Functions of the cerebral hemisphere. Functions of the diencephalon and cerebral hemispheres (forebrain) of the brain

slide 4

Topography of the diencephalon

• The diencephalon (diencephalon) is the part of the brain that makes up the human topmost part of the brain stem over which the cerebral hemispheres are located.

slide 5

Parts of the diencephalon

• epiphysis
• Hypothalamus
• thalamus
• Pituitary
• cerebellum
• Medulla
• corpus callosum

slide 6

Thalamus - visual tubercle

Thalamus (thalamus, visual tubercle) is a structure in which the processing and integration of almost all signals going to the cerebral cortex from the spinal cord, midbrain, cerebellum, and basal ganglia of the brain takes place.

• 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

Slide 7

Hypothalamus - hypothalamus

The hypothalamus (hypothalamus) or hypothalamus is a part of the brain located below the thalamus, or "visual hillocks", for which it got its name.

Higher subcortical center of autonomic nervous system and all vital functions

• Ensuring the constancy of the internal environment and metabolic processes of the body.
• Regulation of motivated behavior and defensive reactions (thirst, hunger, satiety, fear, rage, pleasure and displeasure)
• Participation in the change of sleep and wakefulness.

Slide 8

Hypothalamo - pituitary system

• The hypothalamus, in response to nerve impulses, has a stimulating or inhibitory effect on the anterior pituitary gland. Through the pituitary hormones, the hypothalamus regulates the function of the peripheral endocrine glands.

Slide 9

Pineal gland - pineal gland

• The main functions of the pineal gland in the body
  • Regulation of seasonal rhythms of the body
  • Regulation of reproductive function
  • Antioxidant defense of the body
  • Antitumor protection
  • "Sundial of Aging"
• Melatonin is a hormone of the pineal gland.
  • And if the epiphysis is likened biological clock, then melatonin can be likened to a pendulum that ensures the movement of these clocks and a decrease in the amplitude of which leads to their stop.

Slide 10

Large hemispheres of the brain

• The largest part of the brain, accounting for about 70% of its weight in adults. Normally, the hemispheres are symmetrical. They are interconnected by a massive bundle of axons (corpus callosum), which ensures the exchange of information.
• Each hemisphere consists of four lobes: frontal, parietal, temporal and occipital. The lobes of the cerebral hemispheres are separated from one another by deep furrows.
• central sulcus
• Lateral furrow
• Parieto-occipital sulcus

slide 11

The cerebral cortex

• The cerebral cortex plays 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 surface area of ​​the cortex of one hemisphere in an adult is on average 220,000 mm². The superficial parts account for 1/3, and those lying in depth between the convolutions - 2/3 of the entire area of ​​the cortex.

slide 12

slide 13

Label the parts of the brain

1 - telencephalon

2 - diencephalon

3 - midbrain

5 - cerebellum

6 - medulla oblongata

Slide 14

Repeat and remember

• diencephalon
• thalamus
• Medulla
• midbrain
• Hypothalamus
• cerebellum
• Large hemispheres of the brain

slide 15

Identify errors

1. Hypothalamus

3. Diencephalon

5. Medulla oblongata

6. Midbrain

7. Large hemispheres

1 - Large hemispheres 2 - Cerebellum 3 - Medulla oblongata 4 - Bridge 5 - Hypothalamus 6 - Diencephalon

7 - Thalamus 8 - Midbrain

4. Thalamus

8. Cerebellum

slide 16

Homework

• P. 46 continue filling in the table
• Repeat item 45

Slide 17

Literature and Internet resources

Human biology in tables, figures and diagrams. Rezanova E.A., Antonova I.P., Rezanov A.A. M., Publishing School

View all slides

Abstract

Related lesson:

The body's fight against infection. Immunity"

Tasks:

Show the role of barriers that protect the human body from the aggression of microorganisms at the level skin, internal environment, cells;

Continue the formation of the concept of immunity and its type (non-specific, specific);

Expand knowledge of cellular and humoral immunity;

Enter information about organs immune system;

Show the difference between the concepts of "inflammation" and " common disease', including infectious diseases

Equipment: tables "Circulatory and lymphatic system”, “Composition of blood”, “Blood”, “Glands of internal secretion”, “Structure of tubular bone”, phagocytosis scheme, portraits of L. Pasteur, E. Jenner, I.I. Mechnikov

During the classes:

I organizational moment

II Test of knowledge

In the previous lesson, we got acquainted with the components of the internal environment of the body, found out how these components are interconnected, and also studied in detail the composition and functions of blood cells. Let's review everything we've learned on this topic.

Individual survey:

(two students are invited to complete assignments on the cards on the board,

the third student completes the task on the piece of paper)

Card 1: "The internal environment of the body" (a basic level of)

The internal environment of the body is...

Fill in the chart:

Card 2: Fill in the table "Blood cells and their meaning" (high level)

Card 3: Complete the task: (high level)

Labels were lost on human and frog blood products in the biological laboratory. How can you tell where is the blood? Give a reasoned answer.

