Learn more about the cerebral hemispheres. forebrain

The functional parts of the brain are the brainstem, cerebellum, and the terminal part, which includes the cerebral hemispheres. The last component is the most voluminous part - it occupies about 80% of the mass of the organ and 2% of the weight of the human body, while up to 25% of all energy produced in the body is spent on its work.

The hemispheres of the brain differ slightly from each other in size, depth of convolutions and the functions that they perform: the left one is responsible for logical and analytical thinking, and the right one for motor skills. At the same time, they are interchangeable - if one of them is damaged, then the other is able to partially take over the performance of its functions.

Studying the brains of famous people, experts noticed that a person’s abilities depend on which of the halves of the final section is more developed. For example, artists and poets most often have the right hemisphere developed, since this part of the brain is responsible for creativity.

The main aspects of the physiology of the cerebral hemispheres, or as they are also called hemispheres, on the example of the development of the brain in a child from the moment of his conception.

The central nervous system begins to develop almost immediately after the fertilization of the egg, and already at 4 weeks after the implantation of the embryo in the uterine mucosa, it represents 3 cerebral vesicles connected in series. The first of them is the rudiment of the anterior part of the brain and, consequently, its cerebral hemispheres, the second is the midbrain, and the last, third forms the rhomboid part of the brain.

Parallel to this process, the origin of the cerebral cortex occurs - at first it looks like a small long plate of gray matter, consisting mainly of an accumulation of neuron bodies.

Next, the physiological maturation of the main parts of the brain occurs: by the 9th week of pregnancy, the anterior part increases and forms 2 cerebral hemispheres, interconnected by a special structure - the corpus callosum. As well as smaller nerve commissures (superior and posterior commissures, fornix of the brain), it consists of a large bundle of processes of nerve cells - axons, located mainly in the transverse direction. This structure subsequently allows you to instantly transfer information from one part of the brain to another.

The rudiment of the cortex covering the white matter of the hemispheres also undergoes changes at this time: there is a gradual build-up of layers and an increase in the coverage area. In this case, the upper cortical layer increases faster than the lower one, due to which folds and furrows appear.

By the age of 6 months of the embryo, for example, the left hemisphere of the brain has all the main primary gyrus: lateral, central, corpus callosum, parietal-occipital and spur, while the pattern of their location is mirrored to the right hemisphere. Then the convolutions of the second row are formed, and at the same time there is an increase in the number of layers of the cerebral cortex.

By the time of birth, the final section and, accordingly, the large hemispheres of the human brain have a familiar look to everyone, and the cortex has all 6 layers. The growth of the number of neurons stops. The increase in the weight of the medulla in the future is the result of the growth of existing nerve cells and the development of glial tissues.

As the child develops, neurons form an even larger network of interneuronal connections. For most people, the development of the brain ends by the age of 18.

The cerebral cortex of an adult, covering the entire surface of the cerebral hemispheres, consists of several functional layers:

molecular;
external granular;
pyramidal;
internal granular;
ganglionic;
multimorphic;
white matter.

The neurons of these structures have a different structure and functional purpose, but at the same time they form the gray matter of the brain, which is an integral part of the cerebral hemispheres. Also, with the help of these functional units, the cerebral cortex carries out all the main manifestations of a person's higher nervous activity - thinking, memorization, emotional state, speech and attention.

The thickness of the cortex is not uniform throughout, for example, it reaches its greatest value in the upper parts of the precentral and postcentral gyrus. At the same time, the pattern of the location of the convolutions is strictly individual - on earth there are no two people with the same brains.

Anatomically, the surface of the cerebral hemispheres is divided into several parts or lobes, limited by the most significant convolutions:

Frontal lobe. Behind it is limited to the central furrow, below - lateral. In the direction forward from the central sulcus and parallel to it, the upper and lower precentral sulci lie. Between them and the central sulcus is the anterior central gyrus. From both precentral sulci, the upper and lower frontal sulci depart at a right angle, limiting the three frontal gyrus - the upper middle and lower.
Parietal lobe. This lobe is bounded in front by the central sulcus, below by the lateral sulcus, and posteriorly by the parietal-occipital and transverse occipital sulci. Parallel to the central sulcus and in front of it is the postcentral sulcus, which divides into the superior and inferior sulci. Between it and the central sulcus is the posterior central gyrus.
Occipital lobe. Furrows and convolutions on the outer surface of the occipital lobe are able to change their direction. The most constant of them is the superior occipital gyrus. On the border of the parietal lobe and the occipital lobe there are several transitional gyri. The first surrounds the lower end, which goes to the outer surface of the hemisphere of the parietal-occipital sulcus. In the posterior part of the occipital lobe there are one or two polar grooves that have a vertical direction and limit the descending occipital gyrus at the occipital pole.
The temporal share. This part of the hemisphere is bounded in front by the lateral sulcus, and in the posterior section by a line connecting the posterior end of the lateral sulcus with the lower end of the transverse occipital sulcus. On the outer surface of the temporal lobe are the upper, middle and lower temporal sulci. The surface of the superior temporal gyrus forms the inferior wall of the lateral sulcus and is divided into two parts: the opercular, covered by the parietal operculum, and the anterior, the insular.
Island. It is located in the depth of the lateral groove.

Thus, it turns out that the cerebral cortex, covering the entire surface of the cerebral hemispheres, is the main element of the central nervous system, which allows you to process and reproduce information received from the environment through the senses: sight, touch, smell, hearing and taste. It also participates in the formation of cortical reflexes, purposeful actions and participates in the formation of human behavioral characteristics.

What are the left and right hemispheres of the brain responsible for?

The entire surface of the forebrain cortex, which includes the terminal section, is covered with furrows and ridges that divide the surface of the cerebral hemispheres into several lobes:

Frontal. It is located in front of the cerebral hemispheres, is responsible for the performance of voluntary movements, speech and mental activity. It also controls thinking and determines human behavior in society.
Parietal. Participates in understanding the spatial orientation of the body, and also analyzes the proportions and size of third-party objects.
Occipital. With its help, the brain processes and analyzes incoming visual information.
Temporal. Serves as an analyzer of taste and auditory sensations, and also participates in the understanding of speech, the formation of emotions and the memorization of incoming data.
Island. Serves as an analyzer of taste sensations.

In the course of research, experts found that the cerebral cortex perceives and reproduces information coming from the sense organs in a mirror way, that is, when a person decides to move his right hand, then at that moment the motor zone of the left hemisphere begins to work and vice versa - if the movement is made by the left hand, then the right hemisphere of the brain works.

The right and left hemispheres of the brain have the same morphological structure, but despite this, they perform different functions in the body.

In short, the work of the left hemisphere is aimed at logical thinking and analytical perception of information, while the right one is a generator of ideas and spatial thinking.

