranteeing the connection of formations with the cerebral cortex and nuclei. The diencephalon also includes the pituitary and pineal glands.

telencephalon

It is represented by two hemispheres, which are separated by a gap running along them. It is connected in depth by the corpus callosum and adhesions.

The cavity is represented by lateral ventricles located in one and the second hemisphere. These hemispheres are:

• a cloak of neocortex or six-layered cortex, differing in nerve cells;
• the striatum from the basal nuclei - ancient, old and new;
• partitions.

But sometimes there is another classification:

• olfactory brain;
• subcortex;
• gray matter of the cortex.

Without touching the gray matter, let's stop at once on the white.

About the features of the white matter of the hemispheres

The white matter of the brain occupies the entire space between the gray and basal nuclei. There is a huge amount of nerve fibers here. The white matter contains the following areas:

• the central substance of the internal capsule, corpus callosum and long fibers;
• radiant crown of divergent fibers;
• semi-oval center in the outer parts;
• substance located in the convolutions between the furrows.

Nerve fibers are:

• commissural;
• associative;
• projection.

The white matter includes nerve fibers that are connected by convolutions of one and the other cortex of the hemispheres and other formations.

Nerve fibers

Basically, commissural fibers are found in the corpus callosum. They are located in the cerebral commissures that connect the cortex on different hemispheres and symmetrical points.

Associative fibers group areas on one hemisphere. At the same time, short ones connect adjacent gyruses, and long ones - located at a far distance from each other.

Projection fibers connect the cortex with those formations that are located below, and further with the periphery.

If the internal capsule is viewed frontally in section, the lentiform nucleus and posterior pedicle will be visible. Projection fibers are divided into:

• fibers located from the thalamus to the cortex and in the opposite direction, they excite the cortex and are centrifugal;
• fibers directed to the motor nuclei of the nerves;
• fibers that conduct impulses to the muscles of the whole body;
• fibers directed from the cortex to the pontine nuclei, providing a regulatory and inhibitory effect on the work of the cerebellum.

Those projection fibers that are located closest to the cortex create a radiant crown. Then their main part passes into the internal capsule, where the white matter is located between the caudate and lenticular nuclei, as well as the thalamus.

On the surface there is an extremely complex pattern, where grooves and ridges alternate between them. They are called convolutions. Deep furrows divide the hemispheres into large sections, which are called lobes. In general, the furrows of the brain are deeply individual, they can be very different in different people.

The hemispheres have five lobes:

• frontal;
• parietal;
• temporal;
• occipital;
• island.

The central sulcus originates at the top of the hemisphere and moves down and forward to the frontal lobe. The area behind the central sulcus is the parietal lobe th, which ends with the parietal-occipital sulcus.

The frontal lobe is divided into four convolutions, vertical and horizontal.
The lateral surface is represented by three convolutions, which are delimited from each other.

The furrows of the occipital lobe are variable. But everyone, as a rule, has a transverse one, which is connected to the end of the interparietal sulcus.

On the parietal lobe there is a groove running parallel to the central horizontally and merging with another groove. Depending on their location, this share is divided into three convolutions.

The island has a triangular shape. It is covered with short convolutions.

Brain damage

Thanks to the achievements of modern science, it has become possible to conduct high-tech brain diagnostics. Thus, if there is a pathological focus in the white matter, it can be detected at an early stage and promptly prescribed therapy.

Among the diseases that are caused by the defeat of this substance, there are its violations in the hemispheres, pathologies of the capsule, corpus callosum and mixed syndromes. For example, with damage to the back leg, one half of the human body can be paralyzed. This problem may develop with sensory impairment or a visual field defect. Malfunctions of the corpus callosum lead to mental disorders. At the same time, a person ceases to recognize surrounding objects, phenomena, etc., or does not perform purposeful actions. If the focus is bilateral, swallowing and speech disorders may occur.

It is impossible to overestimate the importance of both gray and in the brain. Therefore, the sooner the presence of pathology is detected, the more likely it is that the treatment will be successful.

Referats

Gray and white matter of the brain

The brain is made up of gray and white matter. White matter occupies the entire space between the gray matter of the cerebral cortex and the basal ganglia. The surface of the hemisphere, the pallium, is formed by a uniform layer of gray matter 1.3–4.5 mm thick containing nerve cells.

Let's start with white matter.

There are four parts in white matter:

1) the central substance of the corpus callosum, the internal capsule and long associative fibers.

2) a radiant crown (corona radiata), formed by radiating fibers entering the inner capsule (capsula interna) and leaving it;

3) the area of ​​white matter in the outer parts of the hemisphere - the semi-oval center (centrum semiovale);

4) white matter in the convolutions between the furrows;

The nerve fibers of the white matter are divided into projection, associative and commissural.

The white matter of the hemispheres is formed by nerve fibers that connect the cortex of one gyrus with the cortex of other gyri of its own and opposite hemispheres, as well as with underlying formations.

Two cerebral commissures, commissura anterior and commissura fornicis, are much smaller in size to the olfactory brain rhinencephalon and connect: commissura anterior - olfactory lobes and both parahippocampal gyrus, commissura fornicis - hippocampi.

Most of the commissural fibers are part of the corpus callosum, which connects the parts of both hemispheres belonging to the neencephalon.

The commissural fibers that make up the cerebral commissures, or adhesions, connect not only symmetrical points, but also the cortex belonging to different lobes of opposite hemispheres.

Associative fibers connect different parts of the cortex of the same hemisphere.

Association fibers are divided into short and long.

Short fibers connect adjacent convolutions in the form of arcuate bundles.

Long associative fibers connect areas of the cortex that are more distant from each other.

Projection fibers connect the cerebral cortex with the underlying formations, and through them with the periphery. These fibers are divided into centripetal (ascending, corticopetal, afferent).

On the frontal section of the brain, the internal capsule looks like an oblique white stripe continuing into the brain stem.

