What are the frontal lobes of the brain responsible for? The structure of the brain - what is each department responsible for? Parietal part of the brain

03.10.2023 Brain Research

On the surface of the superior and lateral parietal lobe there are 3 gyri: 1 vertical - posterior central and 2 horizontal - inferior parietal and superior parietal. The portion of the inferior parietal gyrus, which bends around the posterior part of the lateral sulcus, is called the supramarginal (supramarginal) zone, the part covering the temporal superior gyrus is the nodal zone.

Parietal lobe, functions

The functions of the parietal lobe are combined with the perception and analysis of sensory stimuli. There are also functional centers in the gyri of the parietal lobe.

In the central gyrus at the back, sensitive centers are projected with the projection of the body characteristic of the central anterior gyrus. The face is projected in the lower third of the gyrus, the arm and torso are projected in the middle third, and the leg is projected in the upper third. In the parietal gyrus above there are centers in charge of difficult types of sensitivity: two-dimensional-spatial sense, muscular-articular, the sense of recognizing objects at random, the sense of volume and weight of movement.

From the upper parts of the central posterior gyrus there is a part responsible for the ability to recognize one’s body, the proportions of parts and position.

The first, second, third fields of the postcentral zone occupy the main cortical nucleus of the skin analyzer. Together with field 1 and field 3, it is listed as the primary one, and the second field is the secondary projection area of the skin analyzer. The postcentral part is connected by efferent fibers to the stem and subcortical formations, to the pericentral and other sections of the cerebral cortex. Further, in the parietal lobe there is a cortical section of the sensitive analyzer.

Sensory and primary zones are the zone of the sensory cortex; irritation and destruction of them causes continuous changes in the sensation of the body. They consist of monomodal neurons and form sensations of a single quality. In the primary sensory areas, as a rule, there is a spatial representation of body parts and receptor zones.

Around the primary sensory zones there are also secondary sensory zones, the neurons of which respond to the influence of several stimuli; they are multimodal.

The special sensory part is the parietal cortex of the postcentral gyrus and the part of the para central zone on the medial surface of the hemispheres, and is designated the somatosensory area. Here is the projection of skin sensitivity on the other side of the body from pain, tactile temperature receptors, Interceptive sensitivity and feelings of the musculoskeletal system - from joint, muscle and tendon receptors.

Along with the somatosensory area, the smallest size somatosensory area II is also noted, located at the border of the intersection of the central sulcus with the upper edge of the temporal lobe, in the very depths of the lateral sulcus. The level of dependence of body regions is expressed to a lesser extent.

The parietal lobe is of great importance, like the frontal lobe, in the cerebral hemisphere. In a genetic view, they emphasize the old department, that is, the central gyrus behind, the new one - the superior parietal gyrus and the much newer one - the inferior parietal gyrus.

In the lower part of the parietal lobe there are praxis centers. Praxis is understood as automatic, goal-oriented actions through exercise and repetition that are produced through learning and continuous practice throughout life. Walking, dressing, eating, an element of the mechanics of writing, and various types of work activities are praxis. Praxis is the highest manifestation of what is inherent in man. It is performed as a result of the combined activity of different areas of the cerebral cortex. In the lower sections, the posterior and anterior central gyri, lie the center of the analyzer of Integrative impulses of internal organs and blood vessels. The center has a close connection with the subcortical vegetative bases.

Analysis of signals in the parietal lobe

General

The parietal lobe is a structural formation in the cerebral cortex. Posteriorly it is bounded by the parieto-occipital sulcus and a line that runs from the parieto-occipital sulcus to the superior temporal sulcus. In front it is limited by the central groove.

Functions

The parietal lobe of the brain is responsible for analyzing space. Functional centers are located in the convolutions of this lobe. The central gyrus of this lobe is responsible for the projection of body parts in space, determining their proportions and size.

Primary sensory areas - composed of unimodal neurons and create the sensation of continuous sensation. Around these zones there are secondary sensory zones that respond to stimulation and consist of multimodal neurons.

What fields are included?