The areas of specialization of both hemispheres are discussed in more detail in the table:

	Left hemisphere	Right hemisphere
No. p / p	The main area of activity of this part of the final department is logic and analytical thinking:	The work of the right hemisphere is aimed at the perception of non-verbal information, that is, coming from the external environment not in words, but in symbols and images:
1	With its help, a person develops his speech, writes, and remembers dates and events from his life.	It is responsible for the spatial position of the body, namely for its location at the moment. This feature allows a person to navigate well in the environment, for example in the forest. Also, people with a developed right hemisphere do not solve puzzles for long and easily cope with mosaics.
2	In this part of the brain, the information received from the sense organs is analytically processed and rational solutions are sought in the current situation.	The right hemisphere determines the creative abilities of the individual, for example, the perception and reproduction of musical compositions and songs, that is, a person who has developed this zone of perception hears false notes when singing or playing a musical instrument.
3	Recognizes only the direct meaning of words, for example, people who have this zone damaged cannot understand the meaning of jokes and proverbs, since they require the formation of a mental causal relationship. At the same time, the data received from the environment are processed sequentially.	With the help of the right hemisphere, a person comprehends the meaning of proverbs, sayings and other information presented in the form of a metaphor. For example, the word “burns” in the poem: “A fire of red mountain ash burns in the garden” should not be taken literally, since in this case the author compared the fruits of mountain ash with the flame of a fire.
4	This part of the brain is the analytical center of the incoming visual information, therefore, people who have developed this hemisphere show abilities for the exact sciences: mathematics or, for example, physics, since they require a logical approach to solving problems.	With the help of the right hemisphere, a person can dream and come up with the development of events in various situations, that is, when he fantasizes with the words: “imagine if ...”, then this particular part of the brain is included in his work at that moment. Also, this feature is used when writing surrealistic paintings, where the rich imagination of the artist is required.
5	Controls and gives signals for purposeful movement of limbs and organs right side body.	The emotional sphere of the psyche, although not a product of the activity of the cerebral cortex, is still more subordinate to the right cerebral hemisphere, since non-verbal perception of information and its spatial processing, which requires good imagination, often plays a fundamental role in the formation of feelings.
6	-	The right hemisphere of the brain is also responsible for the sensory perception of a sexual partner, while the process of copulation is controlled by the left side of the final section.
7	-	The right hemisphere is responsible for the perception of mystical and religious events, for dreams and setting certain values in the life of an individual.
8	-	Controls movements on the left side of the body.
9	-	It is known that the right hemisphere of the brain is able to simultaneously perceive and process a large number of information without resorting to analysis of the situation. For example, with its help, a person recognizes familiar faces and determines the emotional state of the interlocutor by facial expression alone.

Also, the cortex of the left and right hemispheres of the brain is involved in the appearance of conditioned reflexes, a characteristic feature of which is that they are formed throughout a person’s life and are not constant, that is, they can disappear and reappear depending on environmental conditions.

At the same time, the incoming information is processed by all functional centers of the cerebral hemispheres: auditory, speech, motor, visual, which allows the body to respond without resorting to mental activity, that is, at the subconscious level. For this reason, newborn children do not have conditioned reflexes, since they do not have life experience.

The left hemisphere of the brain and related functions

Outwardly, the left side of the brain practically does not differ from the right - for each person, the location of the zones and the number of convolutions are the same on both sides of the organ. But at the same time, it is a mirror image of the right hemisphere.

The left hemisphere of the brain is responsible for the perception of verbal information, that is, data transmitted through speech, writing or text. His motor area is responsible for the correct pronunciation of speech sounds, beautiful handwriting, predisposition to writing and reading. At the same time, a developed temporal zone will testify to a person’s ability to memorize dates, numbers and other written symbols.

Also, in addition to the main functions, the left hemisphere of the brain performs a number of tasks that determine certain character traits:

The ability to think logically leaves its mark on human behavior, so there is an opinion that people with developed logic are selfish. But this is not because such people see benefits in everything, but because their brain is looking for more rational ways to solve the tasks, sometimes to the detriment of others.
Lovingness. People with a developed left hemisphere, due to their perseverance, are able to achieve the object of attraction in various ways, but, unfortunately, after gaining what they want, they quickly cool down - they simply become not interested, because most people are predictable.
Due to their punctuality and logical approach to everything, most "left-brained" people have an innate politeness towards others, although for this they often have to be reminded of certain norms of behavior in childhood.
People with a developed left hemisphere almost always reason logically. For this reason, they cannot accurately interpret the behavior of others, especially when the situation is not mundane.
Since individuals with a developed left hemisphere are consistent in everything, they rarely make syntactic and spelling errors when writing texts. In this regard, their handwriting is distinguished by the correct spelling of letters and numbers.
They learn quickly, as they can concentrate all their attention on one thing.
As a rule, people with a developed left hemisphere are reliable, that is, they can be relied upon in any matter.

If a person exhibits all of the above qualities, then this gives reason to assume that his left hemisphere is more developed compared to the right side of the brain.

The right hemisphere of the brain and its functions

The specialization of the right hemisphere of the brain is intuition and perception of non-verbal information, that is, data expressed in facial expressions, gestures and intonation of the interlocutor.

It is noteworthy that people with a developed right hemisphere are able to show their abilities in certain types of art: painting, modeling, music, poetry. This is due to the fact that they are able to think spatially, without focusing on insignificant events in life. Their imagination is rich, which manifests itself when writing paintings and musical works. They also say about such people: "Soaring in the clouds."

People with a developed right hemisphere also have a number of characteristic features:

They are overly emotional, while their speech is rich in epithets and comparisons. Often such a speaker swallows sounds, trying to make as much sense as possible into the spoken words.
People with a developed right hemisphere are holistic, open, trusting and naive in communicating with others, but at the same time they are easily offended or offended. At the same time, they are not ashamed of their feelings - they can cry or become angry in a matter of minutes.
They act according to their mood.
Right-brained people are able to find non-standard ways of solving problems, this is due to the fact that they consider the whole situation as a whole, without focusing on one thing.

Which half of the brain is dominant

Since the left hemisphere of the brain is responsible for the logic and rational approach in everything, it was previously believed that it is the leading one in the entire central system. However, this is not so: in humans, both hemispheres of the brain are involved in life almost equally, they are simply responsible for different areas of higher mental activity.

It is noteworthy that in childhood, in most people, the right hemisphere is usually larger than the left. For this reason, the world around us is perceived somewhat differently than in the adult state - children are prone to fantasies and the perception of non-verbal information, everything seems interesting and mysterious to them. Also, while fantasizing, they learn to communicate with the environment: they play different situations from life in their minds and draw their own conclusions, that is, they gain experience that is so necessary in an adult state. Subsequently, this information is deposited for the most part in the left hemisphere.