In the internal capsule, the anterior leg (crus anterius) is distinguished, - between the caudate nucleus and the anterior half of the inner surface of the lenticular nucleus, the posterior leg (crus posterius), - between the thalamus and the posterior half of the lentiform nucleus and the knee (genu), lying at the inflection point between both parts of the internal capsule. Projection fibers along their length can be divided into the following three systems, starting with the longest:

1. Fibrae thalamocorticalis et corticothalamici - fibers from the thalamus to the cortex and back from the cortex to the thalamus. Conducting excitation towards the cortex, and centrifugal (descending, cortico-fugal, efferent).

2. Tractus corticonuclearis - pathways to the motor nuclei of the cranial nerves. Since all motor fibers are collected in a small space in the internal capsule (the knee and the anterior two-thirds of its posterior leg), if they are damaged in this place, unilateral paralysis of the opposite side of the body is observed.

3. Tractus corticospinalis (pyramidalis) conducts motor volitional impulses to the muscles of the trunk and limbs.

4. Tractus corticopontini - paths from the cerebral cortex to the nuclei of the bridge. Using these pathways, the cerebral cortex has an inhibitory and regulatory effect on the activity of the cerebellum.

Projection fibers in the white matter of the hemisphere closer to the cortex form a radiant crown, and then the main part of them converges into an internal capsule, which is a layer of white matter between the lentiform nucleus (nucleus lentiformis) on the one hand, and the caudate nucleus (nucleus caudatus) and the thalamus ( thalamus) - on the other.

Now consider gray matter.

The surface of the cloak has a very complex pattern, consisting of furrows alternating with each other in various directions and ridges between them, called convolutions, gyri.

Deep permanent furrows are used to divide each hemisphere into large areas called lobes, lobi; the latter, in turn, are divided into lobules and convolutions.

The size and shape of the furrows are subject to significant individual fluctuations, as a result of which not only the brains of different people, but even the hemispheres of the same individual are not quite similar in the furrow pattern.

There are five lobes of the hemisphere: frontal (lobus frontalis), parietal (lobus parietalis), temporal (lobus temporalis), occipital (lobus occipitalis) and a lobule hidden at the bottom of the lateral groove, the so-called island (insula).

The central sulcus (sulcus cenrtalis) begins at the upper edge of the hemisphere and goes forward and downward. The area of ​​the hemisphere located in front of the central sulcus. Refers to the frontal lobe. The part of the brain surface lying behind the central sulcus is the parietal lobe. The posterior border of the parietal lobe is the end of the parietal-occipital sulcus (sulcus parietooccipitalis), located on the hemisphere.

Frontal lobe. In the posterior part of the outer surface of this lobe, the sulcus precentralis runs almost parallel to the direction of the sulcus centralis. Two furrows run from it in the longitudinal direction: sulcus frontalis superior et sulcus frontalis inferior. Due to this, the frontal lobe is divided into four convolutions.

The vertical gyrus, gyrus precentralis, is located between the central and precentral sulci. The upper lateral surface of the hemisphere is delimited into lobes by means of three sulci: the lateral, central, and upper end of the parietal-occipital sulcus.

Lateral groove (sulcus cerebri lateralis) begins on the basal surface of the hemisphere from the lateral fossa and then passes to the upper lateral surface

The lobe consists of a series of convolutions, called lobules in some places, which are limited to the furrows of the cerebral surface.

The horizontal convolutions of the frontal lobe are: the upper frontal (gyrus frontalis superior), the middle frontal (gyrus frontalis medius) and the lower frontal (gyrus frontalis inferior).

The temporal share. The lateral surface of this lobe has three longitudinal convolutions, separated from each other by sulcus temporalis superior and sulcus temporalis inferior. The gyrus temporalis medius extends between the upper and lower temporal sulci. Below it passes gyrus temporalis inferior.

Occipital lobe. The furrows of the lateral surface of this lobe are changeable and unstable. Of these, a transverse sulcus occipitalis transversus is distinguished, which usually connects to the end of the interparietal sulcus.

Parietal lobe. On it, approximately parallel to the central sulcus, is the sulcus postcentralis, which usually merges with the sulcus intraparietalis, which runs in a horizontal direction. Depending on the location of these furrows, the parietal lobe is divided into three convolutions.

The vertical gyrus, gyrus postcentralis, runs behind the central sulcus in the same direction as the precentral gyrus. Above the interparietal sulcus is placed the superior parietal gyrus, or lobule (lobulus parietalis superior), below - lobulus parietalis inferior.

Island. This slice is in the shape of a triangle. The surface of the island is covered with short convolutions.

The lower surface of the hemisphere in that part of it, which lies anterior to the lateral fossa, belongs to the frontal lobe.

On the posterior part of the basal surface of the hemisphere, two furrows are visible: sulcus occipitotemporalis, passing in the direction from the occipital pole to the temporal and limiting the gyrus occipitotemporalis lateralis, and running parallel to it sulcus collateralis. Here, sulcus olfactorius runs parallel to the medial edge of the hemisphere. Parallel to and above this groove, it runs along the medial surface of the sulcus cinguli hemisphere. Between them is gyrus occipitotemporalis medialis.

Medially from the collateral sulcus there are two convolutions: between the posterior part of this sulcus and the sulcus calcarinus lies the gyrus lingualis; between the anterior part of this furrow and the deep sulcus hippocampi lies the gyrus parahippocampalis.

The gyrus adjacent to the brain stem is already on the medial surface of the hemisphere.

Behind the prewedge lies a separate section of the cortex, belonging to the occipital lobe - a wedge (cuneus). The cingulate gyrus (gyrus cinguli) extends between the lingual sulcus and the sulcus of the corpus callosum, which, through the isthmus (isthmus), continues into the parahippocampal gyrus, ending in a hook (uncus). Gyrus cinguli, isthmus and gyrus parahippocampalis together form a vaulted gyrus (gyrus fornicatus), which describes an almost complete circle, open only from below and in front.

On the medial surface of the hemisphere there is a corpus callosum groove (sulcus corpori callosi), which runs directly above the corpus callosum and continues with its posterior end into the deep sulcus hippocampi, which goes forward and downward.

