The brain is the main human organ that controls all its vital functions, determines its personality, behavior and consciousness. Its structure is extremely complex and is a combination of billions of neurons grouped into departments, each of which performs its own function. Many years of research have made it possible to learn a lot about this organ.

What parts does the brain consist of?

The human brain is made up of several sections. Each of them performs its function, ensuring the vital activity of the body.

According to the structure, the brain is divided into 5 main sections.

Among them:

• Oblong. This part is a continuation of the spinal cord. It consists of nuclei of gray matter and paths from white. It is this part that determines the connection between the brain and the body.
• Average. It consists of 4 tubercles, two of which are responsible for vision and two for hearing.
• Rear. The hindbrain includes the pons and cerebellum. This is a small department in the back of the head, which weighs within 140 grams. Consists of two hemispheres fastened together.
• Intermediate. Consists of thalamus, hypothalamus.
• Finite. This section forms both hemispheres of the brain, connected by the corpus callosum. The surface is full of convolutions and furrows covered by the cerebral cortex. The hemispheres are divided into lobes: frontal, parietal, temporal and occipital.

The last section occupies more than 80% of the total mass of the organ. Also, the brain can be divided into 3 parts: the cerebellum, the trunk and the cerebral hemispheres.

In this case, the entire brain has a coating in the form of a shell, divided into three components:

• Cobweb (cerebrospinal fluid circulates through it)
• Soft (adjacent to the brain and full of blood vessels)
• Hard (contacts the skull and protects the brain from damage)

All components of the brain are important in the regulation of life and have a specific function. But the activity regulation centers are located in the cerebral cortex.

The human brain consists of many departments, each of which has a complex structure and performs a specific role. The largest of them is the final one, which consists of the cerebral hemispheres. All this is covered with three shells that provide protective and nourishing functions.

Learn about the structure and functions of the brain from the proposed video.

What functions does it perform?

The brain and its cortex perform a number of important functions.

Brain

It is difficult to list all the functions of the brain, because it is an extremely complex organ. This includes all aspects of the life of the human body. However, it is possible to single out the main functions performed by the brain.

The functions of the brain include all the feelings of a person. These are sight, hearing, taste, smell and touch. All of them are performed in the cerebral cortex. It is also responsible for many other aspects of life, including motor function.

In addition, diseases can occur against the background of external infections. The same meningitis that occurs due to infections of pneumococcus, meningococcus and the like. The development of the disease is characterized by pain in the head, fever, pain in the eyes and many other symptoms such as weakness, nausea and drowsiness.

Many diseases that develop in the brain and its cortex have not yet been studied. Therefore, their treatment is hampered by a lack of information. So it is recommended to consult a doctor at the first non-standard symptoms, which will prevent the disease by diagnosing it at an early stage.

Brain located in the medulla of the skull. Its average weight is 1360 g. There are three large sections of the brain: the trunk, the subcortical section, and the cerebral cortex. 12 pairs of cranial nerves emerge from the base of the brain.

1 - upper section of the spinal cord; 2 - medulla oblongata, 3 - bridge, 4 - cerebellum; 5 - midbrain; 6 - quadrigemina; 7 - diencephalon; 8 - the cerebral cortex; 9 - corpus callosum, connecting the right hemisphere with the new one; 10 - optic chiasm; 11 - olfactory bulbs.