However, over time, when the basic aspects of life are learned, the activity of the right hemisphere fades away and the body prefers the left side of the brain as a store of acquired knowledge. Such disunity of the work of parts of the brain negatively affects the quality of human life: it becomes immune to everything new and remains conservative in its views on the future.

What part of the brain is working at the moment can be determined by doing an elementary test.

Look at the moving image:

If it rotates clockwise, then this means that the left hemisphere of the brain, which is responsible for logic and analysis, is currently active. If it moves in the opposite direction, then this means that the right hemisphere is working, which is responsible for emotions and intuitive perception of information.

However, if you make an effort, then the picture can be made to rotate in any direction: for this, you first need to look at it with a defocused look. See the changes?

Synchronized work of both hemispheres

Despite the fact that the two hemispheres of the telencephalon perceive the world around them differently, it is extremely important for a person that they work harmoniously with each other.

Anatomically, this interaction of the cerebral hemispheres is carried out due to the corpus callosum and other adhesions containing a large number of myelin fibers. They connect symmetrically all the zones of one part of the telencephalon with another, and also determine the coordinated work of asymmetrical areas of different hemispheres, for example, the frontal gyri of the right with the parietal or occipital of the left. At the same time, with the help of special structures of neurons - associative fibers, different parts of one hemisphere are connected.

The human central nervous system has a cross distribution of responsibilities - the right hemisphere controls the left half of the body, and the left - the right, while the cooperation of both halves can be clearly demonstrated by trying to simultaneously raise the arms parallel to the floor at a right angle - if this worked out, then this indicates the interaction of both hemispheres at the moment.

It is known that with the help of the work of the left hemisphere, the world looks simpler, while the right side perceives it as it is. This approach allows a person to find more and more new solutions in difficult situations, without complicating his task.

Since the right hemisphere is responsible for emotional perception, without it, people would remain soulless "machines" capable of adapting the world around them to the needs of their life activity. This, of course, is not correct - after all, a person would not be a person if he did not have, for example, a sense of beauty or compassion for others.

In most people, the left hemisphere dominates, while in childhood it develops through the perception of information by the right part of the brain, which allows you to significantly expand the experience gained and form some of the body's reactions to the world around.

Since the brain is able to perceive and remember incoming information for almost a lifetime, with the exception of cases caused by specific diseases, this allows a person to participate in the development of this organ.

What will give the development of each of the hemispheres

In the beginning, let's summarize: any human activity begins with a comparison of new data with previous experience, that is, the left hemisphere is involved in this process. At the same time, the right side of the brain influences the final decision - it is physically impossible to come up with something new, based only on previous experience.

Such a holistic perception of reality allows you not to get hung up only on generally accepted norms and, accordingly, moves a person’s personal growth forward.

The development of the right hemisphere will help a person to more easily make contact with others, and the left hemisphere will contribute to the correct expression of thoughts. This approach has a beneficial effect on the acquisition of success not only in professional activities, but also in other activities related to communication within society. Therefore, thanks to the coordinated activity of both hemispheres, human life becomes more harmonious.

To develop these abilities, experts recommend doing simple exercises several times a day that activate brain activity:

If a person is not good friends with logic, then he is recommended to engage in mental work as much as possible - to solve crosswords or pans, and also give preference to solving mathematical problems. If it is required to develop creative abilities, then in this case you can try to understand the meaning in fiction or painting.
You can activate the work of one of the hemispheres by increasing the load on the side of the body for which it is responsible: for example, to stimulate the left hemisphere, you need to work with the right side of the body, and vice versa. At the same time, the exercises do not have to be too complicated - just jump on one leg or try to rotate the object with your hand.

Examples of simple physical exercises for the development of brain activity

"Ear-nose"

With your right hand, you need to touch the tip of the nose, and with the left - behind the opposite right ear. Then at the same time we release them, clap our hands and repeat the action, mirroring the position of the hands: with the left we hold on to the tip of the nose, and with the right we hold on to the left ear.

"Ring"

This exercise is familiar to almost everyone since childhood: you need to quickly alternately connect the thumb with the index, middle, ring fingers and little finger into a ring. If everything works out without a hitch, then you can try to do the exercise with 2 hands at the same time.

"Mirror Drawing"

Sit down, put a large sheet of white paper on the table, and a pencil in each hand. Then you need to try to simultaneously draw any geometric shapes - a circle, a square or a triangle. Over time, if everything works out, then you can complicate the task - try to draw more complex images.

It is noteworthy that an integrated approach to improving the activity of the cerebral cortex will help not only improve a person’s communication skills, but also slow down age-related changes in the psyche - as you know, an active lifestyle and mental work allow a person to remain young at heart and preserve his intellectual abilities.

Video: Dominant hemisphere test

Shoshina Vera Nikolaevna

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

Articles written

Scientists consider the human brain and its functions a mystery of science. We already know a lot about him and his work, so we are able to treat numerous diseases that were considered fatal. Knowledge of the structure and functioning of the cerebral hemispheres plays an important role in understanding the functioning of the brain, and also helps to understand the problems that arise with diseases and.

Conditions and pathologies that led to severe consequences and even death are amenable to surgical and conservative treatment, returning people to normal life after serious injuries and complex surgical interventions.

The structure of the cerebral hemispheres

The human spinal cord is connected to the brain and up to the midbrain looks like an integral element. Then it is divided into two symmetrical, but ambiguous halves, which are called "greater hemispheres of the brain."

Both together are called the front. The connecting element between them is the corpus callosum. The part located below is called the “base of the brain”.

Differing from the structure of the organ of other mammals in size, the large hemispheres of Homo sapiens are developed and cover the intermediate and middle ones. In size, only similar formations in dolphins and some species of higher primates can be compared with them.

The structure of tissues includes two types of matter:

The gray that forms the outer layer or cortex of the brain. This substance in the form of subcrustal structures is dispersed over the mass of white.
White, which is the internal mass of the medulla, predominant in volume. It forms pathways.

Organs, their functions and coordinated work of all systems are controlled by the BP cortex. It is the thinnest layer of a few millimeters of gray matter, consisting of the bodies of neurons. The cortex is the main part of the brain. It covers the surface of the anterior and is characterized by a large area due to the fact that the hemispheres have a pronounced folding, which is called furrows and convolutions. The approximate surface occupies from 2000 to 2500 square centimeters.

The structure and features of the cerebral cortex determine our interactivity, that is, the ability to make contact with the environment, evaluate it, and obtain the most important data.

She has a rather complex organization and original structure, structure. It is dotted with deep furrows and folds, which are called convolutions. The deepest of all divide the entire forebrain (each of the hemispheres) into lobes:

Frontal.
Temporal.
Parietal.
Occipital.
Island.

Under the occipital lobes is the cerebellum, or "small brain". It has three pairs of "legs" through which it receives extremely important information from the cortex, spinal cord, brain stem, ganglia and other sources. This is an extremely important part, albeit a small one.