Paracentral lobule (lobulus paracentralis) is a small area above the lingual groove. From the paracentral lobule is a quadrangular surface (the so-called precuneus). It belongs to the parietal lobe. The vaulted gyrus is not related to any of the lobes of the cloak. It belongs to the limbic region. The limbic region is part of the neocortex of the cerebral hemispheres, occupying the cingulate and parahippocampal gyrus; part of the limbic system.

Expanding the edge of the sulcus hippocampi, one can see a narrow jagged gray strip, which is a rudimentary gyrus dentatus gyrus.

Bibliography

1. M.G. Weight gain, N.K. Lysenkov, V.I. Bushkovich. Human anatomy. M., 1985

2. Great medical encyclopedia. v. 11, M., 1979

3. Big medical encyclopedia. v. 6, M., 1977

The brain is made up of gray and white matter. White matter occupies the entire space between the gray matter of the cerebral cortex and the basal ganglia. The surface of the hemisphere, the pallium, is formed by a uniform layer of gray matter 1.3–4.5 mm thick containing nerve cells.

Let's start with white matter.

There are four parts in white matter:

Central substance of the corpus callosum, internal capsule and long associative fibers;

Radiant crown (corona radiata), formed by radially diverging fibers entering the internal capsule (capsula interna) and leaving it;

The area of ​​white matter in the outer parts of the hemisphere is the semi-oval center (centrum semiovale);

White matter in the gyri between the sulci.

The nerve fibers of the white matter are divided into projection, associative and commissural.

The white matter of the hemispheres is formed by nerve fibers that connect the cortex of one gyrus with the cortex of other gyri of its own and opposite hemispheres, as well as with underlying formations.

Two cerebral commissures, commissura anterior and commissura fornicis, are much smaller in size to the olfactory brain rhinencephalon and connect: commissura anterior - olfactory lobes and both parahippocampal gyrus, commissura fornicis - hippocampi.

The commissural fibers that make up the cerebral commissures, or adhesions, connect not only symmetrical points, but also the cortex belonging to different lobes of opposite hemispheres.

Associative fibers connect different parts of the cortex of the same hemisphere.

Association fibers are divided into short and long.

Short fibers connect adjacent convolutions in the form of arcuate bundles.

Long associative fibers connect areas more distant from each other

Projection fibers connect the cerebral cortex with the underlying formations, and through them - with the periphery.

On the frontal section of the brain, the internal capsule looks like an oblique white stripe continuing into the brain stem.

In the internal capsule, the anterior leg (crus anterius) is distinguished - between the caudate nucleus and the anterior half of the inner surface of the lenticular nucleus, and the posterior leg (crus posterius) - between the thalamus and the posterior half of the lentiform nucleus and knee (genu). Projection fibers according to their length can be divided into the following three systems:

Fibrae thalamocorticalis et corticothalamici - fibers from the thalamus to the cortex and back from the cortex to the thalamus; conducting excitation towards the cortex and centrifugal (descending, cortico-fugal, efferent).

Tractus corticonuclearis - pathways to the motor nuclei of the cranial nerves. Since all motor fibers are collected in a small space in the internal capsule (the knee and the anterior two-thirds of its posterior leg), if they are damaged in this place, unilateral paralysis of the opposite side of the body is observed.

Tractus corticospinalis (pyramidalis) conducts motor volitional impulses to the muscles of the trunk and limbs.

Tractus corticopontini - paths from the cerebral cortex to the nuclei of the bridge. Using these pathways, the cerebral cortex has an inhibitory and regulatory effect on the activity of the cerebellum.

Projection fibers in the white matter of the hemisphere closer to the cortex form a radiant crown, and then the main part of them converges into the internal capsule, which is a layer of white matter between the lentiform nucleus (nucleus lentiformis), caudate nucleus (nucleus caudatus) and thalamus (thalamus).

Now consider gray matter.

The surface of the cloak has a very complex pattern, consisting of furrows alternating in different directions and ridges between them, called convolutions.

Deep permanent furrows are used to divide each hemisphere into large areas called lobes; the latter, in turn, are divided into lobules and convolutions.

The size and shape of the furrows are subject to significant individual fluctuations, as a result of which not only the brain of different people, but even the hemispheres of the same individual, are not completely similar in the pattern of furrows.

There are five lobes of the hemisphere: frontal (lobus frontalis), parietal (lobus parietalis), temporal (lobus temporalis), occipital (lobus occipitalis) and a lobule hidden at the bottom of the lateral groove - the so-called island (insula).

The central sulcus (sulcus cenrtalis) begins at the upper edge of the hemisphere and goes forward and downward. The part of the hemisphere located in front of the central sulcus belongs to the frontal lobe. The part of the brain surface lying behind the central sulcus is the parietal lobe. The posterior border of the parietal lobe is the end of the parietal-occipital sulcus (sulcus parietooccipitalis), located on the medial surface of the hemisphere.

Frontal lobe. In the posterior part of the outer surface of this lobe, the sulcus precentralis runs almost parallel to the direction of the sulcus centralis. Two furrows run from it in the longitudinal direction: sulcus frontalis superior et sulcus frontalis inferior. Due to this, the frontal lobe is divided into four convolutions.

The vertical gyrus, gyrus precentralis, is located between the central and precentral sulci. The upper lateral surface of the hemisphere is delimited into lobes by means of three sulci: the lateral, central, and upper end of the parietal-occipital sulcus.

Lateral groove (sulcus cerebri lateralis) begins on the basal surface of the hemisphere from the lateral fossa and then passes to the upper lateral surface

The lobe consists of a series of convolutions, called lobules in some places, which are limited to the furrows of the cerebral surface.

The horizontal convolutions of the frontal lobe are: the upper frontal (gyrus frontalis superior), the middle frontal (gyrus frontalis medius) and the lower frontal (gyrus frontalis inferior).