Field 3,2,1 - primary somatosensory fields. Located in the postcentral gyrus.
Field 4 - motor area - is located within the boundaries of the precentral gyrus
Field 5 - secondary somatosensory area
Area 6 - secondary motor area
Area 7 is the tertiary motor area. Located in the upper parts of the parietal lobe (between the postcentral gyrus and occipital lobe)
Field 39 - center of the visual analyzer of written speech
Field 40 - motor analyzer of complex skills

Symptoms of the lesion

When different centers of the parietal lobe are affected, different sensations and symptoms arise.

The main lesions of the parietal lobe include:

Semantic aphasia is a defect in simultaneous analysis and speech production. The patient does not understand complex logical and grammatical structures that describe spatial relationships. Examples of questions:
- Vase on a table or table on a vase?
- Who is older - grandma's daughter or daughter's grandmother?
Alexia - reading difficulty. Accompanied by damage to the occipital-parietal junction. This disease affects the “Lexia Center”
Apraxia (spatial) - spatial perception and execution of purposeful movements are impaired. In this disease, the “Praxia Centers” are affected.
Acalculia is the difficulty of doing mental calculations. With such a defeat, the “Account Center” suffers
Astereognosia is a loss of recognition of objects by touch. “Stereognosis centers” are affected

Brain: structure and functions

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

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

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

The cerebral cortex can be divided into four lobes: occipital, parietal, temporal and frontal. In accordance with the first principle - the principle of lateralization - each lobe has its own pair.

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

According to modern science, Alzheimer's disease, one of the most common causes of dementia, is caused by the formation of protein deposits around (and inside) neurons, which prevent these neurons from communicating with other cells and lead to their death. Since scientists have not found effective ways to prevent the formation of protein plaques, the main method of drug control against Alzheimer's disease remains the impact on the work of mediators that ensure communication between neurons. In particular, acetylcholinesterase inhibitors affect acetylcholine, and memantine drugs affect glutamate. Others mistake this behavior for laziness, not suspecting that changes in behavior are a direct consequence of the death of nerve cells in this area of the cerebral cortex.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Brain anatomy

The human brain still remains a mystery to scientists. It is not only one of the most important organs of the human body, but also the most complex and poorly understood. Learn more about the most mysterious organ of the human body by reading this article.

"Brain Introduction" - Cerebral Cortex

In this article, you will learn about the basic components of the brain and how the brain works. This is not at all some kind of in-depth review of all the research into the characteristics of the brain, because such information would fill entire stacks of books. The main purpose of this review is to familiarize you with the main components of the brain and the functions they perform.

The cerebral cortex is the component that makes a human being unique. The cerebral cortex is responsible for all traits unique to humans, including more advanced mental development, speech, consciousness, as well as the ability to think, reason and imagine, since all these processes occur in it.

The cerebral cortex is what we see when we look at the brain. This is the outer part of the brain and can be divided into four lobes. Each bulge on the surface of the brain is known as a gyrus, and each indentation is known as a sulcus.

Four lobes of the brain

The cerebral cortex can be divided into four sections, which are known as lobes (see image above). Each of the lobes, namely the frontal, parietal, occipital and temporal, is responsible for certain functions, ranging from reasoning to auditory perception.

The frontal lobe is located at the front of the brain and is responsible for reasoning, motor skills, cognition and language. At the back of the frontal lobe, next to the central sulcus, lies the motor cortex of the brain. This area receives impulses from different lobes of the brain and uses this information to move parts of the body. Damage to the frontal lobe of the brain can lead to sexual dysfunction, problems with social adaptation, decreased concentration, or contribute to an increased risk of such consequences.
The parietal lobe is located in the middle part of the brain and is responsible for processing tactile and sensory impulses. This includes pressure, touch and pain. The part of the brain known as the somatosensory cortex is located in this lobe and is important for the perception of sensations. Damage to the parietal lobe can lead to problems with verbal memory, impaired gaze control, and problems with speech.
The temporal lobe is located at the bottom of the brain. This lobe also contains the primary auditory cortex, which is necessary for interpreting the sounds and speech we hear. The hippocampus is also located in the temporal lobe - which is why this part of the brain is associated with memory formation. Damage to the temporal lobe can lead to problems with memory, language skills, and speech perception.
The occipital lobe is located at the back of the brain and is responsible for interpreting visual information. The primary visual cortex, which receives and processes information from the retina, is located in the occipital lobe. Damage to this lobe can cause vision problems, such as difficulty recognizing objects, text, and the inability to distinguish colors.