It performs the functions of correcting errors that can creep in with incoming and outgoing signals. It contains up to 10% of the neurons that the human central nervous system has. The so-called granular layer is especially rich in them.

Functions

The main activity of the BP is related to the following most important human functions and qualities:

Thinking.
Memory.
Speech.
Manifestations and personality traits.
Creativity, talents and skills.

The large hemispheres are not the same - they are responsible for different functions. The right is responsible for and everything connected with it. The left hemisphere is associated with the abstract and the ability to speak. So with diseases and injuries of this part of the brain, a person loses coherent speech.

The hemispheres are separated from each other by a longitudinal fissure, in the depths of which is the corpus callosum, which connects them to each other. The transverse divides the occipital lobes from the cerebellum, and it borders on the medulla oblongata, which connects to the spinal cord. The weight of the cerebral hemispheres is from 78 to 90% of the mass of the organ.

The cerebral cortex has layers that form its architectonics:

Molecular.
External granular.
layer of pyramidal neurons.
Internal granular.
Ganglion layer. It is also called the internal pyramidal or Betz cells.
multimorphic cells.

The cortex is a highly organized analyzer that allows you to process information received from the outside through the senses - sight, hearing, touch, smell, taste. It contains more cellular fluid than white matter, and is supplied with a large number of blood vessels. The cerebral cortex is involved in the formation of cortical reflexes.

Furrows and convolutions

The surface of the large brain is covered with the so-called pallium, or cloak. It is he who forms the folds, which are commonly called convolutions and furrows. The pallium is composed of gray and white matter.

The cerebral hemispheres are covered with a recognizable deep folding formed by furrows and convolutions. They give the human brain a characteristic appearance by increasing the area of the cortex. The pattern of convolutions is individual not only for each individual, but even for the hemispheres of one brain.

Each of them has a structure consisting of different types of surfaces:

The upper-lateral surface, having a convex shape and directly adjacent to the inner part of the cranial vault.
The lower one, located in the anterior and middle sections deep at the base of the skull, and in the posterior - on the upper part of the cerebellum.
The medial surface, located towards the gap separating both hemispheres.

Each of the parts of the brain has its own "pattern" of convolutions and furrows.

Furrows are usually divided into three categories:

The first, or permanent, are the main ones. There are 10 of them, they are less susceptible to change than others, appear in the early stages of brain formation and have common features for all people and animals.
The second category, or intermittent furrows. They are folds on the surface of the hemispheres, individual for a particular individual. They may have a different number or even completely absent. The intermittent furrows are deep, but smaller than those of the first category.
The third or intermittent furrows are the furrows. They are usually much smaller and smaller than the previous ones, have various changing outlines, their location is associated with ethnic traits or personal characteristics. The grooves of the third category are not inherited.

The pattern can be compared to fingerprints, as it is individual and never completely identical, even among the closest relatives.

The consequences of damage to the shares of BP

The cerebral cortex of the human brain does not duplicate the structures of the subcortex, so any damage to it entails various disorders. They differ depending on which area is injured. Interestingly, there are no specific control centers for individual muscles in the cortex, but only a general set of “rules” for their work.

Damage to certain parts of the cerebral hemispheres leads to the following consequences:

Frontal - the largest part. The two frontal parts make up half of the entire forebrain. The cortex of this lobe is called associative, because all information comes to this area. It is responsible for speech, behavior, feelings, learning. With serious injuries of this part of the brain, the formation of tumors, hemorrhages in a person, the connections between the type, taste, smell, shape of an object and its name are broken, that is, for example, the patient sees an apple, can smell, touch and eat it, but does not understand what exactly is in his hands. Also in the central front is the motor. Its damage leads to a change in behavior, disorders of coordination and movement. It has been established that congenital underdevelopment of the frontal lobe or its damage in early childhood, especially the area responsible for emotions, leads to the appearance of antisocial personalities and serial killers, dangerous maniacs and just sociopaths, petty domestic tyrants suffering from a lack of empathy. The centers responsible for smell and taste are located on the inner surfaces of the frontal and temporal lobes, so injuries to these parts of the brain often lead to disruption or complete loss of these functions.
The temporal region is responsible for the auditory center. In addition to complete or partial deafness, pathologies in this area can lead to the so-called Wernicke's sensory aphasia or word deafness. The patient is able to hear everything perfectly, but he simply does not understand the words, as if they are talking to him in an unfamiliar foreign language. Such aphasia occurs when the analytical center of speech (Wernicke's center) is damaged.
The parietal part, namely its central posterior gyrus, controls musculoskeletal sensitivity. Therefore, its damage entails the loss of these sensations or their strong dulling. Damage to the anterior part of the crown leads to problems with precise movements, the central part is responsible for basic movements, and the back part is responsible for tactile functions. Injuries or diseases in these areas provoke corresponding health problems.
The occipital lobe has a visual center designed to regulate, recognize and process information from the organs of vision. Any problems in this area affect the quality, and severe injuries can cause blindness - temporary or permanent. The upper part of the occipital region is responsible for visual recognition, so a person with problems in this area cannot recognize faces or perceive the environment.
The insular region is not visible when looking at the surface of the brain. Many scientists do not distinguish it as a separate element of the hemispheres, but consider it part of other lobes. Therefore, the characteristics of pathologies are the same as those of the nearest departments - frontal and temporal.

The structure of the brain gradually reveals all its secrets, allowing scientists to find out the relationship between its individual parts and behavior, character, health and emotions of a person. There is still a lot of unknown in it, but a thorough study allows you to delve into the sources of many diseases that until recently were considered incurable.

With all the similarity of our brain with similar structures of other mammals, the human organ and the cerebral hemispheres are, first of all, a unique creation of nature, which makes us rational people.

Issues for discussion:

1. Functions of the subcortical nuclei of the forebrain.

2. Structure and functions of the limbic system

2. Structure and functions of the cerebral cortex.

3. Sensory and motor areas of the cerebral cortex.

4. Primary, secondary and tertiary fields of the cerebral cortex.

Tasks:

As you study the material, fill in the table:

brain area	Field according to Brodman	Violations arising in the event of damage
primary visual cortex
secondary visual cortex	…
primary auditory cortex
Secondary auditory cortex
Primary skin-kinesthetic cortex
Secondary skin-kinesthetic cortex
primary motor cortex
secondary motor cortex
TPO zone (tertiary cortex)
Precentral frontal area (tertiary cortex)
Postcentral temporo-occipital regions of the brain (tertiary cortex)

Note! The table must be completed by the end of the course

Literature:

1. General course of human and animal physiology. In 2 books. Ed. prof. HELL. Nozdrachev. Book. 1. Physiology of the nervous, muscular and sensory systems. - M .: "Higher School", 1991, pp. 222-235.