(Large erythrocytes containing a nucleus cannot belong to a person. Therefore, this is the blood of a frog. Small non-nuclear erythrocytes can belong to a person)

Front poll:

What formed elements of blood do you know?

How does the structure and composition of an erythrocyte ensure its function?

Why is carbon monoxide dangerous to the body?

What is the function of leukocytes?

What is phagocytosis and phagocytes?

How is the process of phagocytosis carried out?

What is the name of the scientist who discovered this phenomenon?

What cells are capable of phagocytosis?

What is the mechanism of thrombus formation?

What is the importance of blood clotting for the body?

The presence of what substances in the blood plasma causes the process of coagulation?

What blood parameters are determined in a blood test?

What is anemia? Why is it dangerous?

What organs in the body are responsible for the process of hematopoiesis?

III main part

1. Knowledge update

A person lives in an environment of various microbes: bacteria, viruses, fungi, protozoa. Every body is protected from them. different ways. Today in the lesson we will analyze the main mechanisms of protection of the human body from various infections. The topic of today's lesson is “The body's fight against infection. Immunity"

2. Protective barriers of the body

Immunity - the body's ability to protect itself from pathogenic m / o and viruses, as well as from foreign bodies and substances, ensuring the constancy of the internal environment of the body

3. Forms and mechanisms of immunity

The oldest form of immunity is nonspecific immunity, which acts on all types of world organisms, regardless of their chemical nature. Another form of immunity specific immunity- is associated with the ability of the body to recognize substances other than its cells and tissues, and to destroy only these foreign cells and substances.

phagocytosis

(I.I. Mechnikov) neutralization

Antigens - foreign substances and microorganisms that can cause

immune response.

* microbes, viruses, any other cells

Mechanisms of immunity

Cellular mechanism of immunity

Destruction harmful factor phagocyte cells

Humoral mechanism of immunity

Destruction of a harmful factor with the help of substances secreted by the cell itself

* interferon

4. Hematopoietic organs

Vertebrates have special organs where blood cells are formed that participate in the immune response.

Central organs of the immune system:

Bone marrow

Is located in tubular bones skeleton. Produces white blood cells that enter the bloodstream.

Thymus (thymus gland)

The thymus is located at the base of the neck, behind the sternum. Produces T-lymphocytes.

Peripheral organs of the immune system:

Spleen

It is located in the left hypochondrium. Contains a large number of T-lymphocytes and B-lymphocytes, which provide an immunological "check" of the blood.

The lymph nodes

Arranged along the way lymphatic vessels. Contains B-lymphocytes, T-lymphocytes, macrophages.

5. Inflammation Rice. 47 p.92

Signs:

1. redness of the affected area

2. rise in temperature

4. suppuration

Inflammation - This local reaction organism for the penetration of m / o, viruses, various

Meaning:

1. prevent the spread of germs throughout the body

2. complete destruction of microbes

Pus dead m/o and phagocytes

Ilya Ilyich Mechnikov

Russian and French biologist (zoologist, embryologist, immunologist, physiologist and pathologist). Born on May 15, 1845 in the village of Ivanovka, Kharkov province of the Russian Empire.

One of the founders of evolutionary embryology, the discoverer of phagocytosis and intracellular digestion, the creator of the comparative pathology of inflammation, the phagocytic theory of immunity, the founder of scientific gerontology.

Winner of the Nobel Prize in Physiology or Medicine (1908).

Having discovered the phenomena of phagocytosis in 1882 (which he reported on in 1883 at the 7th congress of Russian natural scientists and doctors in Odessa), he developed on the basis of his study a comparative pathology of inflammation (1892), and later - the phagocytic theory of immunity ("Immunity in infectious diseases" - 1901).

Numerous works by Mechnikov on bacteriology are devoted to the epidemiology of cholera, typhoid fever, tuberculosis and other infectious diseases.

IV Work with the textbook

Infectious diseases

Using the text of §18, complete the following tasks: pp.91-92

A basic level of:

What diseases are called infectious?

Specify distinctive features infectious diseases

List infectious diseases known to you.

Advanced level:

What is the "gate of infection"?

List the main stages in the development of an infectious disease.

In which case, when an infection enters the body, the disease does not develop?

High level:

Why are bacilli and virus carriers dangerous?

What is the mechanism of formation of such a carriage?

What is the difference between an AIDS patient and an HIV carrier?

Checking the correct execution of tasks

Conclusion: immunity developed to one of the pathogens does not guarantee against

infecting others.

? What are the possible measures to prevent infectious diseases?

thorough washing of hands, fruits and vegetables

boiling, treatment with disinfectants

isolation and treatment of the sick

compliance with personal hygiene measures

preventive vaccinations, therapeutic serums

V Fixing

1. Match

2. Fill in the gaps in the text

Immunity is the ability of the body to get rid of ……………. bodies and compounds, to preserve the chemical ……………….. of the internal environment and biological individuality. The first barrier to pathogenic factors are ………….. and …………… membranes. The second barrier to pathogenic factors is ………….. body environment (…………. and lymph). The immune system consists of ……………………. brain, thymus gland (thymus), lymph nodes, ……………. .