The temporal share. The lateral surface of this lobe has three longitudinal convolutions, separated from each other by sulcus temporalis superior and sulcus temporalis inferior. The gyrus temporalis medius extends between the upper and lower temporal sulci. Below it passes gyrus temporalis inferior.

Occipital lobe. The furrows of the lateral surface of this lobe are changeable and unstable. Of these, a transverse sulcus occipitalis transversus is distinguished, which usually connects to the end of the interparietal sulcus.

Parietal lobe. On it, approximately parallel to the central sulcus, is the sulcus postcentralis, which usually merges with the sulcus intraparietalis, which runs in a horizontal direction. Depending on the location of these furrows, the parietal lobe is divided into three convolutions.

The vertical gyrus, gyrus postcentralis, runs behind the central sulcus in the same direction as the precentral gyrus. Above the interparietal sulcus is placed the superior parietal gyrus, or lobule (lobulus parietalis superior), below - lobulus parietalis inferior.

Island. This slice is in the shape of a triangle. The surface of the island is covered with short convolutions.

The lower surface of the hemisphere in that part which lies in front of the lateral fossa belongs to the frontal lobe.

On the posterior part of the basal surface of the hemisphere, two furrows are visible: sulcus occipitotemporalis, passing in the direction from the occipital pole to the temporal and limiting the gyrus occipitotemporalis lateralis, and running parallel to it sulcus collateralis. Here, sulcus olfactorius runs parallel to the medial edge of the hemisphere. Parallel to and above this groove, it runs along the medial surface of the sulcus cinguli hemisphere. Between them is gyrus occipitotemporalis medialis.

Medially from the collateral sulcus there are two convolutions: between the posterior part of this sulcus and the sulcus calcarinus lies the gyrus lingualis; between the anterior part of this furrow and the deep sulcus hippocampi lies the gyrus parahippocampalis.

The gyrus adjacent to the brain stem is already on the medial surface of the hemisphere.

Behind the precuneus lies a separate area of ​​the cortex related to the occipital lobe - the wedge (cuneus). The cingulate gyrus (gyrus cinguli) extends between the lingual sulcus and the sulcus of the corpus callosum, which, through the isthmus (isthmus), continues into the parahippocampal gyrus, ending in a hook (uncus). Gyrus cinguli, isthmus and gyrus parahippocampalis together form a vaulted gyrus (gyrus fornicatus), which describes an almost complete circle, open only from below and in front.

On the medial surface of the hemisphere there is a corpus callosum groove (sulcus corpori callosi), which runs directly above the corpus callosum and continues with its posterior end into the deep sulcus hippocampi, which goes forward and downward.

Paracentral lobule (lobulus paracentralis) is a small area above the lingual groove. From the paracentral lobule is a quadrangular surface (the so-called precuneus). It belongs to the parietal lobe. The vaulted gyrus is not related to any of the lobes of the cloak. It belongs to the limbic region. The limbic region is part of the neocortex of the cerebral hemispheres, occupying the cingulate and parahippocampal gyrus; part of the limbic system.

Expanding the edge of the sulcus hippocampi, one can see a narrow jagged gray strip, which is a rudimentary gyrus dentatus gyrus.

The pathways of the central nervous system (tractus sistematis nervosi centralis) are groups of nerve fibers that are characterized by a common structure and functions and connect various parts of the brain and spinal cord.

All nerve fibers of one path start from homogeneous neurocytes and end on neurocytes that perform the same function. In the process of phylogenesis, the senior researcher as a result of the development of the brain, the simple reflex arc underlying the functions of the nervous system becomes more complicated, and in each part of it, instead of a single neurocyte, chains of neurocytes are formed, the axons of which are grouped into pathways. Some pathways of the central nervous system, uniting phylogenetically earlier nuclei located in the brain stem, provide motor reflex responses to external stimuli, maintain muscle tone, body balance, etc. Others transmit impulses to the higher parts of the central nervous system, to the cerebral cortex or from it to the subcortical nuclei and the spinal cord.

Distinguish associative (associative) nerve fibers or bundles of fibers that carry out one-way connections; commissural (commissural) fibers that provide bilateral connections between functionally homogeneous parts of the brain or spinal cord, and projection fibers that connect the cerebral cortex with the underlying parts of the brain and spinal cord. Depending on the size, shape and direction, groups of nerve fibers are called paths, bundles, fibers, spikes, loops and radiances.

Associative are intracortical fibers located within the cerebral cortex, and extracortical short fibers connecting cortical areas of adjacent gyri of the cerebral hemispheres and called arcuate fibers. Long fibers form bundles connecting the lobes within the same hemisphere. These include the upper and lower longitudinal and uncinate bundles, etc. In the spinal cord, associative fibers carry out intersegmental connections and form anterior, lateral, and posterior bundles of their own.

The commissural fibers of the cerebral hemispheres form the anterior commissure, which connects parts of the olfactory brain of the right and left sides; commissure of the fornix connecting the cortex of the medial surfaces of both hemispheres of the cerebrum and the hippocampus; the corpus callosum, the fibers of which form the corpus callosum radiance and connect parts of the neocortex of the right and left hemispheres. Within the diencephalon and midbrain, functionally homogeneous formations of the right and left sides connect the epithalamic (posterior) commissure, the commissure of the leashes, the dorsal and ventral supraoptic commissures. In the spinal cord, the white commissure is formed by fibers passing from one side of the spinal cord to the other (fibers of the spinothalamic bundle, etc.).

Projection fibers in the brain and spinal cord form centripetal (ascending, afferent, sensory) pathways that transmit impulses from receptors that receive information from the external world and the internal environment of the body to the brain, and centrifugal (descending, efferent, motor) pathways that transmit impulses from the structures of the brain to the cells of the motor nuclei of the cranial nerves and the anterior horns of the spinal cord

Afferent pathways, depending on the types of sensitivity, are divided into ways of extero-, proprio- and interoceptive sensitivity (see Autonomic nervous system).

