What is located in the frontal part of the brain. Symptoms of damage to various lobes of the brain. Characteristics of functional specialization

The frontal lobe occupies the anterior parts of the hemispheres. It is separated from the parietal lobe by the central sulcus, and from the temporal lobe by the lateral sulcus. The frontal lobe has four gyri: one vertical - the precentral and three horizontal - the superior, middle and inferior frontal gyri. The convolutions are separated from each other by grooves.

On the lower surface of the frontal lobes, the rectus and orbital gyri are distinguished. The gyrus recta lies between the inner edge of the hemisphere, the olfactory sulcus and the outer edge of the hemisphere.

In the depths of the olfactory sulcus lie the olfactory bulb and the olfactory tract.

The human frontal lobe makes up 25-28% of the cortex; the average weight of the frontal lobe is 450 g.

The function of the frontal lobes is associated with the organization of voluntary movements, motor mechanisms of speech, regulation of complex forms of behavior, and thinking processes. Several functionally important centers are concentrated in the convolutions of the frontal lobe. The anterior central gyrus is a “representation” of the primary motor zone with a strictly defined projection of body parts. The face is “located” in the lower third of the gyrus, the hand is in the middle third, the leg is in the upper third. The trunk is represented in the posterior parts of the superior frontal gyrus. Thus, a person is projected in the anterior central gyrus upside down and head down (see Fig. 2 B).

The anterior central gyrus, together with the adjacent posterior and parts of the frontal gyri, plays a very important functional role. It is the center of voluntary movements. In the depths of the cortex of the central gyrus, from the so-called pyramidal cells - the central motor neuron a - the main motor path begins - the pyramidal, corticospinal path. The peripheral processes of motor neurons leave the cortex, gather into a single powerful bundle, pass through the central white matter of the hemispheres and enter the brain stem through the internal capsule; at the end of the brainstem they partially decussate (passing from one side to the other) and then descend into the spinal cord. These processes end in the gray matter of the spinal cord. There they come into contact with the peripheral motor neuron and transmit impulses from the central motor neuron to it. Impulses of voluntary movement are transmitted along the pyramidal pathway.

In the posterior sections of the superior frontal gyrus there is also an extrapyramidal center of the cortex, which is closely connected anatomically and functionally with the formations of the so-called extrapyramidal system. The extrapyramidal system is a motor system that assists in voluntary movement. This is a system for “providing” voluntary movements. Being phylogenetically older, the extrapyramidal system in humans provides automatic regulation of “learned” motor acts, maintenance of general muscle tone, readiness of the peripheral motor system to perform movements, and redistribution of muscle tone during movements. In addition, it is involved in maintaining normal posture.

Motor cortex areas are located mainly in the precentral gyrus (areas 4 and 6) and the paracentral lobule on the medial surface of the hemisphere. There are primary and secondary areas - fields 4 and 6. These fields are motor, but according to their characteristics, according to research from the Brain Institute, they are different. In the primary motor cortex(field 4) there are neurons innervating motor neurons of the muscles of the face, trunk and limbs.

Rice. 2. Scheme of self-totopic projection of general sensitivity and motor functions in the cerebral cortex (according to W. Penfield):

A - cortical projection of general sensitivity; B - cortical projection of the motor system. The relative sizes of organs reflect the area of ​​the cerebral cortex from which the corresponding sensations and movements can be caused

It has a clear topographic projection of the muscles of the body (see Fig. 2 B). The main pattern of topographic representation is that the regulation of the activity of muscles that provide the most accurate and varied movements (speech, writing, facial expressions) requires the participation of large areas of the motor cortex. Field 4 is completely occupied by centers of isolated movements, field 6 is only partially occupied (subfield 6a).

The preservation of field 4 turns out to be necessary to obtain movements when both field 4 and field 6 are stimulated. In a newborn, field 4 is almost mature. Irritation of the primary motor cortex causes contraction of the muscles of the opposite side of the body (for the muscles of the head, the contraction can be bilateral). When this cortical zone is damaged, the ability to make fine coordinated movements of the limbs and especially the fingers is lost.

Secondary motor cortex(field 6) has a dominant functional significance in relation to the primary motor cortex, carrying out higher motor functions associated with planning and coordination of voluntary movements. Here, the slowly increasing negative readiness potential, which occurs approximately 1 s before the start of movement, is most recorded. The cortex of area 6 receives the bulk of impulses from the basal ganglia and cerebellum and is involved in the recoding of information about complex movements.