Brain stem

The brainstem consists of the so-called hindbrain and midbrain. The hindbrain, in turn, consists of the medulla oblongata, the pons and the reticular formation.

hindbrain

The hindbrain is the structure that connects the spinal cord to the brain.

The medulla oblongata is located just above the spinal cord and controls many vital functions of the autonomic nervous system, including heart rate, breathing and blood pressure.
The pons connects the medulla oblongata to the cerebellum and helps in coordinating the movements of all parts of the body.
The reticular formation is a neural network located in the medulla oblongata that helps control functions such as sleep and attention.

Midbrain

The midbrain is the smallest region of the brain, which acts as a relay station of sorts for auditory and visual information.

The midbrain controls many important functions, including the visual and auditory systems, and eye movement. Parts of the midbrain called the "red nucleus" and the "substantia nigra" are involved in the control of body movement. The substantia nigra contains a large number of dopamine-producing neurons located in it. Degeneration of neurons in the substantia nigra can lead to Parkinson's disease.

Cerebellum

The cerebellum, also sometimes called the “small brain,” lies on the top of the pons, behind the brain stem. The cerebellum consists of small lobes and receives impulses from the vestibular apparatus, afferent (sensory) nerves, auditory and visual systems. It is involved in movement coordination and is also responsible for memory and learning ability.

Thalamus

Located above the brain stem, the thalamus processes and transmits motor and sensory impulses. Essentially, the thalamus is a relay station that receives sensory impulses and transmits them to the cerebral cortex. The cerebral cortex, in turn, also sends impulses to the thalamus, which then sends them to other systems.

Hypothalamus

The hypothalamus is a group of nuclei located along the base of the brain near the pituitary gland. The hypothalamus connects to many other areas of the brain and is responsible for controlling hunger, thirst, emotions, body temperature regulation, and circadian rhythms. The hypothalamus also controls the pituitary gland by secreting hormones that allow the hypothalamus to control many body functions.

Limbic system

The limbic system consists of four main elements, namely: the amygdala, hippocampus, parts of the limbic cortex and the septal region of the brain. These elements form connections between the limbic system and the hypothalamus, thalamus and cerebral cortex. The hippocampus plays an important role in memory and learning, while the limbic system itself is central to the control of emotional reactions.

Basal ganglia

The basal ganglia are a group of large nuclei that partially surround the thalamus. These nuclei play an important role in the control of movement. The red nucleus and substantia nigra of the midbrain are also connected to the basal ganglia.

What is the brain responsible for?

The brain is the main regulator of all body functions. It belongs to one of the elements of the central nervous system. Its structure and functions have been the main subject of study by physicians for a long time. Thanks to their research, it became known what the brain is responsible for and what parts it consists of. Let's look at all this in more detail.

Brain structure

Before you learn what the brain does, you should familiarize yourself with its structure. It consists of the cerebellum, brainstem and cortex, the latter being formed by the left and right hemispheres. They, in turn, are divided into the following lobes: occipital, temporal, frontal and parietal.

Brain functions

Now let's look at the functions of the brain. Each of its departments is responsible for certain actions and reactions of the body.

Parietal lobe

The parietal lobe allows a person to determine his spatial position. Its main task is to process sensory sensations. It is the parietal lobe that helps a person understand what part of his body was touched, where he is now, what he feels in relation to space, and so on. In addition, the parietal lobe has the following functions:

responsible for the ability to write, read, etc.;
controls human movements;
responsible for the perception of pain, heat and cold.

Frontal lobe

The frontal lobe of the brain has various functions. She is responsible for:

abstract thinking;
attention;
ability to solve problems independently;
desire for initiative;
critical self-assessment;
self-control.

The frontal lobe is also home to the speech center. In addition, it controls urination and the formation of the body. The frontal lobe is responsible for transforming memories into a person's long-term memory. However, its effectiveness decreases if attention is concentrated simultaneously on several objects.

At the top of the frontal lobe is Broca's area. It helps a person find the right words during conversations. Therefore, those people who have suffered an injury to Broca's area often have problems expressing their thoughts, but they clearly understand what others are saying to them.