Parts of the brain and their functions

Departments of the brain		Department structures	Functions
BRAIN STEM	Hind brain	Medulla Here are the nuclei with outgoing pairs of cranial> nerves: XII - sublingual; XI - additional; X - wandering; IX - glossopharyngeal nerves	Conductor - the connection of the spinal and overlying parts of the brain. Reflex: 1) regulation of the activity of the respiratory, cardiovascular and digestive systems; 2) food reflexes of salivation, chewing, swallowing; 3) protective reflexes: sneezing, blinking, coughing, vomiting;
		Pons contains nuclei: VIII - auditory; VII - facial; VI - outlet; V - trigeminal nerves.	Conductor - contains ascending and descending nerve pathways and nerve fibers connecting the hemispheres of the cerebellum to each other and to the cerebral cortex. reflex - responsible for vestibular and cervical reflexes that regulate muscle tone, incl. mimic muscles.
		Cerebellum The hemispheres of the cerebellum are interconnected and are formed by gray and white matter.	Coordination of voluntary movements and maintaining the position of the body in space. Regulation of muscle tone and balance.
	Reticular formation- a network of nerve fibers that braid the brain stem and diencephalon. It ensures the interaction of the ascending and descending pathways of the brain, the coordination of various body functions and the regulation of the excitability of all parts of the central nervous system.
	midbrain	quadrigemina With nuclei of primary visual and auditory centers. Legs of the brain With nuclei IV - oculomotor III - block nerves.	Conductor. Reflex: 1) orienting reflexes to visual and sound stimuli, which manifest themselves in the rotation of the head and torso; 2) regulation of muscle tone and body posture.
SUBCORT	forebrain	Interbrain: a) thalamus (optic tubercle) with nuclei ll -th pair of optic nerves;	Collection and evaluation of all incoming information from the senses. Isolation and transmission to the cerebral cortex of the most important information. regulation of emotional behavior.
		b) hypothalamus.	The highest subcortical center of the autonomic nervous system and all vital body functions. Ensuring the constancy of the internal environment and metabolic processes of the body. Regulation of motivated behavior and provision of protective reactions (thirst, hunger, satiety, fear, rage, pleasure and displeasure). Participation in the change of sleep and wakefulness.
		Basal ganglia (subcortical nuclei)	Role in the regulation and coordination of motor activity (together with the thalamus and cerebellum). Participation in the creation and memorization of programs of purposeful movements, learning and memory.
CORK OF GREAT HEMISPHERES		Ancient and old bark (olfactory and visceral brain)Contains nuclei of the 1st pair of olfactory nerves.	The ancient and old cortex, together with some subcortical structures, formslimbic system, which: 1) is responsible for innate behavioral acts and the formation of emotions; 2) provides homeostasis and control of reactions aimed at self-preservation and preservation of the species: 3 affects the regulation of vegetative functions.
		New bark	1) Carries out higher nervous activity, is responsible for complex conscious behavior and thinking. The development of morality, will, intelligence, are associated with the activity of the cortex. 2) Carries out the perception, evaluation and processing of all incoming information from the senses. 3) Coordinates the activity of all body systems. 4) Provides interaction of the organism with the external environment.

The cerebral cortex

The cerebral cortex- phylogenetically the youngest formation of the brain. Due to the furrows, the total surface area of ​​the cortex of an adult is 1700-2000 cm2. In the cortex, there are from 12 to 18 billion nerve cells, which are located in several layers. The cortex is a layer of gray matter 1.5-4 mm thick.

The figure below shows the functional areas and lobes of the cerebral cortex.

Location of gray and white matter	Lobes of the hemispheres	Hemispheric zones
The cortex is gray matter, the white matter is under the crust, in the white matter there are accumulations of gray matter in the form of nuclei			speech centers
	Parietal	Musculoskeletal zone	Movement control, the ability to distinguish irritations
	temporal	Hearing area	Arcs of reflexes distinguishing sound stimuli
		Taste and olfactory zones	Reflexes of discrimination of tastes and smells
	Occipital	visual area	Distinguishing visual stimuli

Sensory and motor areas of the cerebral cortex

Left hemisphere of the brain	Right hemisphere of the brain
The left hemisphere ("thinking", logical) - - is responsible for the regulation of speech activity, oral speech, writing, counting and logical thinking. Dominant in right-handers.	The right hemisphere ("artistic", emotional) - - is involved in the recognition of visual, musical images, the shape and structure of objects, in conscious orientation in space.
Cross section of the left hemisphere through sensory centers Representation of the body in the sensitive zone of the cerebral cortex. The sensitive area of ​​each hemisphere receives information from the muscles, skin and internal organs of the opposite side of the body.	Cross section of the right hemisphere through the motor centers Representation of the body in the motor area of ​​the cerebral cortex. Each section of the motor zone controls the movements of a particular muscle.