3. Fill in the gaps in the text

Acquired Immune Deficiency Syndrome (AIDS) is an epidemic human disease affecting 150 countries of the world. The disease affects mainly …………… the human system. The causative agent of the disease is ……………………….. (HIV). As a result of its penetration into the body, a person becomes defenseless to microbes, in normal conditions not causing disease. One of the most common ways of transmitting HIV and spreading AIDS is ……………………. . AIDS prevention measures are: ……………………………………………………. .

VI Lesson summary

The body has two barriers of defense against disease-causing organisms.

The protective reaction of the body to the introduction of pathogenic m / o, viruses, foreign bodies and substances is called immunity.

There are two forms of immunity: non-specific immunity (affects all types of m / o) and specific immunity (affects a specific antigen).

The cells that carry out the immune reaction in the body are B-lymphocytes, T-lymphocytes, macrophages, which are formed by the organs of the immune system.

Infectious diseases differ from others in that they are contagious, have a cyclic course and form post-infectious immunity.

VII Homework

Learn §18; Be able to answer questions after the paragraph.

Prepare messages: "L. Pasteur. Vaccine. Healing Serums»

“E. Jenner. Smallpox vaccination methods»

Educational, methodical literature:

Kolesov D.V., Mash R.D., Belyaev I.N. "Biology: Man." Textbook for grade 8. M: Bustard, 2008

Kolesov D.V. "Biology. Human". Thematic and lesson planning for the textbook by D.V. Kolesova, R.D. Mash, I.N. Belyaev. M: Bustard, 2004

Anisimova V.S., Brunovt E.P., Rebrova L.V. “Independent work of students in anatomy. Human Physiology and Hygiene” Teacher's Manual. M: Enlightenment, 1987

macrophages

leukocytes

specific

nonspecific

Forms of immunity

DISEASE

Blood (leukocytes); lymph (lymphocytes); tissue fluid (macrophages)

Skin, mucous membranes (tears, sweat, saliva, hydrochloric acid) + m / o living on the skin and mucous membranes

m/o penetration

Components of the internal environment

lymphocytes

antibodies to antigens

macrophages

Cells of immunity

T-lymphocytes

B-lymphocytes

devour foreign substances, m / o, cells

form antibodies

make bacteria defenseless against phagocytes

secrete substances that kill bacteria and viruses

Out of the cage!

In a cage!

memory cells

plasma cells

T-killers

T-suppressors

T-helpers

convey information about the antigen

remembering information

about the antigen

alien

block excessive reactions of B-lymphocytes

Student Message

Natural Sciences Section

Brain located in the cranial cavity. In its structure, five main sections are distinguished: the medulla oblongata, midbrain, cerebellum, diencephalon and brain (Fig. 61). Sometimes another section is distinguished in the midbrain - bridge. Medulla , midbrain(with the bridge) and the cerebellum make up hindbrain, and the diencephalon and cerebral hemispheres - forebrain.

Up to the level of the midbrain, the brain is a single trunk, but, starting from the midbrain, it is divided into two symmetrical halves. At the level of the forebrain, the brain consists of two separate hemispheres, interconnected by special brain structures.

Parts of the brain and their functions

Medulla is the main part of the brain stem. It performs conductive and reflex functions. All the paths connecting the neurons of the spinal cord with the higher parts of the brain pass through it. By its origin, the medulla oblongata is the oldest thickening of the anterior end of the neural tube, and it contains the centers of many of the most important reflexes for human life. So, in the medulla oblongata is respiratory centerwhose neurons respond to an increase in the level of carbon dioxide in the blood between breaths. Artificial stimulation of the neurons of the anterior part of this center leads to narrowing of arterial vessels, an increase in pressure, and an increase in heart rate. Stimulation of neurons in the back of this center leads to the opposite effects.

In the medulla oblongata are the bodies of neurons, the processes of which form nervus vagus. In the medulla oblongata there are also centers of a number of protective reflexes(sneezing, coughing, vomiting), as well as reflexes associated with digestion (swallowing, salivation, etc.).

In the hypothalamus there are centers of hunger and thirst, the stimulation of the neurons of which leads to the indomitable absorption of food or water. Lesions of the hypothalamus are accompanied by severe endocrine and autonomic disorders: a decrease or increase in pressure, a decrease or increase in heart rate, breathing difficulties, intestinal motility disorders, thermoregulation disorders, changes in the composition of the blood.

Large hemispheres of the brain human are divided by a deep longitudinal slit into the left and right halves. Special jumper formed nerve fibers, corpus callosum- connects these two halves, ensuring the coordinated work of the cerebral hemispheres.

The youngest formation of the human brain in evolutionary terms is cerebral cortex. This is a thin layer of gray matter (neuronal bodies), only a few millimeters thick, covering the entire forebrain. The cortex is formed by several layers of neurons, and it includes most of all neurons of the human central nervous system.

deep furrows the cortex of each hemisphere is divided into lobes: frontal, parietal, occipital and temporal (Fig. 62). Various Functions the cortex is associated with different lobes. Between the furrows are the folds of the cortex of the hemispheres - convolutions. This structure allows you to significantly increase the surface of the cortex of the hemispheres. In the convolutions are the higher nerve centers. So, in the region of the anterior central gyrus of the frontal lobe, there are higher centers arbitrary movements, and in the region of the posterior central gyrus - the centers of musculoskeletal sensitivity. To date, the cortex has been mapped in detail and the representation of each muscle, each area of ​​the skin in the cerebral cortex, as well as those areas of the cortex in which certain sensations are formed, are precisely known.