Irritation of the cortex of area 6 causes complex coordinated movements, for example, turning the head, eyes and torso in the opposite direction, cooperative contractions of the flexors or extensors on the opposite side. In the premotor cortex there are motor centers associated with human social functions: the center of written speech in the posterior part of the middle frontal gyrus (field 6), the Broca motor speech center in the posterior part of the inferior frontal gyrus (field 44), providing speech and also a musical motor center (field 45), providing speech tonality and the ability to sing. The lower part of field b (subfield boron), located in the area of ​​the tire, reacts to the electric current with rhythmic chewing movements. Neurons of the motor cortex receive afferent inputs through the thalamus from muscle, joint and skin receptors, from the basal ganglia and cerebellum. The main efferent output of the motor cortex to the stem and spinal motor centers are the pyramidal cells of layer V.

In the posterior part of the middle frontal gyrus there is the frontal oculomotor center, which controls the concomitant, simultaneous rotation of the head and eyes (the center of rotation of the head and eyes in the opposite direction). Irritation of this center causes the head and eyes to turn in the opposite direction. The function of this center is of great importance in the implementation of the so-called orientation reflexes (or “what is this?” reflexes), which are very important for preserving the life of animals.

The frontal cortex of the cerebral hemispheres also takes an active part in the formation of thinking, the organization of purposeful activities, and long-term planning.

Scientists consider the frontal cortex as a set of formations that, from an early age, exhibit pronounced individuality in their anatomical structure. Among these formations there are those that are new, “ human” fields that develop later in life. These include field 46.

Field 46 is a “human field”, because it is an evolutionary neoplasm that differentiates late. Field 46 is the last to mature and reaches 630% of its original size. Because this field is inhibitory, you can notice that children do not control their movements and grab everything that is not lying well. This behavior is typical of monkeys.

General

It is impossible to specifically develop the frontal lobes of the brain in children. There is a misconception in society that physical activity promotes increased blood circulation in the brain, thereby developing all areas of the brain. Physical activity fills the motor centers of the brain, while the rest of the brain ‘ resting‘, because When performing different tasks, the brain uses specific centers, rather than the entire brain.

Based on the above, in order to determine exercises for the development of the frontal lobes, we need to find out what functions the frontal lobes are responsible for, with which we can develop the frontal lobes.

The frontal lobe, like others, consists of and substances.

Location

The frontal lobe is located in the anterior parts of the hemispheres. The frontal lobe is separated from the parietal lobe by the central sulcus, and from the temporal lobe by the lateral sulcus. Anatomically it consists of four convolutions - vertical and three horizontal. The convolutions are separated by grooves. The frontal lobe makes up one third of the mass of the cortex.

Assigned functions

Evolutionarily, it so happened that the active development of the frontal lobes is not associated with mental and intellectual activity. The frontal lobes arose in humans through evolution. The more a person could share food within his community, the more likely the community could survive. In women, the frontal lobes arose for the specific purpose of sharing food. The men got this area as a gift. Without those assigned tasks that lie on the shoulders of women, men began to use the frontal lobes in a variety of ways (thinking, building, etc.) to demonstrate Dominance.

Essentially, the frontal lobes are brake centers. Also, many people ask what the left or right frontal lobe of the brain is responsible for. The question is not posed correctly, because... in the left and right frontal lobes there are corresponding fields that are responsible for specific functions. Roughly speaking, the frontal lobes are responsible for:

• thinking
• coordination of movements
• conscious control of behavior
• memory and speech centers
• display of emotions

What fields are included?

Fields and subfields are responsible for specific functions that are generalized under the frontal lobes. Because The polymorphism of the brain is enormous; the combination of the sizes of different fields makes up a person’s individuality. Why do they say that over time a person changes. Throughout life, neurons die, and the remaining ones form new connections. This introduces an imbalance in the quantitative ratio of connections between different fields that are responsible for different functions.

Not only do different people have different margin sizes, but some people may not have these margins at all. Polymorphism was identified by Soviet researchers S.A. Sarkisov, I.N. Filimonov, Yu.G. Shevchenko. They showed that the individual ways in which the cerebral cortex is structured within one ethnic group are so great that no common features can be seen.