The frontal lobe is directly involved in thinking about memories, helping a person comprehend them and draw conclusions.

Temporal lobe

The main function of the temporal lobe is to process auditory sensations. It is she who is responsible for converting sounds into words understandable to humans. The temporal lobe contains an area called the Hippocampus. It is responsible for long-term memory and is involved in the development of a number of types of epileptic seizures. Therefore, if a person is diagnosed with temporal lobe epilepsy, it means that the Hippocampus is affected.

Occipital lobe

The occipital lobe contains several neural nuclei, so it is responsible for:

vision. This lobe is responsible for the receptivity and processing of visual information. It also controls the functioning of the eyeballs. Therefore, damage to the occipital lobe causes partial or complete loss of vision.
visual memory. Thanks to the occipital lobe, a person can easily assess the shape of objects and the distance to them. When it is damaged, the functions of binocular vision are disrupted, and as a result, the ability to navigate in an unfamiliar environment is lost.

Brain stem

It should be said right away that the brain stem is formed from the medulla oblongata and midbrain, as well as the pons. In total there are 12 pairs of cranial nerves. They are responsible for:

Another important function of the brain stem is regulating breathing. It is also responsible for the human heartbeat.

Cerebellum

Now let's look at what function belongs to the cerebellum. First of all, it is responsible for balance and coordination of human movement. It also signals the central nervous system about the position of the head and body in space. When it is affected, a person experiences loss of smooth movement of the limbs, slowness of actions and poor speech.

In addition, the cerebellum is responsible for regulating the autonomic functions of the human body. After all, it contains a significant number of synoptic contacts. This part of the brain is also responsible for muscle memory. Therefore, it is so important that there are no violations in its work.

Cortex

The cerebral cortex is divided into several types: new, old and ancient, the last two combine to form the limbic system. Sometimes an interstitial bark is also distinguished, consisting of intermediate ancient and intermediate old bark. The new cortex is represented by convolutions, nerve cells and processes. It also contains several types of neurons.

The cerebral cortex has the following functions:

provides communication between the underlying and overlying brain cells;
corrects dysfunctions of systems that interact with it;
controls consciousness and personality traits.

Of course, the brain has many important functions. Therefore, you should monitor his health and undergo an annual examination. After all, many human diseases are directly related to pathologies that arise in parts of the brain.

Read about the work and purpose of the brain in the articles: How the brain works and What the brain is for. Also, if you are interested in anatomy, read the contents of the article How organs are located.

Functions of the occipital lobe of the brain

The occipital lobe of the brain is primarily responsible for processing and redirecting visual signals. This lobe makes up one section of the cerebral cortex. It receives information from the eyes and optic nerves, and then sends the received signals to either the primary visual cortex or one of two levels of the visual association cortex. The result of this is what is commonly known as visual processing data, essentially the information that the brain uses to interpret and make sense of what a person sees. In healthy people, this lobe functions flawlessly on its own, while problems with it usually lead to serious vision problems. For example, defects in the formation of this lobe can cause blindness or severe visual impairment, and injuries affecting this area can cause a number of sometimes irreversible visual disorders.

Cortex

Although the brain appears as a homogeneous spongy mass, it is composed of a number of intricately interconnected parts. “Cerebral cortex” is the name for the outer layer of the brain, which in humans is the folded and grooved tissue most people identify as the mass of the brain. The cerebral cortex is divided into two hemispheres and also into four lobes. These are the frontal lobe, temporal lobe, parietal lobe and occipital lobe.

The frontal lobe is involved in movement and planning, while the temporal lobe is involved in processing auditory information. The main function of the parietal lobe is the perception of the body, also known as the "somatic sensation" of the body. The occipital lobe, which is located at the back of the cerebral cortex, is associated almost exclusively with vision.

Processing of visual information

Processing of visual information occurs through the coordinated work of the optic nerves that connect to the eyes. They send information to the thalamus, another part of the brain, which then forwards it to the primary visual cortex. Typically, information received by the primary sensory cortex is sent directly to areas next to it called the sensory association cortex. One of the main functions of the occipital lobe is to send information from the primary visual cortex to the visual association cortex. The visual association cortex spans more than one lobe; this means that the occipital lobe is not the only participant in this important function. Together, these brain regions analyze visual information received by the primary visual cortex and store visual memories.