IN occipital lobe the highest centers of visual sensations are located. This is where the visual image is formed. Information to the neurons of the occipital lobe comes from the visual nuclei of the thalamus.

IN temporal lobes higher auditory centers are located, containing different kinds neurons: some of them react to the beginning of a sound, others to a certain frequency band, and others to a certain rhythm. Information in this area comes from the auditory nuclei of the thalamus. The centers of taste and smell are located in the depths of the temporal lobes.

IN comes information about all the sensations. Here its summary analysis takes place and a holistic view of the image is created. Therefore, this area of ​​the cortex is called associative, it is with it that the ability to learn is associated. If the frontal cortex is destroyed, then there is no association between the type of object and its name, between the image of a letter and the sound that it denotes. Learning becomes impossible.

In the depths of the cerebral hemispheres are clusters of neurons that form nuclei limbic system, which is the main emotional center of the brain. The nuclei of the limbic system play an important role in memorizing new concepts and learning. At the very base of the brain are the limbic nuclei, in which the centers of fear, rage, and pleasure are found. The destruction of the nuclei of the limbic system leads to a decrease in emotionality, the absence of anxiety and fear, dementia.

All human activity is under the control of the cerebral cortex. This part of the brain ensures the interaction of the body with the environment and is the material basis for human mental activity.

New concepts

Brain stem. Brain. Medulla. Midbrain. Cerebellum. Intermediate brain. Large hemispheres. The cerebral cortex

Answer the questions

1. What departments form the brain stem? 2. Which reflex centers are located in the medulla oblongata? 3. What is the importance of the cerebellum in the human body? What parts of the brain help it perform its functions? 4. In what part of the brain are the highest centers of pain sensitivity located? 5. What disorders of the body occur in a person when the hypothalamus is disturbed? 6. What is the significance of the furrows and convolutions in the structure of the cerebral hemispheres?

THINK!

How can you check for deviations in the work of the cerebellum?

New bark(neocortex) is a layer of gray matter with a total area of ​​​​1500-2200 square centimeters, covering the large hemispheres. The neocortex makes up about 72% of the total area of ​​the cortex and about 40% of the mass of the brain. The new bark contains 14 mln. Neurons, and the number of glial cells is approximately 10 times greater.

The cerebral cortex in phylogenetic terms is the youngest nervous structure. In humans, it carries out the highest regulation of body functions and psychophysiological processes that provide various forms of behavior.

In the direction from the surface of the new cortex in depth, six horizontal layers are distinguished.

molecular layer. It has very few cells, but a large number of branching dendrites of pyramidal cells forming a plexus parallel to the surface. On these dendrites, afferent fibers form synapses, coming from the associative and nonspecific nuclei of the thalamus.

Outer granular layer. Composed mainly of stellate and partially pyramidal cells. The fibers of the cells of this layer are located mainly along the surface of the cortex, forming corticocortical connections.

outer pyramidal layer. Consists mainly of pyramidal cells of medium size. The axons of these cells, like the granular cells of the 2nd layer, form corticocortical associative connections.

Inner granular layer. By the nature of the cells (stellate cells) and the location of their fibers, it is similar to the outer granular layer. In this layer, afferent fibers have synaptic endings coming from neurons of specific nuclei of the thalamus and, consequently, from receptors of sensory systems.

Inner pyramidal layer. Formed by medium and large pyramidal cells. Moreover, Betz's giant pyramidal cells are located in the motor cortex. The axons of these cells form the afferent corticospinal and corticobulbar motor pathways.

Layer of polymorphic cells. It is formed mainly by spindle-shaped cells, the axons of which form the corticothalamic pathways.

Assessing the afferent and efferent connections of the neocortex in general, it should be noted that in layers 1 and 4, the perception and processing of signals entering the cortex occurs. Neurons of the 2nd and 3rd layers carry out corticocortical associative connections. The efferent pathways leaving the cortex are formed mainly in the 5th and 6th layers.

Histological data show that the elementary neural circuits involved in information processing are located perpendicular to the surface of the cortex. At the same time, they are located in such a way that they capture all layers of the cortex. Such associations of neurons were called by scientists. neural columns. Neighboring neural columns can partially overlap and also interact with each other.

The increase in the phylogenesis of the role of the cerebral cortex, the analysis and regulation of body functions and the subordination of the underlying parts of the central nervous system by scientists are defined as function corticalization(Union).

Along with the corticalization of the functions of the neocortex, it is customary to single out the localization of its functions. The most commonly used approach to the functional division of the cerebral cortex is the allocation of sensory, associative and motor areas in it.