• Field 8 is located in the posterior parts of the middle and superior frontal gyri. Has a center for voluntary eye movements
• Area 9 – dorsolateral prefrontal cortex
• Area 10 – Anterior Prefrontal Cortex
• Field 11 – olfactory area
• Area 12 – control of the basal ganglia
• Field 32 – Receptor area of ​​emotional experiences
• Area 44 – Broca's Center (processing information about the location of the body relative to other bodies)

• Field 45 – music and motor center
• Field 46 – motor analyzer of head and eye rotation
• Field 47 – nuclear zone of singing, speech motor component
  • Subfield 47.1
  • Subfield 47.2
  • Subfield 47.3
  • Subfield 47.4
  • Subfield 47.5

Symptoms of the lesion

Symptoms of the lesion are revealed in such a way that the selected functions are no longer adequately performed. The main thing is not to confuse some symptoms with laziness or imposed thoughts on this matter, although this is part of frontal lobe diseases.

• Uncontrollable grasping reflexes (Schuster reflex)
• Uncontrolled grasping reflexes when the skin of the hand is irritated at the base of the fingers (Yanishevsky-Bekhterev Reflex)
• Extension of the toes due to irritation of the skin of the foot (Hermann's sign)
• Maintaining an awkward arm position (Barre's sign)
• Constantly rubbing your nose (Duff's sign)
• Speech Impairment
• Loss of motivation
• Inability to concentrate
• Memory impairment

The following injuries and illnesses may cause these symptoms:

• Alzheimer's disease
• Frontotemporal dementia
• Traumatic brain injuries
• Strokes
• Oncological diseases

With such diseases and symptoms, a person may not be recognizable. A person may lose motivation, and his sense of defining personal boundaries becomes blurred. Impulsive behavior associated with the satisfaction of biological needs is possible. Because disruption of the frontal lobes (inhibitory) opens the boundaries to biological behavior controlled by the limbic system.

Answers to popular questions

• Where is the speech center in the brain?
  • Located in Broca's center, namely in the posterior part of the inferior frontal gyrus
• Where is the memory center in the brain?
  • Memory can be different (auditory, visual, gustatory, etc.). Depending on which center processes certain sensors, information from this sensor is stored in those centers

Shoshina Vera Nikolaevna

Therapist, education: Northern Medical University. Work experience 10 years.

Articles written

If the brain is the control point of the human body, then the frontal lobes of the brain are a kind of “center of power.” Most scientists and physiologists in the world clearly recognize the “palm” of this part of the brain. They are responsible for many important functions. Any damage to this area leads to serious and often irreversible consequences. It is these areas that are believed to control mental and emotional manifestations.

The most important part is located in front of both hemispheres and is a special formation of the cortex. It borders on the parietal lobe, separated from it by the central groove with both the right and left temporal lobes.

In modern humans, the frontal parts of the cortex are very developed and make up about a third of its total surface. Moreover, their mass reaches half the weight of the entire brain, and this indicates their high significance and importance.

They have special areas called the prefrontal cortex. They have direct connections with different parts of the human limbic system, which gives reason to consider them a part of it, a control department located in the brain.

All three lobes of the cerebral hemispheres (parietal, temporal and frontal) contain associative zones, that is, the main functional areas that, in fact, make a person who he is.

Structurally, the frontal lobes can be divided into the following zones:

1. Premotor.
2. Motor.
3. Prefrontal dorsolateral.
4. Prefrontal medial.
5. Orbitofrontal.

The last three areas are combined into the prefrontal region, which is well developed in all great apes and is especially large in humans. It is this part of the brain that is responsible for a person’s ability to learn and cognition, and forms the characteristics of his behavior and individuality.

Damage to this area as a result of disease, tumor formation or injury provokes the development of frontal lobe syndrome. With it, not only mental functions are disrupted, but also the person’s personality changes.

What are the frontal lobes responsible for?

To understand what the frontal zone is responsible for, it is necessary to identify the correspondence of their individual areas to the controlled parts of the body.

The central anterior gyrus is divided into three parts, each of which is responsible for its own area of ​​the body:

1. The lower third is associated with facial motor skills.
2. The middle part controls the functions of the hands.
3. The top third is all about footwork.
4. The posterior parts of the superior gyrus of the frontal lobe control the patient's body.

This same area is part of the human extrapyramidal system. This is an ancient part of the brain that is responsible for muscle tone and voluntary control of movements, for the ability to fix and maintain a certain body position.

Nearby is the oculomotor center, which controls eye movements and helps to freely navigate and move in space.