_______________

The source of information:

Biology in tables and diagrams. / Edition 2e, - St. Petersburg: 2004.

Rezanova E.A. Human biology. In tables and diagrams./ M.: 2008.

16. The structure and work of the heart.

20. Anatomy and physiology of the lungs. The mechanism of gas exchange, its violations.

21. The concept of digestion. The structure and functions of the digestive organs.

22. Liver, its structure and functions.

27. The system of excretory organs, its meaning, structure and functions

29. Physiological properties of nervous tissue. The concept of excitability, conductivity and lability.

30. The main processes in the central nervous system, their coordination and age-related features.

32. The phenomenon of the dominant, its significance in the learning process

33. Reflex principle of the nervous system. The concept of reflex, reflex arc, reflex ring.

36. Dynamic stereotype, its role in the learning process

37. Inhibition of conditioned reflexes, its types and age characteristics.

38. External inhibition, its meaning and types.

39. Types of internal inhibition, their role in the learning process.

40. Processes of excitation and inhibition in the central nervous system, their interaction.

41. General concept of analyzers (sensor systems), their types, anatomical and physiological features.

42. Visual analyzer, its structure and functions. Prevention of visual impairment.

43. Auditory analyzer, its structure and functions. Prevention of hearing loss

44. Cerebral hemispheres, their structure, role, functional asymmetry.

45. The cerebral cortex, its structure and significance.

46. ​​Hypothalamo-pituitary-adrenal system, its role.

1. Hygienic requirements for the conditions of schoolchildren's education (the role of external environmental factors of the class)

2. Optimal dimensions of the classroom, their justification.

3. The microclimate of the class, its parameters, methods for their determination.

4. Lighting of the workplace, its types. Hygienic requirements for any kind of lighting.

5. Hygienic requirements for school furniture. Part Parameters

6. Physiological and hygienic requirements for the organization of the educational process.

7. Hygienic assessment of the school regime and the schedule of lessons in the classroom.

8. The maximum allowable weekly study load for schoolchildren, depending on age.

9. Dynamics of students' working capacity during the lesson, school day, school week, school year.

10. Factors affecting the performance of schoolchildren.

11. The role of organizing active recreation for students during breaks.

20. Calorie content of the diet, its calculation.

Calorie Formula: Basal Metabolism

Daily calorie intake for a woman: an example of calculating oo

Daily calorie intake for a man: an example of calculating oo

45. The cerebral cortex, its structure and significance.

The cerebral cortex- the structure of the brain, a layer of gray matter 1.3-4.5 mm thick, located along the periphery of the cerebral hemispheres, and covering them.

The cerebral cortex plays a very important role in the implementation of higher nervous (mental) activity.

In humans, the cortex makes up an average of 44% of the volume of the entire hemisphere as a whole.

The cerebral cortex covers the surface of the hemispheres and forms a large number of furrows of different depth and length. Between the furrows are located various sizes of the gyrus of the large brain.

In each hemisphere, the following surfaces are distinguished:

convex upper lateral surface adjacent to the inner surface of the bones of the cranial vault

bottom surface, the anterior and middle sections of which are located on the inner surface of the base of the skull, in the region of the anterior and middle cranial fossae, and the posterior ones - on the cerebellum

medial surface directed towards the longitudinal fissure of the brain.

In each hemisphere, the most protruding places are distinguished: in front - the frontal pole, behind - the occipital, and on the side - the temporal.

The hemisphere is divided into five lobes. Four of them are adjacent to the corresponding bones of the cranial vault:

The frontal, parietal, occipital, temporal, insular lobes separate the frontal lobe from the temporal.