Sensory areas of the cortex - zones in which sensory stimuli are projected. They are located mainly in the parietal, temporal and occipital lobes. Afferent pathways enter the sensory cortex predominantly from specific sensory nuclei of the thalamus (central, posterior lateral, and medial). The sensory cortex has well-defined layers 2 and 4 and is called granular.

Areas of the sensory cortex, irritation or destruction of which causes clear and permanent changes in the sensitivity of the body, are called primary sensory areas(nuclear parts of analyzers, as I.P. Pavlov believed). They consist mainly of monomodal neurons and form sensations of the same quality. Primary sensory areas usually have a clear spatial (topographic) representation of body parts, their receptor fields.

Around the primary sensory areas are less localized secondary sensory areas, whose polymodal neurons respond to the action of several stimuli.

The most important sensory area is the parietal cortex of the postcentral gyrus and the corresponding part of the postcentral lobule on the medial surface of the hemispheres (fields 1–3), which is designated as somatosensory area. Here there is a projection of skin sensitivity of the opposite side of the body from tactile, pain, temperature receptors, interoceptive sensitivity and sensitivity of the musculoskeletal system from muscle, articular, tendon receptors. The projection of body parts in this area is characterized by the fact that the projection of the head and upper parts of the body is located in the inferolateral areas of the postcentral gyrus, the projection of the lower half of the trunk and legs is in the upper medial zones of the gyrus, and the projection of the lower part of the lower leg and feet is in the cortex of the postcentral lobule on the medial surface hemispheres (Fig. 12).

At the same time, the projection of the most sensitive areas (tongue, larynx, fingers, etc.) is relatively compared to other parts of the body.

Rice. 12. Projection of parts of the human body on the area of ​​the cortical end of the analyzer of general sensitivity

(section of the brain in the frontal plane)

In the depth of the lateral groove is located auditory cortex(cortex of the transverse temporal gyri of Heschl). In this zone, in response to irritation of the auditory receptors of the organ of Corti, sound sensations are formed that change in volume, tone, and other qualities. There is a clear topical projection here: in different plots the cortex presents various parts of the organ of Corti. The projection cortex of the temporal lobe also includes, as scientists suggest, the center of the vestibular analyzer in the superior and middle temporal gyri. The processed sensory information is used to form the "body map" and regulate the functions of the cerebellum (temporal-bridge-cerebellar pathway).

Another area of ​​the neocortex is located in the occipital cortex. This primary visual area. There is a topical representation of retinal receptors here. In this case, each point of the retina corresponds to its own area of ​​the visual cortex. In connection with the incomplete decussation of the visual pathways, the same halves of the retina are projected into the visual region of each hemisphere. The presence in each hemisphere of the projection of the retina of both eyes is the basis of binocular vision. Irritation of the cerebral cortex in this area leads to the appearance of light sensations. Near the primary visual area secondary visual area. The neurons of this region are polymodal and respond not only to light, but also to tactile and auditory stimuli. It is no coincidence that it is in this visual area that the synthesis of various types of sensitivity occurs and more complex visual images and their identification arise. Irritation of this area of ​​the cortex causes visual hallucinations, obsessive sensations, eye movements.

The main part of the information about the surrounding world and the internal environment of the body, received in the sensory cortex, is transmitted for further processing to the associative cortex.

Association areas of the cortex (intersensory, interanalyzer), includes areas of the new cerebral cortex, which are located next to the sensory and motor areas, but do not directly perform sensory or motor functions. The boundaries of these areas are not clearly marked, which is associated with the secondary projection zones, the functional properties of which are transitional between the properties of the primary projection and associative zones. The associative cortex is phylogenetically the youngest area of ​​the neocortex, which has received the greatest development in primates and humans. In humans, it makes up about 50% of the entire cortex, or 70% of the neocortex.

The main physiological feature of the neurons of the associative cortex, which distinguishes them from the neurons of the primary zones, is polysensory (polymodality). They respond with practically the same threshold not to one, but to several stimuli - visual, auditory, skin, etc. The polysensory nature of the neurons of the associative cortex is created both by its corticocortical connections with different projection zones, and by its main afferent input from the associative nuclei of the thalamus, in which complex processing of information from various sensory pathways has already taken place. As a result, the associative cortex is a powerful apparatus for the convergence of various sensory excitations, which makes it possible to perform complex processing of information about the external and internal environment of the body and use it to implement higher mental functions.

According to thalamocortical projections, two associative systems of the brain are distinguished:

thalamothemenal;

talomotemporal.

thalamotenal system it is represented by associative zones of the parietal cortex, which receive the main afferent inputs from the posterior group of associative nuclei of the thalamus (lateral posterior nucleus and pillow). The parietal association cortex has afferent outputs to the nuclei of the thalamus and hypothalamus, the motor cortex, and the nuclei of the extrapyramidal system. The main functions of the thalamo-temporal system are gnosis, the formation of a "body schema" and praxis.