The main functions of the frontal lobes are the control of speech and memory, the manifestation of emotions, will, and motivational actions. From a physiological point of view, this area controls urination, coordination of movements, speech, handwriting, controls behavior, regulates motivation, cognitive functions, and socialization.

Symptoms indicating LD damage

Since the frontal part of the brain is responsible for numerous activities, manifestations of deviations can affect both physiological and behavioral functions of a person.

Symptoms are related to the location of the lesion in the frontal lobe. All of them can be divided into manifestations of behavioral disorders from the psyche and disorders of motor and physical functions.

Mental symptoms:

• fast fatiguability;
• worsening mood;
• sudden mood swings from euphoria to the deepest depression, transitions from a good-natured state to pronounced aggression;
• fussiness, loss of control over one’s actions. It is difficult for the patient to concentrate and complete the simplest task;
• distortion of memories;
• disturbances of memory, attention, smell. The patient may not smell or may be haunted by phantom odors. Such signs are especially characteristic of a tumor process in the frontal lobes;
• speech disorders;
• violation of critical perception of one’s own behavior, lack of understanding of the pathology of one’s actions.

Other disorders:

• coordination disorders, movement disorders, balance;
• convulsions, seizures;
• reflexive grasping actions of an obsessive type;
• epileptic seizures.

Signs of pathology depend on which area of ​​the LD is affected and how severely.

Treatment methods for LD injuries

Since there are many reasons for the development of frontal lobe syndrome, treatment is directly related to the elimination of the original disease or disorder. These causes may be the following diseases or conditions:

1. Neoplasms.
2. Damages of cerebral vessels.
3. Pick's pathology.
4. Gilles de la Tourette's syndrome.
5. Frontotemporal dementia.
6. Traumatic brain injury, including that received at birth, when the child’s head passed through the birth canal. Previously, such injuries often occurred when obstetric forceps were applied to the head.
7. Some other diseases.

In cases with tumors, whenever possible, surgery is used to remove the tumor; if this is not possible, then palliative treatment is used to maintain the vital functions of the body.

Specific diseases such as Alzheimer's disease do not yet have effective treatment and drugs that can cope with the disease, however, timely therapy can prolong a person's life as much as possible.

What could be the consequences of LD damage?

If the frontal lobe of the brain, the functions of which actually determine a person’s personality, is affected, then after an illness or serious injury the worst thing that can happen is a complete change in the behavior and the very essence of the patient’s character.

In a number of cases, it is noted that a person became the complete opposite of himself. Sometimes damage to the parts of the brain responsible for controlling behavior, the concept of good and evil, and a sense of responsibility for one’s actions led to the emergence of antisocial personalities and even serial maniacs.

Even if extreme manifestations are excluded, LD lesions lead to extremely serious consequences. If the sensory organs are damaged, the patient may suffer from disorders of vision, hearing, touch, smell, and ceases to orientate normally in space.

In other situations, the patient is deprived of the opportunity to normally assess the situation, be aware of the world around him, learn, and remember. Such a person sometimes cannot take care of himself, so he needs constant supervision and help.

If there are problems with motor functions, it is difficult for the patient to move, navigate in space and take care of himself.

The severity of manifestations can only be reduced by promptly seeking medical help and taking emergency measures to prevent further development of damage to the frontal lobe.

GYLS OF THE FRONTAL LOBE OF THE BRAIN - four gyri: one vertical - precentral (anterior central) and three horizontal - upper, middle and lower, separated from each other by grooves; On the lower surface of the frontal lobe, a straight gyrus is distinguished, lying between the inner edge of the hemisphere, the olfactory sulcus and the outer edge of the hemisphere, and the orbital.

In the anterior central gyrus, motor projections of all parts of the body are represented: in the upper third - the leg, in the middle - and the fingers, in the lower third - the face and. The anterior central gyrus (fields 4 and 6), from the pyramidal cells of layers III and V of which the corticospinal (pyramidal) path begins, is the motor center of voluntary movements, ensures their execution together with the adjacent posterior sections of the horizontal frontal gyri. In the posterior parts of the superior frontal gyrus there is a cortex associated with the extrapyramidal system; in the posterior part of the middle frontal gyrus there is the frontal oculomotor, which controls the simultaneous rotation of the head and eyes in the opposite direction; in the posterior third of the inferior frontal gyrus (fields 44 and 45) there is a speech center (Broca's center), in which the voice and apparatus are represented and which in right-handed people is present only in the left hemisphere, and therefore it is called dominant, in contrast to the right - subdominant hemispheres (see also Motor analyzer, Frontal lobe of the cerebral hemispheres)

Psychomotorics: dictionary-reference book. - M.: VLADOS. V.P. Dudiev. 2008.