The pathways of exteroceptive sensitivity include the lateral and anterior spinothalamic pathways, the pathways of the sense organs. The lateral spinothalamic pathway (pain and temperature sensitivity) starts from the false unipolar cells of the spinal nodes (the first neuron). Their peripheral processes are part of the spinal nerves and end with receptors in the skin and mucous membranes. The central processes form the posterior roots and go to the spinal cord, ending on the cells of the posterior horns (the second neuron). The processes of the second neurons pass through the white commissure of the spinal cord to the opposite side (form a decussation), are included in the spinothalamic bundle and rise to the medulla oblongata as part of the lateral funiculus. There they are adjacent from the lateral moan to the medial loop, forming the spinal loop, and go through the medulla oblongata, the tegmentum pons and the legs of the brain to the cells of the ventrolateral nucleus of the thalamus (the third neuron). The processes of the cells of the thalamic nucleus make up the thalamocortical bundle passing through the posterior leg of the internal capsule to the cortex of the postcentral gyrus, where the cortical end of the general sensitivity analyzer is located. The anterior spinothalamic pathway is a pathway of touch and pressure, the receptors of which are located in the skin, and the first neurons are in the spinal nodes. Their central sprouts as part of the posterior roots enter the spinal cord and terminate on the cells of the posterior horn (the second neuron). The processes of the second neurons through the white commissure of the spinal cord pass into the anterior funiculus of the opposite side, forming a decussation, join the spinothalamic bundle, in which they go to the medulla oblongata. In the brain, this pathway passes along with the lateral spinal tract as part of the lateral part of the medial loop called the spinal loop. The third neuron of this type is the cells of the ventrolateral nucleus of the thalamus. Part of the fibers that conduct tactile sensitivity does not form a decussation and goes to the brain in the posterior funiculus along with a thin and wedge-shaped bundles. The anterior and lateral spinothalamic tracts are often combined into one spinothalamic bundle, in which the fibers coming from pressure receptors pass in the anterior funiculus closer to the midline. Lateral are the fibers that conduct the sense of touch, and then conduct the sense of pain and temperature. The same group includes the pathways of the sense organs.

Paths of proprioceptive sensitivity (muscle-articular feeling) are directed to the cerebral cortex and to the cerebellum, which regulates the coordination of movements. The pathway of proprioceptive sensitivity, going to the cerebral cortex, received different names in its different parts. In the spinal cord, it passes in the posterior funiculus, where it forms a thin bundle (Gaulle's bundle). which transmits impulses from the lower extremities and the lower half of the trunk, and the laterally located wedge-shaped bundle (Burdach's bundle), which carries impulses from the upper half of the trunk and upper limbs. Both conducting paths end on the cells of the nuclei of the same name in the medulla oblongata, where the second neurons are located. The processes of the second neurons in the medulla oblongata form a decussation of the medial loops, and then within the brainstem they form the bulbo-thalamic pathway, called the medial loop. Part of the fibers of the second neuron, upon exiting the thin and sphenoid nuclei, bends outward and forms external dorsal and ventral arcuate fibers that follow through the lower cerebellar peduncles to the cortex of the cerebellar vermis. The medial loop runs in the tegmentum (posterior part) of the pons and midbrain, its fibers end in the thalamus on the cells of the ventrolateral nucleus of the thalamus (third neuron), the processes of the third neurons (thalamotemperal fibers) pass in the posterior leg of the internal capsule and go to the cerebral cortex in the postcentral gyrus.

Proprioceptive pathways leading to the cerebellum transmit information about the state of the musculoskeletal system, which ensures the regulation of movements and balance of the body. They are represented by the posterior (non-crossed) and anterior (doubly crossed) spinocerebellar tracts.

The central processes of the first neurons of the posterior spinal tract (Flexig's bundle), which lie in the spinal nodes, in the spinal cord approach the cells of the thoracic nucleus (Clark's column), located at the base of the posterior horn (the second neuron). The axons of the second neurons go to the back of the lateral funiculus and rise to the medulla oblongata, from where they go through the inferior cerebellar peduncle to the cells of the cortex of the cerebellar vermis.

The central process of the first neuron of the anterior spinal tract (Govers bundle) ends on the cells of the central intermediate substance adjacent to the thoracic nucleus (second neuron). The processes of the second neurons pass through the white commissure into the anterior part of the lateral funiculus of the opposite side and rise into the brain to the level of the isthmus of the rhomboid brain. In the region of the superior medullary velum, most of the fibers return to their side and go through the superior cerebellar peduncle to the cortex of the cerebellar vermis.

Associative fibers connect the cortex of the vermis and cerebellar hemispheres both through the dentate nucleus with the red nucleus (one of the centers of the extrapyramidal system), and through the thalamus with the cerebral cortex. From the cortex of the cerebellar hemispheres, the impulse is transmitted to the dentate nucleus, from the cells of which dentate-red-nuclear fibers begin, passing through the superior cerebellar peduncle to the red nucleus of the opposite side. In addition to the above connections, the cerebellum has numerous afferent and efferent pathways that connect it with the vestibular nuclei, the reticular formation, the olive, roof and tegmentum of the midbrain, etc. Among them, the afferent pathway that goes to the hemispheres of the cerebellum from the cerebral cortex - the cortico- cerebellopontine path.

Motor P. items are represented by two groups. The first group includes the main motor (pyramidal) path, or pyramidal system. It originates from the giant-pyramidal neurocytes (Betz cells) of the cortex of the precentral gyrus and the pericentral lobule and ends on the cells of the motor nuclei of the cranial nerves (cortical-nuclear tract) and the cells of the anterior horns of the spinal cord (lateral and anterior corticospinal tracts). The second group consists of extrapyramidal, reflex motor pathways included in the extrapyramidal system. The descending pathways descending into the spinal cord include the red nuclear-spinal cord pathway, which originates from the cells of the red nucleus; pre-door-spinal path, starting from the cells of the vestibular nuclei; tegmental-bulbar and tegmental-spinal tracts, coming from the upper and lower colliculus of the roof of the midbrain. All of them end on the cells of the motor nuclei of the cranial nerves or the cells of the anterior horn-spinal cord.