Gnosis- these are various types of recognition: shapes, sizes, meanings of objects, understanding of speech, etc. Gnostic functions include the assessment of spatial relationships, for example, the relative position of objects. In the parietal cortex, the center of stereognosis is isolated (located behind the middle sections of the postcentral gyrus). It provides the ability to recognize objects by touch. A variant of the gnostic function is also the formation in the mind of a three-dimensional model of the body (“body schema”).

Under praxis understand purposeful action. The praxis center is located in the supramarginal gyrus and ensures the storage and implementation of the program of motorized automated acts (for example, combing, shaking hands, etc.).

Thalamolobic system. It is represented by associative zones of the frontal cortex, which have the main afferent input from the mediodorsal nucleus of the thalamus. The main function of the frontal associative cortex is the formation of goal-directed behavior programs, especially in a new environment for a person. The implementation of this function is based on other functions of the thalomolobic system, such as:

the formation of the dominant motivation that provides the direction of human behavior. This function is based on close bilateral connections between the frontal cortex and the limbic system and the role of the latter in the regulation of higher human emotions associated with social activities and creativity;

providing probabilistic forecasting, which is expressed in a change in behavior in response to changes in the environment and the dominant motivation;

self-control of actions by constantly comparing the result of the action with the original intentions, which is associated with the creation of a foresight apparatus (according to the theory of the functional system of P.K. Anokhin, the acceptor of the result of the action).

As a result of medically indicated prefrontal lobotomy, in which the connections between the frontal lobe and the thalamus intersect, there is the development of "emotional dullness", a lack of motivation, firm intentions and plans based on prediction. Such people become rude, tactless, they have a tendency to repeat any motor acts, although the changed situation requires the performance of completely different actions.

Along with the thalamo-temporal and thalamo-temporal systems, some scientists propose to distinguish the thalamo-temporal system. However, the concept of the thalamotemporal system has not yet received confirmation and sufficient scientific study. Scientists note a certain role temporal cortex. Thus, some associative centers (for example, stereognosis and praxis) also include sections of the temporal cortex. In the temporal cortex is the auditory center of Wernicke's speech, located in the posterior sections of the superior temporal gyrus. It is this center that provides speech gnosis - the recognition and storage of oral speech, both one's own and someone else's. In the middle part of the superior temporal gyrus, there is a center for recognizing musical sounds and their combinations. On the border of the temporal, parietal and occipital lobes there is a center for reading written speech, which provides recognition and storage of images of written speech.

It should also be noted that the psychophysiological functions performed by the associative cortex initiate behavior, an obligatory component of which is voluntary and purposeful movements, carried out with the obligatory participation of the motor cortex.

Motor areas of the cortex . The concept of the motor cortex of the cerebral hemispheres began to form in the 1980s, when it was shown that electrical stimulation of certain cortical zones in animals causes movement of the limbs of the opposite side. Based on modern research in the motor cortex, it is customary to distinguish two motor areas: primary and secondary.

IN primary motor cortex(precentral gyrus) are neurons that innervate the motor neurons of the muscles of the face, trunk and limbs. It has a clear topography of the projections of the muscles of the body. In this case, the projections of the muscles of the lower extremities and the trunk are located in the upper parts of the precentral gyrus and occupy a relatively small area, and the projection of the muscles of the upper extremities, face and tongue are located in the lower parts of the gyrus and occupy a large area. The main pattern of topographic representation is that the regulation of the activity of muscles that provide the most accurate and diverse movements (speech, writing, facial expressions) requires the participation of large areas of the motor cortex. Motor reactions to stimulation of the primary motor cortex are carried out with a minimum threshold, which indicates its high excitability. They (these motor reactions) are represented by elementary contractions of the opposite side of the body. With the defeat of this cortical region, the ability to fine coordinated movements of the limbs, especially the fingers, is lost.

secondary motor cortex. It is located on the lateral surface of the hemispheres, in front of the precentral gyrus (premotor cortex). It performs higher motor functions associated with the planning and coordination of voluntary movements. The premotor cortex receives the bulk of the efferent impulses from the basal ganglia and the cerebellum and is involved in recoding information about the plan of complex movements. Irritation of this area of ​​the cortex causes complex coordinated movements (for example, turning the head, eyes and torso in opposite directions). In the premotor cortex there are motor centers associated with human social functions: in the posterior part of the middle frontal gyrus is the center of written speech, in the posterior part of the inferior frontal gyrus is the center of motor speech (Broca's center), as well as the musical motor center, which determines the tonality of speech and the ability to sing.

The motor cortex is often referred to as the agranular cortex because the granular layers are poorly expressed in it, but the layer containing Betz's giant pyramidal cells is more pronounced. Motor cortex neurons receive afferent inputs through the thalamus from muscle, joint, and skin receptors, as well as from the basal ganglia and cerebellum. The main efferent output of the motor cortex to the stem and spinal motor centers is formed by pyramidal cells. Pyramidal and associated intercalary neurons are located vertically with respect to the surface of the cortex. Such adjacent neuronal complexes that perform similar functions are called functional motor columns. Pyramidal neurons of the motor column can excite or inhibit motoneurons of the stem and spinal centers. Neighboring columns functionally overlap, and pyramidal neurons that regulate the activity of one muscle are usually located in several columns.