2. Physiology h-ka: Compendium. Textbook for higher educational institutions / Ed. Academician of the Russian Academy of Medical Sciences B.I. Tkachenko and prof. V.F. Pyatina, St. Petersburg. – 1996, p. 272-277.

3. Smirnov V.M., Yakovlev V.N. Physiology of the central nervous system: Proc. allowance for students. higher textbook establishments. - M.: Academy, 2002. - p. 181-200.

4. Luria A.R. Fundamentals of neuropsychology. - M., 2003 (see chapter 1).

5. Chomskaya E.D. Neuropsychology. - St. Petersburg: Peter, 2005. - 496 p.

Materials for preparing for the lesson

telencephalon anatomy

The telencephalon develops from the anterior cerebral bladder, consists of highly developed paired parts - the right and left hemispheres and the middle part connecting them.

The hemispheres are separated by a longitudinal fissure, in the depth of which lies a plate of white matter, consisting of fibers connecting the two hemispheres - the corpus callosum. Under the corpus callosum there is an arch, which is two curved fibrous strands, which are interconnected in the middle part, and diverge in front and behind, forming pillars and legs of the arch. In front of the pillars of the vault is the anterior commissure. Between the anterior part of the corpus callosum and the arch is a thin vertical plate of brain tissue - a transparent septum.

The hemisphere is made up of gray and white matter. It distinguishes the largest part, covered with furrows and convolutions, - a cloak formed by gray matter lying on the surface - the bark of the hemispheres; the olfactory brain and accumulations of gray matter inside the hemispheres are the basal nuclei. The last two departments make up the oldest part of the hemisphere in evolutionary development. The cavities of the telencephalon are the lateral ventricles.

In each hemisphere, three surfaces are distinguished: the upper-lateral (superior-lateral) convex, corresponding to the cranial vault, the median (medial) - flat, facing the same surface of the other hemisphere, and the lower - irregular in shape. The surface of the hemisphere has a complex pattern, due to furrows going in different directions and ridges between them - convolutions. The size and shape of the furrows and convolutions are subject to significant individual fluctuations. However, there are several permanent furrows that are clearly expressed in all and appear earlier than others in the process of embryo development.

They are used to divide the hemispheres into large sections called lobes. Each hemisphere is divided into five lobes: the frontal, parietal, occipital, temporal and hidden lobes, or an island located deep in the lateral sulcus. The border between the frontal and parietal lobes is the central sulcus, between the parietal and occipital - parietal-occipital. The temporal lobe is separated from the rest by a lateral groove. On the upper lateral surface of the hemisphere in the frontal lobe, a precentral sulcus is distinguished, which separates the precentral gyrus, and two frontal sulci: superior and inferior, dividing the rest of the frontal lobe into the superior, middle, and inferior frontal gyrus.

In the parietal lobe, there is a postcentral sulcus, which separates the postcentral gyrus, and an intraparietal one, dividing the rest of the parietal lobe into the superior and inferior parietal lobules. In the lower lobule, supramarginal and angular gyrus are distinguished. In the temporal lobe, two parallel grooves - the superior and inferior temporal - divide it into the superior, middle and inferior temporal gyrus. In the region of the occipital lobe, transverse occipital furrows and convolutions are observed. On the medial surface, the sulcus of the corpus callosum and the cingulate are clearly visible, between which is the cingulate gyrus.

Above it, surrounding the central sulcus, lies the paracentral lobule. Between the parietal and occipital lobes is the parietal-occipital sulcus, and behind it is the spur sulcus. The area between them is called the wedge, and the one in front is called the pre-wedge. At the point of transition to the lower (basal) surface of the hemisphere lies the medial occipital-temporal, or lingual, gyrus. On the lower surface, separating the hemisphere from the brain stem, there is a deep hippocampal sulcus (seahorse sulcus), outward from which is the parahippocampal gyrus. Laterally, it is separated by a collateral groove from the lateral occipitotemporal gyrus. The island, located in the depths of the lateral (lateral) furrow, is also covered with furrows and convolutions. The cerebral cortex is a layer of gray matter up to 4 mm thick. It is formed by layers of nerve cells and fibers arranged in a certain order.

Figure: furrows and convolutions of the left hemisphere of the large brain; superolateral surface

The most typically arranged sections of the phylogenetically newer cortex consist of six layers of cells, the old and ancient cortex has fewer layers and is simpler. Different parts of the cortex have a different cellular and fibrous structure. In this regard, there is a doctrine of the cellular structure of the cortex (cytoarchitectonics) and the fibrous structure (myeloarchitectonics) of the cerebral cortex.

The olfactory brain in humans is represented by rudimentary formations, well expressed in animals, and makes up the oldest parts of the cerebral cortex.

The basal ganglia are collections of gray matter within the hemispheres. These include the striatum, consisting of the caudate and lenticular nuclei, interconnected. The lenticular nucleus is divided into two parts: the shell, located on the outside, and the pale ball, lying inside. They are subcortical motor centers.

Outside of the lenticular nucleus is a thin plate of gray matter - a fence, in the anterior part of the temporal lobe lies the amygdala. Between the basal nuclei and the thalamus are layers of white matter, the inner, outer and outermost capsules. Pathways pass through the inner capsule.

Figure: furrows and convolutions of the right hemisphere of the large brain; medial and inferior surfaces.

The lateral ventricles (right and left) are the cavities of the telencephalon, lie below the level of the corpus callosum in both hemispheres and communicate through the interventricular foramina with the third ventricle. They have an irregular shape and consist of anterior, posterior and lower horns and a central part connecting them. The anterior horn lies in the frontal lobe, it continues posteriorly into the central part, which corresponds to the parietal lobe. Behind the central part passes into the posterior and lower horns located in the occipital and temporal lobes. In the lower horn is a roller - the hippocampus (seahorse). From the medial side, the choroid plexus extends into the central part of the lateral ventricles, continuing into the lower horn. The walls of the lateral ventricles are formed by the white matter of the hemispheres and the caudate nuclei. The thalamus adjoins the central part from below.

The white matter of the hemispheres occupies the space between the cortex and the basal ganglia. It consists of a large number of nerve fibers running in different directions. There are three systems of fibers of the hemispheres: associative (associative), connecting parts of the same hemisphere; commissural (commissural), connecting parts of the right and left hemispheres, which include the corpus callosum, anterior commissure and commissure of the fornix in the hemispheres, and projection fibers, or pathways connecting the hemispheres with the underlying parts of the brain and spinal cord.

Section "Anatomy" of the portal http://medicinform.net

Physiology of the telencephalon

The telencephalon, or cerebral hemispheres, which have reached their highest development in man, is rightly considered the most complex and most amazing creation of nature.