Levels of visual association cortex

There are two levels of visual association cortex. The first level, located around the primary visual cortex, receives information about the movement of objects and color. In addition, it processes signals associated with the perception of shapes. The second level, located in the middle of the parietal lobe, is responsible for the perception of movement and location. Such characteristics as depth of perception are also based here. This level also covers the lower part of the temporal lobe, which is responsible for processing and transmitting three-dimensional shape information.

Consequences of damage

Malfunctions in the functioning of the occipital lobe can cause various visual impairments, most of them quite serious. If the primary visual cortex is completely damaged, the result is usually blindness. The primary visual cortex has a visual field displayed on its surface, and its erasure or deep damage is usually irreversible. Complete damage to the visual cortex often follows severe trauma or occurs as a result of the development of a tumor or other abnormal growth on the surface of the brain. In rare cases, birth defects are the cause.

Focal lesions of the visual association cortex are usually not as severe. Blindness is still possible, but it is less likely to occur. Most often, patients have difficulty recognizing objects. In medical parlance, this problem is called visual agnosia. The patient may be able to pick up a watch and recognize it by touch, but when he looks at a picture of a watch, he will most often be able to describe only its elements, such as the round surface of the dial or the numbers arranged in a circle.

Forecasts

Sometimes normal vision can be restored through treatment or even surgery, but this is not always possible. Much depends on the severity and cause of the injury, as well as the age of the patient. Younger patients, particularly children, often respond better to rehabilitation therapy than adults or those whose brains are no longer growing.

Photo: teens.drugabuse.gov, oerpub.github.io, injurycentral.com

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:

Premotor.
Motor.
Prefrontal dorsolateral.
Prefrontal medial.
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:

The lower third is associated with facial motor skills.
The middle part controls the functions of the hands.
The top third is all about footwork.
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 include the following diseases or conditions:

Neoplasms.
Damages of cerebral vessels.
Pick's pathology.
Gilles de la Tourette's syndrome.
Frontotemporal dementia.
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.
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.

Posterior to the central sulcus is the parietal lobe (lobus parietalis). The posterior border of this lobe is the parieto-occipital sulcus (sulcus parietooccipitalis). This groove is located on the medial surface of the cerebral hemisphere, deeply dissects the upper edge of the hemisphere and passes to its superolateral surface. The border between the parietal and occipital lobes on the dorsolateral surface of the cerebral hemisphere is a conventional line - a downward continuation of the parieto-occipital sulcus. The lower border of the parietal lobe is the lateral sulcus (its posterior branch), which separates this lobe (its anterior sections) from the temporal one.

Within the parietal lobe, the postcentral sulcus (sulcus postcentralis) is distinguished. It starts from the lateral sulcus below and ends above, not reaching the upper edge of the hemisphere. The postcentral sulcus lies behind the central sulcus, almost parallel to it. Between the central and postcentral sulci is the postcentral gyrus (gyrus postcenralis). At the top, it passes to the medial surface of the cerebral hemisphere, where it connects with the precentral gyrus of the frontal lobe, forming together with it the paracentral lobule (lobulus paracentralis). On the superolateral surface of the hemisphere, below, the postcentral gyrus also passes into the precentral gyrus, covering the central sulcus from below. The intraparietal sulcus (sulcus intraparietalis) extends posteriorly from the postcentral sulcus. It is parallel to the upper edge of the hemisphere. Above the intraparietal sulcus there is a group of small convolutions called the superior parietal lobule (lobulus parietalis superior). Below this groove is the lower parietal lobule (lobulus parietalis inferior), within which two gyri are distinguished: supramarginal (gyrus supramarginalis) and angular (gyrus angularis). The supramarginal gyrus covers the end of the lateral sulcus, and the angular gyrus covers the end of the superior temporal sulcus. The lower part of the inferior parietal lobule and the adjacent lower parts of the postcentral gyrus, together with the lower part of the precentral gyrus, hanging over the insular lobe, form the frontoparietal operculum of the insula (operculum frontoparietale).