The main efferent connections of the motor cortex are carried out through the pyramidal and extrapyramidal pathways, starting from the giant pyramidal cells of Betz and the smaller pyramidal cells of the cortex of the precentral gyrus, premotor cortex and postcentral gyrus.

pyramid path consists of 1 million fibers of the corticospinal tract, starting from the cortex of the upper and middle third of the precentral gyrus, and 20 million fibers of the corticobulbar tract, starting from the cortex of the lower third of the precentral gyrus. Arbitrary simple and complex goal-directed motor programs are carried out through the motor cortex and pyramidal pathways (for example, professional skills, the formation of which begins in the basal ganglia and ends in the secondary motor cortex). Most fibers pyramidal pathways performs the crossover. But a small part of them remain uncrossed, which helps to compensate for impaired movement functions in unilateral lesions. Through the pyramidal pathways, the premotor cortex also performs its functions (motor skills of writing, turning the head and eyes in the opposite direction, etc.).

To cortical extrapyramidal pathways include corticobulbar and corticoreticular pathways, starting approximately in the same area as the pyramidal pathways. The fibers of the corticobulbar pathway terminate on the neurons of the red nuclei of the midbrain, from which the rubrospinal pathways continue. The fibers of the corticoreticular pathways terminate on the neurons of the medial nuclei of the reticular formation of the pons (the medial reticulospinal pathways originate from them) and on the neurons of the reticular giant cell nuclei of the medulla oblongata, from which the lateral reticulospinal pathways originate. Through these pathways, the regulation of tone and posture is carried out, providing accurate targeted movements. Cortical extrapyramidal pathways are a component of the extrapyramidal system of the brain, which includes the cerebellum, basal ganglia, and motor centers of the brainstem. This system regulates tone, posture, coordination and correction of movements.

Assessing in general the role of various structures of the brain and spinal cord in the regulation of complex directional movements, it can be noted that the impulse (motivation) to move is created in the frontal system, the idea of ​​movement is created in the associative cortex of the cerebral hemispheres, the program of movements is in the basal ganglia, the cerebellum and the premotor cortex, and the execution of complex movements occurs through the motor cortex , motor centers of the trunk and spinal cord.

Interhemispheric relationships Interhemispheric relationships are manifested in humans in two main forms:

functional asymmetry of the cerebral hemispheres:

joint activity of the cerebral hemispheres.

Functional asymmetry of the hemispheres is the most important psychophysiological property of the human brain. The study of functional asymmetry of the hemispheres began in the middle of the 19th century, when the French physicians M. Dax and P. Broca showed that a person’s speech impairment occurs when the cortex of the inferior frontal gyrus, usually the left hemisphere, is damaged. Some time later, the German psychiatrist K. Wernicke discovered an auditory speech center in the posterior cortex of the upper temporal gyrus of the left hemisphere, the defeat of which leads to impaired understanding of oral speech. These data and the presence of motor asymmetry (right-handedness) contributed to the formation of the concept according to which a person is characterized by left-hemispheric dominance, which was formed evolutionarily as a result of labor activity and is a specific property of his brain. In the twentieth century, as a result of the use of various clinical techniques (especially in the study of patients with a split brain - transection was carried out), it was shown that in a number of psychophysiological functions, not the left, but the right hemisphere dominates in a person. Thus, the concept of partial dominance of the hemispheres arose (its author is R. Sperry).

It is customary to allocate mental, sensory And motor interhemispheric asymmetry of the brain. Again, in the study of speech, it was shown that the verbal information channel is controlled by the left hemisphere, and the non-verbal channel (voice, intonation) is controlled by the right. Abstract thinking and consciousness are predominantly associated with the left hemisphere. When developing a conditioned reflex, the right hemisphere dominates in the initial phase, and during exercises, that is, the strengthening of the reflex, the left hemisphere dominates. carries out the processing of information simultaneously statically, according to the principle of deduction, the spatial and relative features of objects are better perceived. performs information processing sequentially, analytically, according to the principle of induction, better perceives the absolute features of objects and temporal relationships. In the emotional sphere, the right hemisphere mainly determines the older, negative emotions, controls the manifestation of strong emotions. In general, the right hemisphere is "emotional". The left hemisphere determines mainly positive emotions, controls the manifestation of weaker emotions.

In the sensory realm, the role of the right and left hemispheres is best manifested in visual perception. The right hemisphere perceives the visual image holistically, immediately in all details, it is easier to solve the problem of distinguishing objects and identifying visual images of objects that are difficult to describe in words, creates the prerequisites for concrete-sensory thinking. The left hemisphere evaluates the visual image dissected. Familiar objects are more easily recognized and problems of similarity of objects are solved, visual images are devoid of specific details and have a high degree of abstraction, the prerequisites for logical thinking are created.

Motor asymmetry is due to the fact that the muscles of the hemispheres, providing a new, higher level of regulation complex functions brain, at the same time increases the requirements for combining the activities of the two hemispheres.

Joint activity of the cerebral hemispheres is provided by the presence of the commissural system (corpus callosum, anterior and posterior, hippocampal and habenular commissures, interthalamic fusion), which anatomically connect the two hemispheres of the brain.