The functions of this section of the central nervous system are so different from the functions of the brain stem and spinal cord that they are distinguished into a special chapter of physiology called higher nervous activity. This term was introduced by I.P. Pavlov. The activity of the nervous system, aimed at the unification and regulation of all organs and systems of the body, I.P. Pavlov named lower nervous activity. Under the higher nervous activity, he understood behavior, activity aimed at adapting the body to changing environmental conditions, at balancing with the environment. In the behavior of an animal, in its relationship with the environment, the leading role is played by the telencephalon, the organ of consciousness, memory, and in humans - the organ of mental activity, thinking.

To study the localization (location) of functions in the cerebral cortex, or, in other words, the values of individual cortical zones, various methods are used: partial removal of the cortex, electrical and chemical stimulation, recording of brain biocurrents and the method of conditioned reflexes.

The stimulation method made it possible to establish the following zones in the cortex: motor (motor), sensitive (sensory) and mute, which are now called associative.

Motor (motor) areas of the cortex.

Movements occur when the cortex is stimulated in the region of the precentral gyrus. Electrical stimulation of the upper part of the convolutions causes the movement of the muscles of the legs and torso, the middle part of the arms, and the lower part of the muscles of the face.

The size of the cortical motor zone is not proportional to the mass of the muscles, but to the accuracy of movements. Especially large is the zone that controls the movements of the hand, tongue, and mimic muscles of the face. In layer V of the cortex of the motor zones, giant pyramidal cells (Betz's pyramids) were found, the processes of which descend to the motor neurons of the middle, medulla and spinal cord, which innervate the skeletal muscles.

The path from the cortex to the motor neurons is called the pyramidal pathway. This is the way of voluntary movements. After damage to the motor zone, voluntary movements cannot be carried out.

Irritation of the motor zone is accompanied by movements on the opposite half of the body, which is explained by the intersection of the pyramidal pathways on their way to the motor neurons that innervate the muscles.

Figure: motor homunculus. The projections of human body parts on the area of the cortical end of the motor analyzer are shown.

Sensory areas of the cortex.

Extirpation (eradication) of various parts of the cortex in animals made it possible to establish in general terms the localization of sensory (sensitive) functions. The occipital lobes were associated with vision, the temporal - with hearing.

The area of the cortex where this type of sensitivity is projected is called the primary projection area.

Human skin sensitivity, feelings of touch, pressure, cold and heat are projected into the postcentral gyrus. In its upper part there is a projection of the skin sensitivity of the legs and torso, below - the arms and completely below - the head.

The absolute value of the projection zones of individual skin areas is not the same. So, for example, the projection of the skin of the hand occupies a larger area in the cortex than the projection of the surface of the body.

The magnitude of a cortical projection is proportional to the value of a given receptive surface in behavior. Interestingly, the piglet has a particularly large projection into the cortex of the patch.

Articular-muscular, proprioceptive, sensitivity is projected into the postcentral and precentral gyrus.

The visual cortex is located in the occipital lobe. When it is irritated, visual sensations arise - flashes of light; removing it leads to blindness. Removal of the visual zone on one half of the brain causes blindness on one half of each eye, since each optic nerve divides into two halves at the base of the brain (forms an incomplete decussation), one of them goes to its own half of the brain, and the other to the opposite.

If the outer surface of the occipital lobe is damaged not in the projection, but in the associative visual zone, vision is preserved, but recognition disorder (visual agnosia) occurs. The patient, being literate, cannot read what is written, recognizes a familiar person after he speaks. The ability to see is an innate property, but the ability to recognize objects is developed throughout life. There are cases when, from birth, sight is restored to a blind person already at an older age. For a long time he continues to navigate in the world around him by touch. It takes a long time until he learns to recognize objects with the help of vision.

Figure: sensitive homunculus. The projections of human body parts on the region of the cortical end of the analyzer are shown.

The hearing function is provided by the exact lobes of the cerebral hemispheres. Their irritation causes simple auditory sensations.

Removal of both auditory zones causes deafness, and one-sided removal reduces hearing acuity. If areas of the cortex of the auditory zone are damaged, auditory agnosia may occur: a person hears, but ceases to understand the meaning of words. His native language becomes as incomprehensible to him as a foreign, foreign, unfamiliar one. The disease is called auditory agnosia.

The olfactory cortex is located at the base of the brain, in the region of the parahippocampal gyrus.

The projection of the taste analyzer, apparently, is located in the lower part of the postcentral gyrus, where the sensitivity of the oral cavity and tongue is projected.

limbic system.

In the final brain, there are formations (cingulate gyrus, hippocampus, amygdala, septal region) that make up the limbic system. They are involved in maintaining the constancy of the internal environment of the body, the regulation of autonomic functions and the formation of emotions and motivations. This system is otherwise called the "visceral brain", since this part of the telencephalon can be considered as a cortical representation of interoreceptors. This is where information comes from internal organs. With stomach irritation Bladder evoked potentials occur in the limbic cortex.

Electrical stimulation of various areas of the limbic system causes changes in autonomic functions: blood pressure, respiration, movements of the digestive tract, tone of the uterus and bladder.

The destruction of individual parts of the limbic system leads to a violation of behavior: animals can become calmer or, on the contrary, aggressive, easily giving reactions of rage, sexual behavior changes. The limbic system has extensive connections with all areas of the brain, the reticular formation and the hypothalamus. It provides the highest cortical control of all autonomic functions (cardiovascular, respiratory, digestive, metabolism and energy.

Figure: brain formations related to the limbic system (Papez circle).

1 - olfactory bulb; 2 - olfactory path; 3 - olfactory triangle; 4 - cingulate gyrus; 5 - gray inclusions; 6 - vault; 7 - isthmus of the cingulate gyrus; 8 - end strip; 9 - hippocampal gyrus; 11 - hippocampus; 12 - mastoid body; 13 - amygdala; 14 - hook.

association areas of the cortex.

The projection zones of the cortex occupy a small fraction of the entire surface of the cortex in the human brain. The rest of the surface is occupied by the so-called associative zones. The neurons of these areas are not connected either with the sense organs or with the muscles, they communicate between different areas of the cortex, integrating and combining all the impulses flowing into the cortex into integral acts of learning (reading, speech, writing), logical thinking, memory and providing the possibility of an expedient reaction behavior.

With violations of the associative zones, agnosias appear - the inability to recognize and apraxia - the inability to produce learned movements. For example, stereoagnosia is expressed in the fact that a person cannot find either a key or a box of matches by touch in his pocket, although he immediately recognizes them visually. Above were examples of visual agnosia - the inability to read what is written and auditory - a lack of understanding of the meaning of words.

In case of violation of the associative zones of the cortex, aphasia can occur - loss of speech. Aphasia can be motor and sensory. Motor aphasia occurs when the posterior third of the lower frontal gyrus is damaged on the left, the so-called Broca's center (this center is located only in the left hemisphere). The patient understands speech, but he cannot speak. With sensory aphasia, the defeat of the center of Wernicke in the back of the superior temporal gyrus, the patient does not understand the speech.