The structure of the cerebral cortex and the interaction between its individual parts is called the architectonics of the cerebral cortex. The place where the cerebral cortex performs certain functions: analysis of information coming from the sense organs, their preservation, etc., are largely determined by the internal structure and the construction of connections (morphology) within specific areas of the brain (such areas are called cortical fields). Another important function of the cerebral cortex is connection with certain external receivers of information(receptors), which are all the sense organs, as well as with organs and tissues that carry out commands coming from the cerebral cortex (effectors).

Everything that a person sees is recognized and analyzed in occipital region the cerebral cortex, while the eye is just an image receiver that transmits it along the nerve fibers for analysis to the occipital visual zone.

In the event that the image is moving, then the analysis of the movement of this image occurs in parietal region, and as a result of this analysis, we determine in which direction and at what speed the object we see is moving.

Parietal areas of the cortex, together with the temporal zones the cortex takes part in the formation of the act of articulate speech and in the perception of the shape of the human body and its location in space.

frontal lobes the human cerebral cortex are those parts of the cortex that mainly carry out higher mental functions, manifested in the formation of personal qualities, temperament, character, abilities, will, rationality of behavior, creative inclinations and giftedness, drives and addictions, in general, everything that makes a person a person who is not like all other people, and in building purposeful behavior based on foresight. All these abilities are sharply disturbed when the frontal parts of the cerebral cortex are damaged.

The most extensive damage to the cerebral cortex is accompanied by the complete disappearance of mental activity.

The cerebral cortex is the youngest formation of the CNS. In phylogenesis, the volume of the new cortex (cloak) increases. Thus, the new cortex in relation to the entire cortex in a hedgehog is 32.4%, in a rabbit - 56, in a dog - 84.2, and in humans - 95.9%.

The cerebral cortex consists of three zones: ancient, old and new. The ancient cortex includes the olfactory lobe, the lateral olfactory gyrus. The old cortex consists of the hippocampal and dentate gyrus. The neocortex is a projection zone of external reception on the field of perceived cortical neurons. In humans, the surface of the new cortex is 1500 cm 3. The rapid development of projection fields, associative areas of the cortex, and the slow development of the bones of the skull led to the formation of folds: furrows and convolutions.

The cortex is made up of 14 billion cells arranged in six layers (Figure 3.11).

• 1. The molecular layer of the cerebral cortex - formed by fibers woven together, contains few cells.
• 2. The outer granular layer of the cerebral cortex - is characterized by a dense arrangement of small neurons of various shapes.
• 3. The outer pyramidal layer of the cerebral cortex - consists mainly of pyramidal neurons of different sizes, larger cells lie deeper.
• 4. The inner granular layer of the cerebral cortex - is characterized by a loose arrangement of small neurons of various sizes, past which dense bundles of fibers pass perpendicular to the surface of the cortex.
• 5. Inner pyramidal layer of the cerebral cortex - consists mainly of medium and large pyramidal neurons, the apical dendrites of which extend to the molecular layer.
• 6. The layer of spindle-shaped cells of the cerebral cortex - spindle-shaped neurons are located in it, the deep part of this layer passes into the white matter of the brain. Layers 2, 4 and 6 composed of receptive cells. Layers 3 and 5 - pyramidal, giving rise to descending motor pathways. The ascending path passes through all cortical layers (specific path). The non-specific pathway also passes through all cortical layers.

As the Kyiv anatomist V.A. Betz, not only the type of nerve cells, but also their relative position is not the same in different parts of the cortex. The distribution of nerve cells in the cortex is referred to as "cytoarchitectonics". Research conducted by scientists from different countries at the end of the 19th and beginning of the 20th century allowed

Rice. 3.11.

S.G. Krivoshchekov, 2012)

to create cytoarchitectonic maps of the cerebral cortex of humans and animals, which were based on the structural features of the cortex in each part of the hemisphere. K. Brodman singled out 52 cytoarchitectonic fields in the cortex, F. Vogt and O. Vogt, taking into account the fiber structure, described 150 myeloarchitectonic areas in the cerebral cortex.