Most of the motor pathways intersect, therefore, if a part of the cortex or the motor center of one side is damaged, there is a violation of the motor function on the other. The lateral corticospinal tract can be traced to the sacral part of the spinal cord and often contains uncrossed fibers. The anterior cortico-spinal tract crosses segmentally and often ends in the thoracic region. That. connections of the motor zone of the cortex are carried out both from the opposite and the same side.

Conducting pathways c.n.s. connect the centers of the brain with each other and with the spinal cord in both directions. So, the textospinal, vestibulospinal, reticulospinal, olivospinal and other descending tracts descend into the spinal cord, and from the spinal cord they rise to the cerebral spinothectal, spinovestibular, spinoreticular, spinolivar and other ascending tracts.

The structure of the human body is complex and unique, this is especially true for the gray and white matter of the brain. However, it was thanks to such features that people were able to achieve existing advantages over other representatives of the animal world. The study of the structure of intracranial structures, their functions and features has not yet been completed. However, knowledge of their location and importance for people's health helps specialists understand the nature of diseases of the nervous system and select optimal treatment regimens.

Each cell of the brain has a body and several processes - a long fiber at the axon and a short one at the dendrites. It is they who determine the color of different parts of the body with their color. So, the gray matter in its structure contains neurons, glial elements and vessels. Its branches are not covered with a shell - from this and a dark shade.

Most of this substance is present in the following departments:

• cortex of the anterior hemispheres;
• thalamus and hypothalamus;
• cerebellum and its nuclei;
• basal ganglia;
• cranial nerves and trunk;
• pillars with spinal horns extending from them.

The entire space along the periphery of the gray structures is occupied by white matter. It contains a huge number of processes of nerve fibers, on top of which the myelin sheath is placed. It also gives a white tint to the fabrics. It is these structures in the central nervous system that form the pathways along which information signals move to dependent organs, or from them back to the central structures.

Main types of white fibers:

• associative - localized in different parts of the spinal nerves;
• ascending - transmit information from internal structures to the cerebral cortex;
• descending - the signal comes from the intracranial formations to the spinal horns, and from there to the internal organs.

It is more convenient to consider how the nervous system is arranged, what is white matter or gray matter, on training models - detailed sections with a color image will clearly demonstrate the features of the location of tissues and structural units.

A bit about gray matter

Gray cells, in contrast to the conductive function of the white matter of the brain, have various tasks:

• physiological - the formation and movement, as well as the receipt and subsequent processing of electrical impulses;
• neurophysiological - speech and vision, thinking and memory with emotional reactions;
• psychological - the formation of the essence of a person's personality, his worldview and motivation with will.

Numerous studies by specialists have made it possible to establish what constitutes the gray matter and white areas of the brain, their role in the central nervous system. However, even today many mysteries remain unsolved.

However, the nuclei of gray matter in the topic of the intracranial hemispheres and those structures in the spinal cord were anatomically structured. In fact, they are the main coordinating center through which human reflexes and higher intellectual activity are formed. For example, if you know where the gray matter of the cortex and its dependent organ are located, you can cause the necessary reaction to the stimulus. This is used by doctors to recover patients after certain neurological diseases.

Of course, what the white matter and subcortical nuclei of the anterior part of the brain consist of will directly determine the speed of transmission of impulses and their processing. This is what makes people different from each other. Therefore, all subcortical lesions in the white matter must be considered separately.

Topography

Fibers of gray and white neurocytes are presented both in the central and in the peripheral part of the nervous regulation. However, if in the spinal cord the gray matter is topographically localized in the middle - it resembles a butterfly in outline that surrounds the spinal canal, then in the cranial region, on the contrary, it covers the main hemispheres. Some of its sections - the core, are located in the depths.

The white matter is localized around the "butterfly" in the spinal part of the brain - nerve fibers surrounded by sheaths, and in the central section - under the cortex, representing separate white clusters and strands.

Highly differentiated gray matter cells form the cerebral cortex - the cloak. They are the human intelligence. An increase in the area of ​​​​the cortex is possible due to the many folds - furrows and convolutions. The thickness of the cloak is ambiguous - more in the region of the central gyrus. Its gradual decrease can be observed towards the spinal cord, the transition to which is designated as the medulla oblongata.

The percentage of white and gray matter in different parts of the brain is ambiguous. As a rule, there are more shellless white clusters. It is customary to distinguish structural departments:

• anterior - large hemispheres, which are covered with a bark of gray matter, inside the nucleus with an environment of white matter;
• middle - a lot of cranial nuclei from dark cells with pathways from white brain fiber;
• intermediate - represented by the thalamus, as well as the hypothalamus, to which impulses travel along many white fibers to the nuclei of the autonomic system located in them;
• cerebellum - resembles the cerebral hemispheres in miniature in structure, since it is possible to distinguish the cortex and subcortex, but not according to functional duties;
• oblong - dominated by gray matter, which is represented by many nuclei and brain centers.

A lot of scientific works are devoted to the study of the representation of one or another part of the body in the brain. However, their research is not completed - nature presents people with new discoveries.

Functions

Due to the complex and unique structure of the nervous system, the substance of the brain is able to perform many functional duties. In fact, it is entrusted with the management of the whole variety of processes occurring inside the body.

So, the functions of the white matter, undoubtedly, are to receive and convey information with the help of nerve impulses - both between separate parts of the brain or spinal cord, and them, as separate structural links of a complex system. In order to present a diagram of the functional responsibilities of white matter, it is necessary to highlight the main fibers:

• associative - responsible for the relationship of different areas of the cortex of one of the hemispheres, for example, short white branches are responsible for the connection between nearby gyri, while long ones are responsible for the interaction of distant areas of the cortex;
• commissural - white fibers connect not only symmetrical zones, but also the cortex in the distant lobes of the hemispheres, which is reflected in the corpus callosum and adhesions, which are located directly between large hemispheric units;
• projection white fibers - are responsible for the quality of the connection of the cerebral cortex with the underlying structural links, as well as the periphery, for example, the delivery of information from motor neurons and back to them, or from sensitive cells.