With agraphia, a person learns to write, with apraxia - to make learned movements: light a match, fasten a button, sing a melody, etc.

The study of function localization by the method of conditioned reflexes on a living healthy animal allowed I.P. Pavlov to discover the facts on the basis of which he built the theory of dynamic localization of functions in the cortex, then brilliantly confirmed by microelectrode studies of neurons. Conditioned reflexes were developed in dogs, for example, to visual stimuli - light, various shapes - a circle, a triangle, and then the entire occipital, visual, cortical zone was removed. After that, the conditioned reflexes disappeared, but time passed, and the disturbed function was partially restored. This is the phenomenon of compensation, or restoration, of the function of I.P. Pavlov explained by expressing the idea of the existence of the core of the analyzer, located in a certain zone of the cortex, and scattered cells scattered throughout the cortex, in the zones of other analyzers. Due to these preserved scattered elements, the lost function is restored. The dog can distinguish light from darkness, but subtle analysis, the establishment of differences between a circle and a triangle, is inaccessible to it, it is peculiar only to the core of the analyzer.

Microelectrode tapping of potentials from individual cortical neurons confirmed the presence of scattered elements. So, in the motor zone of the cortex, cells were found that give a discharge of impulses to visual, auditory, and skin stimuli, and in the visual zone of the cortex, neurons were found that respond with electrical discharges to tactile, auditory, vestibular, and olfactory stimuli. In addition, neurons were found that respond not only to “their own” stimulus, as they say now, the stimulus of their modality, their quality, but also to one or two strangers. They were named polysensory neurons.

Dynamic localization, i.e., the ability of some zones to be replaced by others, provides the cortex with high reliability.

General course of human and animal physiology in 2 books. Book. 1. Physiology of the nervous, muscular and sensory systems: Proc. for biol. and medical specialist. universities / A.D. Nozdrachev, I.A. Barannikova, A.S. Batuev and others; Ed. HELL. Nozdrachev. - M .: Higher. school, 1991. - 512 p.

The forebrain is the most rostral branch of the nervous system. It consists of (bark) and basal ganglia. The latter, being in the cortex, are located between the frontal parts of the brain and the diencephalon. These nuclear structures include the shell, which together make up the striatum. It got its name due to the alternation of gray matter, consisting of nerve cells, and white. These elements of the brain, together with the pale ball, which is called the pallidum, form the striopallidar system. This system in mammals, including humans, is the main nuclear apparatus and is involved in the processes of motor behavior and other important functions.

The composition of the basal ganglia includes having a very diverse cellular composition. In the pale ball are large and small neurons. The striatum has a similar cellular organization. The neurons of the striopallidar system receive impulses from the cerebral cortex, thalamus, and stem nuclei.

What are the functions of the subcortical nuclei?

The nuclei of the striopallidar system are also involved in motor activity. Irritation of the caudate nucleus causes stereotypical head turns and trembling movements of the arms or forelimbs in animals. In the process of studying, it was found out that it is important in the processes of memorizing movements. The irritating effect on this structure disrupts learning. It has an inhibitory effect on motor activity and its emotional components, for example, on aggressive reactions.

cerebral cortex

The forebrain includes a formation called the cortex. It is considered the youngest formation of the brain. Morphologically, the cortex consists of gray matter that covers the entire brain and has a large area due to numerous folds and convolutions. Gray matter is made up of a huge number of nerve cells. Due to this, the number of synoptic connections is very large; this ensures the processes of storing and processing the information received. Based on the appearance and evolution, ancient, old and new bark are distinguished. During the period of mammalian evolution, the new cortex developed especially rapidly. The ancient bark in its composition has olfactory bulbs and tracts, olfactory tubercles. The composition of the old includes the cingulate gyrus, the amygdala and the gyrus of the hippocampus. The remaining areas belong to the new crust.

The nerve cells of the cerebral cortex are arranged in layers and orderly, forming six layers in their composition:

1st - called molecular, formed by a plexus of nerve fibers and contains a minimum number of nerve cells.

2nd - called external granular. It consists of small neurons of various shapes, similar to grains.

3rd - consists of pyramidal neurons.

4th - internal granular, like the outer layer, consists of small neurons.

5th - contains Betz cells (giant pyramidal cells). The processes of these cells (axons) form a pyramidal tract that reaches the caudal sections and passes into the anterior roots.

6th - multiform, consists of triangular and spindle-shaped neurons.

Although the neural organization of the cortex has much in common, a closer study of it showed differences in the course of the fibers, the size and number of cells, and the branching of their detritus. By studying, a map of the crust was compiled, which includes 11 regions and 52 fields.

What is the forebrain responsible for??

Very often, ancient and old bark are combined. They form the olfactory brain. The forebrain is also responsible for alertness and attention, and is involved in autonomic reactions. The system takes part in instinctive behavior and the formation of emotions. In experiments on animals, with an irritating effect on the old bark, effects associated with the digestive system appear: chewing, swallowing, peristalsis. Also, the irritating effect on the tonsils causes a change in the function of internal organs (kidneys, uterus, bladder). Some areas of the cortex are involved in memory processes.

Together, the hypothalamus, the limbic region and the forebrain (ancient and old cortex), form which maintains homeostasis and ensures the preservation of the species.

The forebrain is the most developed structure in the process of evolution.

It predetermines the inclinations of a person, his orientation, behavior, the formation of a personality.

Location - the brain part of the skull.

The article is intended for a general understanding of the structure and purpose.

General information

Formed from the anterior end of the primary neural tube. In embryogenesis, it is divided into 2 parts, one of which generates the telencephalon, the second - the intermediate.

According to the model of Alexander Luria, it consists of 3 blocks:

Block regulation of brain activity levels. Provides for the implementation of certain activities. Responsible for the emotional reinforcement of activity based on predicting its results (success - failure).
Block for receiving, processing and storing incoming information. Participates in the formation of ideas about the ways of implementing activities.
Block of programming, regulation and control over the organization of mental activity. Compares the result with the original intent.

The forebrain takes part in the work of all blocks. Based on information processing, it controls behavior. Administrator of higher psychological functions: perception, memory, imagination, thinking, speech.

Anatomy

The structure of a living individual is not easy to describe. Especially such a component as the brain. This universe that exists in everyone continues to hide its secrets. But that doesn't mean they shouldn't be dealt with.

Development

The forebrain is formed at 3-4 weeks of prenatal development. By the end of the 4th week of embryogenesis, the terminal and diencephalon, the cavity of the third ventricle, are formed from the anterior cerebral bladder.

It consists of the thalamic and hypothalamic regions, which are located on the sides of the third ventricle between the hemispheres and the midbrain.