The white matter of the hemispheres is located between the cortex and the basal ganglia. It consists of a large number of fibers running in different directions. These are the pathways of the telencephalon. There are three types of these paths:

• 1) projection path. It connects the cortex with the diencephalon and other parts of the central nervous system. These are ascending and descending paths;
• 2) commissural way. Its fibers are part of the cerebral commissures that connect the corresponding parts of the right and left hemispheres. They are part of the corpus callosum;
• 3) associative paths connect areas of the cortex of the same hemisphere.

In the cerebral cortex there are higher regulatory centers that provide control and regulation of all reflex processes of the body, mental activity, behavior, perception of all types of sensitivity.

Electrical activity of the cerebral cortex. Changes in the functional state of the cortex are reflected in the nature of its biopotentials. Registration of an electroencephalogram (EEG), i.e. electrical activity of the cortex, can be produced through intact integuments of the head (in natural conditions in animals and humans) and the total activity of all neurons closest to the surface can be recorded. Modern electroencephalographs amplify these potentials by 2-3 million times and make it possible to study the EEG from many points of the cortex simultaneously.

In the EEG, certain frequency ranges are distinguished, called EEG rhythms, and wave amplitudes (Fig. 3.12). In a state of relative rest, an alpha rhythm is most often recorded, in a state of active attention - a beta rhythm, when falling asleep, in some emotional states - a theta rhythm, in deep sleep, loss of consciousness, anesthesia - a delta rhythm.

The EEG reflects the features of the interaction of cortical neurons during mental and physical work. The lack of well-established coordination when performing unusual or hard work leads to the so-called EEG desynchronization - rapid asynchronous activity.

In the process of learning and mastering various motor skills, the functions of the cerebral cortex are restructured and improved: the amplitude and regularity of the manifestation of background activity - the alpha rhythm at rest - increase significantly, compared to the state of relative rest, the interconnectedness (synchronism and in-phase) of the electrical

Rice. 3.12. Biopotentials of the cerebral cortex on the EEG (J. Hassett, 1981) of the activity of various areas of the cortex. This facilitates functional interactions between different cortical centers. Between these zones, a common rhythm of activity is established. Such characteristic systems of interacting cortical zones include not only primary fields (motor, visual, etc.), but also secondary (for example, premotor, etc.) and especially tertiary fields: anterior - programming frontal areas and posterior - zones of afferent synthesis (lower parietal and etc.).

glial cells; it is located in some parts of the deep brain structures, the cortex of the cerebral hemispheres (as well as the cerebellum) is formed from this substance.

Each hemisphere is divided into five lobes, four of which (frontal, parietal, occipital and temporal) are adjacent to the corresponding bones of the cranial vault, and one (insular) is located in depth, in the fossa that separates the frontal and temporal lobes.

The cerebral cortex has a thickness of 1.5–4.5 mm, its area increases due to the presence of furrows; it is connected with other parts of the central nervous system, thanks to the impulses that neurons conduct.

The hemispheres make up approximately 80% of the total mass of the brain. They carry out the regulation of higher mental functions, while the brain stem is lower, which are associated with the activity of internal organs.

Three main regions are distinguished on the hemispheric surface:

• convex upper lateral, which is adjacent to the inner surface of the cranial vault;
• lower, with the anterior and middle sections located on the inner surface of the cranial base and the posterior ones in the region of the cerebellum;
• the medial is located at the longitudinal fissure of the brain.

Features of the device and activities

The cerebral cortex is divided into 4 types:

• ancient - occupies a little more than 0.5% of the entire surface of the hemispheres;
• old - 2.2%;
• new - more than 95%;
• the average is about 1.5%.

The phylogenetically ancient cerebral cortex, represented by groups of large neurons, is pushed aside by the new one to the base of the hemispheres, becoming a narrow strip. And the old one, consisting of three cell layers, shifts closer to the middle. The main region of the old cortex is the hippocampus, which is the central department of the limbic system. The middle (intermediate) crust is a formation of a transitional type, since the transformation of old structures into new ones is carried out gradually.