The parietal lobe includes the posterior central gyrus (primary sensory or projection sensory cortical area) and the association parietal cortex. Located between the tactile and visual cortices, the parietal lobe is important in the perception of three-dimensional space. In the superior parietal lobule, sensory streams from the primary somatosensory cortex are integrated with the influences of higher mental functions (attention, motivation, etc.), especially during voluntary goal-directed movements of the limbs.

The inferior parietal lobe, consisting of an anterior part (gyrus supramarginalis) and a posterior part (gyrus angularis), has even more complex functions. Here, multimodal sensory information (somatic sensations, vision and hearing) is integrated with the processes of perception of internal and external space, language and symbolic thinking, directed attention to external objects and to one's own body.

The parietal lobe occupies the superior lateral surfaces of the hemisphere. From the frontal lobe, the parietal lobe is limited in front and to the side by the central sulcus, from the temporal lobe below - by the lateral sulcus, from the occipital - by an imaginary line running from the upper edge of the parieto-occipital sulcus to the lower edge of the hemisphere.

On the superolateral surface of the parietal lobe there are three gyri: one vertical - posterior central and two horizontal - superior parietal and inferior parietal. The part of the inferior parietal gyrus, which encircles the posterior part of the lateral sulcus, is called the supramarginal (supramarginal) region, and the part surrounding the superior temporal gyrus is the nodal (angular) region.

The parietal lobe, like the frontal lobe, makes up a significant part of the cerebral hemispheres. In phylogenetic terms, it is divided into an old section - the posterior central gyrus, a new one - the superior parietal gyrus and a newer one - the inferior parietal gyrus. The function of the parietal lobe is associated with the perception and analysis of sensory stimuli and spatial orientation. Several functional centers are concentrated in the gyri of the parietal lobe.

In the posterior central gyrus, sensitivity centers are projected with a body projection similar to that in the anterior central gyrus. The face is projected in the lower third of the gyrus, the arm and torso are projected in the middle third, and the leg is projected in the upper third. In the superior parietal gyrus there are centers in charge of complex types of deep sensitivity: muscular-articular, two-dimensional spatial sense, a sense of weight and range of motion, a sense of recognizing objects by touch.

Thus, the cortical part of the sensitive analyzer is localized in the parietal lobe.

Praxis centers are located in the inferior parietal lobe. Praxis refers to purposeful movements that have become automated through repetition and exercise and are developed through training and constant practice throughout an individual’s life. Walking, eating, dressing, the mechanical element of writing, various types of work activities (for example, the movements of a driver while driving a car, mowing, etc.) are praxis. Praxis is the highest manifestation of the human motor function. It is carried out as a result of the combined activity of various areas of the cerebral cortex.

Temporal lobe

The temporal lobe occupies the inferolateral surface of the hemispheres. The temporal lobe is delimited from the frontal and parietal lobes by the lateral sulcus. On the superolateral surface of the temporal lobe there are three gyri - superior, middle and inferior. The superior temporal gyrus is located between the Sylvian and superior temporal fissures, the middle one is between the superior and inferior temporal sulci, and the inferior one is between the inferior temporal sulcus and the transverse medullary fissure. On the lower surface of the temporal lobe, the inferior temporal gyrus, the lateral occipitotemporal gyrus, and the hippocampal gyri (seahorse leg) are distinguished.

The function of the temporal lobe is associated with the perception of auditory, gustatory, olfactory sensations, analysis and synthesis of speech sounds, and memory mechanisms. The main functional center of the superior lateral surface of the temporal lobe is located in the superior temporal gyrus. The auditory, or gnostic, speech center (Wernicke's center) is located here.

In the superior temporal gyrus and on the inner surface of the temporal lobe there is an auditory projection area of the cortex. The olfactory projection area is located in the hippocampal gyrus, especially in its anterior section (the so-called uncus). Next to the olfactory projection zones there are also gustatory ones.

The temporal lobes play an important role in organizing complex mental processes, in particular memory.

Parietal lobe, functions

The functions of the parietal lobe are combined with the perception and analysis of sensory stimuli. There are also functional centers in the gyri of the parietal lobe.

From the upper parts of the central posterior gyrus there is a part responsible for the ability to recognize one’s body, the proportions of parts and position.

Around the primary sensory zones there are also secondary sensory zones, the neurons of which respond to the influence of several stimuli; they are multimodal.

What is the brain responsible for?

Brain structure