The thalamic region unites:

The thalamus is an ovoid structure located deep under the cerebral cortex. The oldest, largest (3-4 cm) formation of the diencephalon;
The epithalamus is located above the thalamus. It is famous for the fact that the epiphysis is located in it. Previously, it was believed that the soul lives here. Yogis associate the pineal gland with the seventh chakra. By awakening the organ, you can open the "third eye", becoming a clairvoyant. The gland is tiny, only 0.2 g. But the benefits to the body are enormous, although it was previously considered a rudiment;
subthalamus - a formation located below the thalamus;
metathalamus - bodies located in the back of the thalamus (previously considered a separate structure). Together with the midbrain, they determine the work of the visual and auditory analyzers;

The hypothalamic region includes:

hypothalamus. Located under the thalamus. It weighs 3-5 g. It consists of specialized groups of neurons. Connected with all departments. Governs the pituitary gland;
the posterior lobe of the pituitary gland - the central organ of the endocrine system weighing 0.5 g. It is located at the base of the skull. The posterior lobe, together with the hypothalamus, form the hypothalamic-pituitary complex that controls the activity of the endocrine glands.

Combines:

hemispheres covered with bark. The bark appeared at the later stages of the development of the animal world. It occupies half the volume of the hemispheres. Its surface may exceed 2000 cm 2 ;
corpus callosum - the nerve tract connecting the hemispheres;
striped body. Located on the side of the thalamus. On the cut, it looks like repeating bands of white and gray matter. Promotes the regulation of movements, motivation of behavior;
olfactory brain. It unites structures that are different in purpose, appearance. Among them are the central section of the olfactory analyzer;

Anatomical features

Intermediate

The thalamus looks like a gray-brown egg. Structural unit - nuclei, which are classified according to functional and compositional features.

The epithalamus consists of several units, the best known of which is the greyish-reddish pineal gland.

The subthalamus is a small area of gray matter nuclei connected to white matter.

The hypothalamus is made up of nuclei. There are about 30 of them. Most are paired. Classified by location.

Posterior pituitary. - formation of a rounded shape, location - pituitary fossa of the Turkish saddle.

Finite

Unites the hemispheres, corpus callosum and striatum. The largest department.

The hemispheres are covered with gray matter 1-5 mm thick. The mass of the hemispheres is about 4/5 of the mass of the brain. The convolutions and sulci greatly increase the area of the cortex, which contains billions of neurons and nerve fibers arranged in a certain order. Under the gray matter lies white - the processes of nerve cells. About 90% of the cortex has a typical six-layer structure, where neurons are connected via synapses to each other.

From the point of view of phylogenesis, the cerebral cortex is divided into 4 types: ancient, old, intermediate, new. The main part of the human cortex is the neocortex.

The corpus callosum is shaped like a broad band. Consists of 200-250 million nerve fibers. The largest structure connecting the hemispheres.

Functions

Mission - the organization of mental activity.

Intermediate

Participates in the coordination of the work of organs, regulation of body movement, maintaining temperature, metabolism, emotional background.

thalamus. The main task is to sort information. It works like a relay - it processes and sends data to the brain from receptors and pathways. The thalamus affects the level of consciousness, attention, sleep, wakefulness. Supports the functioning of speech.

Epithalamus. Interaction with other structures occurs through melatonin, a hormone produced by the pineal gland at night (therefore, it is not recommended to sleep in the light). A derivative of serotonin - the "happiness hormone". Melatonin is a participant in the regulation of circadian rhythms, being a natural hypnotic, it affects memory and cognitive processes. It affects the localization of skin pigments (not to be confused with melanin), puberty, inhibits the growth of a number of cells, including cancer cells. Through connections with the basal ganglia, the epithalamus is involved in the optimization of motor activity, through connections with the limbic system - in the regulation of emotions.

Subthalamus. Controls the body's muscle responses.

Hypothalamus. Forms a functional complex with the pituitary gland, directs its work. The complex controls the endocrine system. Its hormones help to cope with distress, maintain homeostasis.

The hypothalamus contains the thirst and hunger centers. The department coordinates emotions, human behavior, sleep, wakefulness, thermoregulation. Here are found similar in action to opiates, which help to endure pain.

hemispheres

They act in conjunction with subcortical structures and the brain stem. Main destination:

Organization of the interaction of the organism with the environment through its behavior.
Body consolidation.

corpus callosum

The corpus callosum was noticed after operations to dissect it in the treatment of epilepsy. Operations relieved seizures, while changing the personality of a person. It was found that the hemispheres are adapted to work independently. However, for coordination of activities, information exchange between them is necessary. The corpus callosum is the main transmitter of information.

striatum

Reduces muscle tone.
Contributes to the coordination of the functioning of internal organs and behavior.
Participates in the formation of conditioned reflexes.

The olfactory brain combines the centers that control the sense of smell.

The cerebral cortex

Head of mental processes. Manages sensory and motor functions. Consists of 4 layers.

The ancient layer is responsible for elementary responses (for example, aggression) characteristic of humans and animals.

The old layer is involved in the formation of attachment, laying the foundations of altruism. Thanks to the layer, we are happy or angry.

The intermediate layer is a formation of a transitional type, since the modification of old formations into new ones is carried out gradually. Ensures the activity of the new and old bark.

The neocortex concentrates information from subcortical structures and the trunk. Thanks to it, living beings think, talk, remember, create.

5 cerebral lobes

The occipital lobe is the central part of the visual analyzer. Provides visual image recognition.

Parietal lobe:

controls movements;
orients in time and space;
provides perception of information from skin receptors.

Thanks to the temporal lobe, living beings perceive a variety of sounds.

The frontal lobe regulates voluntary processes, movements, motor speech, abstract thinking, writing, self-criticism, and coordinates the work of other areas of the cortex.

The insular lobe is responsible for the formation of consciousness, the formation of an emotional response and the support of homeostasis.

Interaction with other structures

The brain during ontogenesis matures unevenly. At birth, unconditioned reflexes are formed. As individuals mature, conditioned reflexes develop.

The parts of the brain are anatomically and functionally interconnected. The trunk together with the cortex are involved in the preparation and implementation of various forms of behavior.

The interaction of the thalamus, limbic system, hippocampus helps to reproduce the image of events: sounds, smells, place, time, spatial location, emotional coloring. The interconnections of the thalamus with areas of the temporal lobe of the cortex contribute to the recognition of familiar places and objects.

The thalamus, hypothalamus, cortex have mutual connections with the medulla oblongata. Thus, the medulla oblongata contributes to the assessment of receptor activity and the normalization of the activity of the musculoskeletal system.

The cooperation of the reticular formation of the trunk and the cortex causes excitation or inhibition of the latter. The cooperation of the reticular formation of the medulla oblongata and the hypothalamus ensures the work of the vasomotor center.

Having considered the structure and purpose, we have come one step closer to understanding the living essence.