The human cerebral cortex, unlike that of mammals, is also responsible for the coordinated work of internal organs. Such a phenomenon, in which the role of the cortex in the implementation of all the functional activities of the body increases, is called the corticalization of functions.

One of the features of the cortex is its electrical activity, which occurs spontaneously. Nerve cells located in this section have a certain rhythmic activity, reflecting biochemical, biophysical processes. Activity has a different amplitude and frequency (alpha, beta, delta, theta rhythms), which depends on the influence of numerous factors (meditation, sleep phases, stress, the presence of convulsions, neoplasms).

Structure

The cerebral cortex is a multilayer formation: each of the layers has its own specific composition of neurocytes, a specific orientation, and the location of processes.

The systematic position of neurons in the cortex is called "cytoarchitectonics", the fibers arranged in a certain order are called "myeloarchitectonics".

The cerebral cortex consists of six cytoarchitectonic layers.

1. Surface molecular, in which there are not very many nerve cells. Their processes are located in himself, and they do not go beyond.
2. The outer granular is formed from pyramidal and stellate neurocytes. The processes leave this layer and go to the next ones.
3. Pyramidal consists of pyramidal cells. Their axons go down where they end or form association fibers, and their dendrites go up to the second layer.
4. The internal granular is formed by stellate cells and small pyramidal. The dendrites go into the first layer, the lateral processes branch out within their own layer. Axons extend into the upper layers or into the white matter.
5. Ganglionic is formed by large pyramidal cells. Here are the largest neurocytes of the cortex. The dendrites are directed to the first layer or distributed in their own. Axons leave the cortex and begin to be fibers that connect various departments and structures of the central nervous system with each other.
6. Multiform - consists of various cells. Dendrites go to the molecular layer (some only up to the fourth or fifth layers). Axons are sent to the overlying layers or exit the cortex as association fibers.

The cerebral cortex is divided into regions - the so-called horizontal organization. There are 11 of them in total, and they include 52 fields, each of which has its own serial number.

Vertical organization

There is also a vertical division - into columns of neurons. In this case, small columns are combined into macro columns, which are called a functional module. At the heart of such systems are stellate cells - their axons, as well as their horizontal connections with the lateral axons of pyramidal neurocytes. All nerve cells in the vertical columns respond to the afferent impulse in the same way and together send an efferent signal. Excitation in the horizontal direction is due to the activity of transverse fibers that follow from one column to another.

He first discovered units that unite neurons of different layers vertically in 1943. Lorente de No - with the help of histology. Subsequently, this was confirmed using methods of electrophysiology on animals by W. Mountcastle.

The development of the cortex in fetal development begins early: as early as 8 weeks, the embryo has a cortical plate. First, the lower layers differentiate, and at 6 months, the unborn child has all the fields that are present in an adult. The cytoarchitectonic features of the cortex are fully formed by the age of 7, but the bodies of neurocytes increase even up to 18. For the formation of the cortex, coordinated movement and division of precursor cells from which neurons emerge are necessary. It has been established that this process is influenced by a special gene.

Horizontal organization

It is customary to divide the areas of the cerebral cortex into:

• associative;
• sensory (sensitive);
• motor.

When studying localized areas and their functional characteristics, scientists used a variety of methods: chemical or physical irritation, partial removal of brain areas, development of conditioned reflexes, registration of brain biocurrents.

sensitive

These areas occupy approximately 20% of the cortex. The defeat of such zones leads to a violation of sensitivity (reduction of vision, hearing, smell, etc.). The area of ​​the zone directly depends on the number of nerve cells that perceive the impulse from certain receptors: the more there are, the higher the sensitivity. Allocate zones:

• somatosensory (responsible for skin, proprioceptive, autonomic sensitivity) - it is located in the parietal lobe (postcentral gyrus);
• visual, bilateral damage that leads to complete blindness - located in the occipital lobe;
• auditory (located in the temporal lobe);
• taste, located in the parietal lobe (localization - postcentral gyrus);
• olfactory, bilateral violation of which leads to loss of smell (located in the hippocampal gyrus).