The anatomical structure and location determines the functions of the gray matter. It is simultaneously able to create and process nerve impulses. Due to them, all internal vital processes are controlled - automatically in the respiratory, cardiovascular, digestive and urinary systems. This is the so-called preservation of the constancy of the internal environment, so that a person as a biological unit can preserve himself as a whole. Whereas the distinctive function of gray matter can be called the development and multiplication of intelligence. The cerebral cortex is present in every living person. However, the level of development of mental abilities is different for everyone. It is the gray cells of the cerebral cortex that are engaged in the acceptance, processing and preservation of information.

Distinctive features

For a clear understanding of what are the important differences between the gray and white matter of the brain, what they are and their functional features, experts have developed criteria. The main ones are presented in the table:

In general, the concept of exclusively gray or white in the overall picture of the brain or spinal cord as such does not exist - these structures of the organ are so closely intertwined anatomically and functionally. Without one, the other cannot exist.

Conventionally, a nerve cell can be imagined as a hotel where people stop to rest and exchange news. This is the gray matter of the brain. However, after that they go further - to visit other interesting places. To do this, they need high-quality high-speed roads - conductive fibers of the white matter.

And if without the dark nuclei of the subcortical structures and the cloak of the cerebral hemispheres, people are not at all able to perform higher nervous actions - memory, thinking, learning, then without full-fledged white matter it is not possible to quickly make decisions or respond to ongoing changes in the surrounding world.

Possible diseases

Any violation of the anatomical integrity of the nerve cell does not go unnoticed. However, the severity of the pathological disorder and its duration is directly affected by the nature of the provoking factor. So, with a deterioration in cerebral blood flow due to atherosclerotic plaque, which leads to posthypoxic changes in the brain - ischemic stroke is characterized by:

• local feeling of numbness;
• partial / complete loss of movement in any part of the body;
• muscle weakness.

If injuries lead to the death of a large area of ​​the cortex, a person completely loses one of his higher nervous functions, becomes an invalid. In the case of a tumor lesion of subcortical structures, disorders in the regulation of structures dependent on them may occur - vegetative deviations, thermoregulation, endocrine disorders.

Of course, diseases of the cortical structures are immediately noticeable. Meanwhile, atrophy of white fibers can be hidden, for example, with discirculatory encephalopathy. Initially, small areas of the brain are affected, which is reflected in the daily activities of a person. Later, the process covers all areas of brain activity - for example, Alzheimer's disease, multiple sclerosis. When conducting magnetic resonance imaging, single foci in the white matter of the frontal lobes can be detected - leukoaraiosis, or their localization in the cerebellum. Then, in addition to intellectual disorders, the patient is characterized by motor failures. The selection of optimal treatment regimens should be done by a neuropathologist, taking into account the anatomical and functional features of the gray / white matter of the brain.

The white matter of the cerebral hemispheres consists of projection, associative and commissural pathways.

I. Projection nerve fibers, neurofibrae projections, connecting the cortex of the hemispheres with the underlying centers and transmitting impulses to the cortex (ascending fibers), and from the cortex (descending fibers), are described in the Brief Review of the Conducting Pathways of the Brain and Spinal Cord.

II. Associative nerve fibers neurofibrae associations(Fig. , ), interconnect different parts of the cortex within the same hemisphere.

Associative pathways of the hemispheres are divided into short and long.

Short associative paths are represented arcuate fibers of the cerebrum, fibrae arcuatae cerebri connecting adjacent convolutions.

Long association paths include the following:

1. superior longitudinal bundle, fasciculus longitudinalis superior connecting the frontal, occipital and parietal lobes;
2. lower longitudinal bundle, fasciculus longitudinalis inferior, connecting the occipital lobe with the temporal;
3. hooked bundle, fasciculus uncinatus, connecting the cortex of the region of the frontal pole with the hook of the temporal lobe and convolutions adjacent to it;
4. belt, cingulum, which connects the region of the olfactory triangle and the subcallosal field with a hook.

III. commissural nerve fibers neurofibrae commissurales, are represented by fibers that connect the same parts of different hemispheres. These include the corpus callosum, anterior commissure, and fornix commissure.

1. corpus callosum, corpus callosum(Fig.,,; see Fig.,), opens in the depth of the longitudinal fissure after removal of the upper part of the cerebral hemispheres. It is a white, elongated and somewhat flattened formation, elongated from front to back, 7–9 cm long.

The corpus callosum is the largest commissure (commissure) of the new sections of the cerebral hemispheres, as it connects the gray matter of the cerebral hemispheres of a later phylogenetic origin - the new cortex (with the exception of the temporal poles).

The anterior corpus callosum folds forward, downward, and then backward to form corpus callosum genu corporis callosi, passing down to beak of the corpus callosum, rostrum corporis callosi. The latter continues in end plate, lamina terminalis.

The middle section of the corpus callosum trunk, truncus corporis callosi, forms a bulge in the longitudinal direction and is its longest part.

Posterior corpus callosum roller, splenium, thickened, freely hanging over the pineal gland and over the plate of the roof of the midbrain.

On the upper surface of the corpus callosum is a thin layer of gray matter - gray cover, indusium griseum, which in some areas forms four small longitudinally extending thickenings in the form stripes, striae, two on each side of the median sulcus. There are two medial longitudinal strips, striae longitudinales mediales, and two lateral longitudinal stripes, striae longitudinales laterales. In the anterior part of the corpus callosum, part of the gray matter (mainly the medial longitudinal strip) passes in the region of the beak into the paraterminal gyrus. The lateral longitudinal strip in the posterior section, bending around the lower surface of the thickening of the corpus callosum, continues into a gray strip - ribbon gyrus, gyrus fasciolaris, and passes to the medial surface of the parahippocampal gyrus as the dentate gyrus.

In addition to the longitudinally running stripes, on the upper surface of the corpus callosum there are a number of transverse stripes, well-defined between the lateral and medial longitudinal stripes.