See what “GYRILS OF THE FRONTAL LOBE OF THE BRAIN” are in other dictionaries:

Folded elevations of the cerebral cortex, limited by grooves; thanks to the convolutions, the surface of the cerebral cortex increases significantly, the total area of ​​which in an adult is 1200 cm3; in each lobe of the brain...

Lobes of the cerebral hemispheres- The frontal lobe (lobus frontalis) (Fig. 254, 258) contains a number of grooves delimiting the convolutions. The precentral sulcus is located in the frontal plane parallel to the central sulcus and together with it separates the precentral gyrus, in... ... Atlas of Human Anatomy

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cerebral cortex- (cortex cerebri) a plate of gray matter 2-3 mm thick, covering the outside of the hemispheres. The area of ​​the cortex is 1400-1600 cm2, 2/3 of the cortex is located deep in the furrows, and about 1/3 is on the surface. The volume of gray matter is 500 cm3,... ...

cerebral hemispheres- (hemispheria cerebri) the largest parts of the telencephalon; separated from each other by a deep longitudinal gap. Between the cerebellum and the hemispheres there is a transverse fissure. In each hemisphere there is a superior, inferolateral and inferomedial... ... Glossary of terms and concepts on human anatomy

Functional blocks of the brain- General structural and functional model of the brain, the concept of the brain as a material substrate of the psyche, developed by A. R. Luria based on the study of mental disorders in various local lesions of the central nervous system.... ... Wikipedia

- [by name German. psychiatrist K. Brodmann (K. Brodmann, 1868 1918)] areas of the cerebral cortex, named after Brodmann, who described 52 fields that differ in size, shape, structure and location of nerve cells in them and ... ... Psychomotorics: dictionary-reference book

The gyrus, in the posterior third of which is the motor center for speech (Broca's center); (see Convolutions of the frontal lobe of the brain) ... Psychomotorics: dictionary-reference book

CRANIO-CEREBRAL TOPOGRAPHY- CRANIO CEREBRAL TOPOGRAPHY, projection on the surface of the skull of various lobes of the brain, convolutions, sulci, border points between various lobes and convolutions of the brain (temporal, parietal and occipital) and finally the projection of individual centers of the brain.… … Great Medical Encyclopedia

1.Motor center located in the precentral gyrus. (see Fig. 10). In the upper third there are neurons that innervate the leg, in the middle - the arm, in the lower third - the face, tongue, larynx and pharynx. Irritation of this area with a weak electric current leads to contraction of a specific muscle group. When the motor center of the brain is damaged, paresis(weakening of movements) and paralysis(complete lack of movement).

Rice. 10. Superolateral surface of the hemisphere: 1 – inferior temporal gyrus; 2 – middle temporal gyrus; 3 – superior temporal gyrus; 4 – postcentral gyrus; 5 – tegmental part (frontal tegmentum); 6 – precentral gyrus;
7 – inferior frontal gyrus; 8 – lateral groove; 9 – frontal lobe;
10 – precentral sulcus; 11 – middle frontal gyrus; 12 – superior frontal gyrus; 13 – postcentral gyrus; 14 – central groove; 15 – superior parietal lobule; 16 – intraparietal sulcus; 17 – inferior parietal lobule;
18 – transverse occipital groove; 19 – occipital lobe; 20 – parietal lobe;
21 – supramarginal gyrus; 22 – temporal lobe; I – counting center; II – center of the body diagram;
III – sensitive area; IV – motor area; V – center of graph; VI – center of combined rotation of the head and eyes in the opposite direction; VII – center of motor speech; VIII – hearing center; IX – center of stereognosis; X – center of sensory speech; XI – center of praxia; XII – amnestic aphasia; XIII – center of visual gnosis;
XIV – semantic aphasia; XV – lexicon center

2. Center of combined head and eye rotation located in the middle frontal gyrus, is a bilateral center and performs a combined rotation of the head and eyes in the opposite direction. If the center in the right hemisphere is damaged, the head and eyes look to the right side, i.e., in the direction of damage. A patient with such damage cannot turn his head and eyes in the direction opposite to the damaged part.