Violation of the auditory zone does not lead to deafness, but other symptoms appear. For example, the impossibility of distinguishing short sounds, the meaning of everyday noises (steps, pouring water, etc.) while maintaining the difference in pitch, duration, and timbre. Amusia can also occur, which consists in the inability to recognize, reproduce melodies, and also distinguish between them. Music can also be accompanied by unpleasant sensations.

Impulses going along afferent fibers from the left side of the body are perceived by the right hemisphere, and from the right side - by the left (damage to the left hemisphere will cause a violation of sensitivity on the right side and vice versa). This is due to the fact that each postcentral gyrus is connected to the opposite part of the body.

Motor

The motor areas, the irritation of which causes the movement of the muscles, are located in the anterior central gyrus of the frontal lobe. Motor areas communicate with sensory areas.

The motor pathways in the medulla oblongata (and partially in the spinal cord) form a decussation with a transition to the opposite side. This leads to the fact that the irritation that occurs in the left hemisphere enters the right half of the body, and vice versa. Therefore, damage to the cortex of one of the hemispheres leads to a violation of the motor function of the muscles on the opposite side of the body.

The motor and sensory areas, which are located in the region of the central sulcus, are combined into one formation - the sensorimotor zone.

Neurology and neuropsychology have accumulated a lot of information about how the defeat of these areas leads not only to elementary movement disorders (paralysis, paresis, tremors), but also to disturbances in voluntary movements and actions with objects - apraxia. When they appear, movements during writing may be disturbed, spatial representations may be disturbed, and uncontrolled patterned movements may appear.

Associative

These zones are responsible for linking the incoming sensory information with the one that was previously received and stored in memory. In addition, they allow you to compare information that comes from different receptors. The response to the signal is formed in the associative zone and transmitted to the motor zone. Thus, each associative area is responsible for the processes of memory, learning and thinking.. Large associative zones are located next to the corresponding functional sensory zones. For example, any associative visual function is controlled by the visual association area, which is located next to the sensory visual area.

Establishing the laws of the brain, analyzing its local disorders and checking its activity is carried out by the science of neuropsychology, which is located at the intersection of neurobiology, psychology, psychiatry and informatics.

Features of localization by fields

The cerebral cortex is plastic, which affects the transition of the functions of one department, if it is disturbed, to another. This is due to the fact that the analyzers in the cortex have a core, where the highest activity takes place, and a periphery, which is responsible for the processes of analysis and synthesis in a primitive form. Between the analyzer cores there are elements that belong to different analyzers. If the damage touches the nucleus, peripheral components begin to take responsibility for its activity.

Thus, the localization of functions possessed by the cerebral cortex is a relative concept, since there are no definite boundaries. However, cytoarchitectonics suggests the presence of 52 fields that communicate with each other through pathways:

• associative (this type of nerve fibers is responsible for the activity of the cortex in the region of one hemisphere);
• commissural (connect symmetrical areas of both hemispheres);
• projection (contribute to the communication of the cortex, subcortical structures with other organs).

Table 1

		Relevant fields
Motor
sensitive
visual
Olfactory
Taste
Speech motor, which includes centers:	Wernicke, which allows you to perceive oral speech
	Broca - responsible for the movement of the tongue muscles; defeat threatens with a complete loss of speech
	Perception of speech in writing

So, the structure of the cerebral cortex involves considering it in a horizontal and vertical orientation. Depending on this, vertical columns of neurons and zones located in the horizontal plane are distinguished. The main functions performed by the cortex are reduced to the implementation of behavior, regulation of thinking, consciousness. In addition, it ensures the interaction of the body with the external environment and takes part in the control of the work of internal organs.