On a horizontal section of the cerebral hemisphere, carried out at the level of the upper surface of the corpus callosum, the location of the white matter in the form of a semi-oval is clearly visible. On the periphery, the white matter is bordered by a layer of gray matter, which forms the cerebral cortex. The fibers leaving the corpus callosum, diverging radially in the thickness of each hemisphere, form corpus callosum radiatio, radiatio corporis callosi. In it, according to the lobes of the brain, the frontal, parietal, temporal and occipital parts are distinguished. The posterior sections of the radiance, mainly in the region of the occipital part, become thinner and are the upper wall - the roof - of the lower and posterior horns of each lateral ventricle.

The fibers of the corpus callosum, which pass through the beak and knee towards the frontal lobes and behind through the thickening of the corpus callosum towards the occipital and posterior parts of the parietal lobes, are arcuately curved, and their concavities are facing each other. That's why they got the name nuchal forceps [large forceps], forceps occipitalis, And frontal forceps [small forceps], forceps frontalis(see fig.).

2. Anterior commissure, commissura rostralis, is located behind the end plate and is divided into two parts: anterior part, pars anterior connecting the hooks of both temporal lobes, and back, pars posterior, more developed, connecting the parahippocampal gyrus (see Fig.,).

3. Commissure fornix, commissura fornicis, in the form of a triangular plate, is located under the thickening of the corpus callosum between the legs of the arch (Fig.,).

IV. vault, fornix, which is part of the olfactory brain system (see Fig. , , , ), also refers to the white matter of the cerebral hemispheres. This is a strongly curved elongated cord, almost entirely consisting of longitudinal fibers. It distinguishes the body, legs and pillars.

The body of the vault, corpus fornicis, its middle, most thickened part is located under the corpus callosum. On the frontal section of the brain, the body of the vault has the shape of a trihedral prism. Its upper surface fuses with the lower edge of the transparent septum and with the lower surface of the corpus callosum. At the lateral edge of the body of the fornix is ​​the choroid plexus of the lateral ventricle, with the epithelial sheet of which this edge fuses, forming vault tape, tenia fornicis. The latter continues along the pedicle of the fornix into the lower horn of the lateral ventricle. The lateral, obliquely downward surfaces of the body of the fornix freely adjoin the thalamus, their upper surfaces, and the medial upper edges. The rounded lower edge of the body of the fornix lies above the vascular base of the third ventricle.

Posterior fornix - right and left arch legs, crura fornicis, - fuses with the lower surface of the corpus callosum in front of its roller. Behind the thalamus, the fornix peduncles diverge, bend laterally downwards, and each of them enters the lower horn of the corresponding lateral ventricle. Here, each leg of the arch, following the course of the hippocampus to its hook, passes into fimbria hippocampi, fimbria hippocampi, located between the medially lying dentate gyrus and the laterally located hippocampus.

Both legs of the vault from the beginning of their divergence to immersion in the lower horn are connected by a triangular thin plate. The top of this plate is directed anteriorly, the base - backwards. The plate consists of transversely running fibers, well expressed at the base. This disc is called commissures of the fornix, commissura fornicis, its bundles connect the right and left hippocampi.

The anterior sections of the arch diverge somewhat and, forming an arc convex upwards, pass into vault pillars, columnae fornicis. They are located posterior to the anterior commissure and above the anterior sections of the thalamus, so that a semilunar fissure is formed between each column and the thalamus - the interventricular opening. This section of pillars is called the free part of the pillars of the vault.

Each column of the arch, bending behind the anterior commissure, goes down and plunges into the substance of the hypothalamus, closer to the medial surface of the thalamus, i.e., closer to the cavity of the third ventricle. Further, each column enters the corresponding mastoid body. This section of pillars is called the hidden part of the pillar of the vault.

Thus, the fornix extends from the hippocampus to the mammillary bodies.

In the mastoid body, nerve fibers originate, which are directed into the thickness of the thalamus in the form of the main bundle of the mastoid body. One part of the fibers follows the cells of the anterior nuclei of the thalamus, forming mastoid-thalamic bundle, fasciculus mamillothalamicus, , , ):

1. outermost capsule, capsula extrema, located between the bark of the island and the fence;
2. external capsule, capsula externa, is located between the fence and the lenticular core;
3. internal capsule, capsula interna, separates the lenticular nucleus from the caudate nucleus and thalamus.

All the projection fibers of the hemispheres pass through the internal capsule, which form in the white matter of the hemispheres radiant crown, corona radiata.

In the internal capsule there are anterior leg of the internal capsule, crus anterius capsulae internae, knee of the internal capsule, genu capsulae internae, And posterior leg of the internal capsule, crus posterior capsulae internae.

The anterior leg of the internal capsule is formed fronto-bridge way, tractus frontopontinus, which connects the cortex of the frontal lobe with the nuclei of the bridge and is part of cortical-bridge path, tractus corticopontinus. In addition, the anterior leg of the internal capsule contains anterior thalamic radiations, radiationes thalamicae anteriores. In the knee of the internal capsule passes cortical-nuclear pathway, tractus corticonuclearis.

As part of the posterior leg of the internal capsule, 3 parts are distinguished:

1. thalamolentiformis part, pars thalamolentiformis, includes cortico-spinal fibers, fibrae corticospinales, cortical red nuclear fibers, fibrae corticorubrales, cortico-reticular fibers, fibrae corticoreticulares, cortico-thalamic fibers, fibrae corticothalamiae, And thalamo-parietal fibers, fibrae thalamoparietales included in central thalamic radiations, radiationes thalamicae centrales;
2. sublentiform part, pars sublentiformis, contains cortical-tegmental fibers, fibrae corticotectales, temporal-bridge fibers, fibrae temporopontinae, as well as bundles visual and auditory radiance, radiationes optica et acustica;
3. lenticular part, pars retrolentiformis, includes fibers posterior thalamic radiations, radiationes thalamicae posteriores, And parietal-occipital-bridge bundle, fasciculus parietooccipitopontinus.