Clinical studies have shown that in addition to the transverse commissural fibers that provide the interconnection of the cerebral hemispheres, there are also longitudinal, as well as vertical commissural fibers.

Questions for self-control:

General characteristics of the new cortex.

Functions of the new cortex.

The structure of the new cortex.

What are neural columns?

What areas of the cortex are distinguished by scientists?

Characteristics of the sensory cortex.

What are primary sensory areas? Their characteristic.

What are secondary sensory areas? Their functional purpose.

What is the somatosensory cortex and where is it located?

Characteristics of the auditory cortex.

Primary and secondary visual areas. Their general characteristics.

Characteristics of the association area of ​​the cortex.

Characteristics of the associative systems of the brain.

What is the thalamotenoid system. Her functions.

What is the thalamolobal system. Her functions.

General characteristics of the motor cortex.

Primary motor cortex; her characteristic.

secondary motor cortex; her characteristic.

What are functional motor columns.

Characteristics of the cortical pyramidal and extrapyramidal pathways.

This is the part of the forebrain located between the brain stem and the cerebral hemispheres. The main structures of the diencephalon are the thalamus, the pineal gland and the hypothalamus, to which the pituitary gland is attached.

thalamus can be called a collector of information about all kinds of sensitivity. It receives and processes almost all signals from the centers of the spinal cord, brain stem, cerebellum and RF. From it, information is delivered to the hypothalamus and the cerebral cortex.

In the thalamus are the nuclei, where O stimuli are synthesized, acting simultaneously. So, when you take a lump of ice in your hand, various neurons are excited: neurons, sensitive to mechanical influences, and those that perceive temperature changes, as well as sensitive eye neurons. However, all these signals simultaneously arrive in the same neurons in the nuclei of the thalamus. Here they are generalized, recoded, and complete information about the stimulus is transmitted to the cortex.

They are diverse, but the main difference between a person is a uniquely developed forebrain, and therefore most of the higher functions that distinguish a person from animals are performed by this particular department. The author of this article had the opportunity to read the most interesting and modern literature on this issue, so you can read about the functions of the brain regions associated with intelligence.

The newest function of the forebrain is planning and communication. This component of intelligence allows us to choose strategies in the process of communication that will be beneficial in the long run. This is done by the anterior lobes of the cerebral cortex. This department is responsible for the ability to reflect, recall the past and critically evaluate our activities, think through possible scenarios of events and decide the good old Hamlet question of whether we should act or not. Our organization depends on the degree of maturity of this area of ​​the brain. So the functions of the forebrain are not such knowledge abstracted from life. Although, of course, you should not blame only your biological characteristics for sloppiness. This feature can be developed.

All students and schoolchildren do not doubt the importance of such a function of the forebrain as memory. This is also a function of the cerebral cortex. Why don't we remember what happened to us until we were two years old? Because the area of ​​the cortex, which is responsible for conscious memory, was still immature. Recent studies allow us to conclude that the storage of information is located in those areas where the impulse came from the sense organs, so different types of memory are associated with different areas in the brain. However, satiety and fatigue are characteristic of all zones, therefore it is critical for a good memory to sleep enough (at least 7 hours), because it is during sleep that the brain transfers data from temporary resources to permanent ones. Therefore, when preparing for exams, it is good to break your day into two parts with an afternoon nap.

Emotions closely related to memory used by the very best teachers and leaders. They present the material so vividly that the students or workers have a strong emotional trace in the mind, and a person does not even have to make an effort to remember. Emotions are not only related to our performance, but also to immunity. In people who constantly experience negative emotions, the number of cells that fight the development of pathogens penetrating us is reduced. Also, negative emotions increase the level of cortisol, which destroys the brain. Therefore, you need to try to deceive the areas in the brain that are responsible for emotions. How to do it? Force the facial muscles to relax, then force yourself to smile artificially. You will immediately feel how the mood changes. This function of the forebrain is given insufficient importance in our rational world, but repressed emotions take revenge on a person with illnesses very cruelly. Different departments of a person are responsible for emotions, not only the forebrain, but also the cerebellum works.

Function speeches is critical for a person to feel good in society. Scientists, in addition, have noticed that a person who constantly shows speech activity is less likely to get it. So talk, read to yourself, write - and you will be healthy for a very long time. At least three areas in the brain are responsible for speech: part of the frontal gyrus, rear end the auditory cortex of the brain and the islet of Reil hidden in the depths.

Mathematical ability very important to us in Everyday life, even if the girls allow themselves to make mistakes from time to time, attributing everything to " female logic". The significance of this function of the forebrain is confirmed by the fact that for most highly paid professions it is critical to have good analytical brain function. The basic level of mathematical abilities is approximately the same for everyone, and a lot depends on the attitude to this activity and mood. It is also interesting that good musicians often have impressive mathematical abilities.

Spatial thinking- also a very useful "in life" function. It includes a whole range of skills - this is the ability to notice details, and the ability to form a layout of parts and compare existing data on similar structures with new ones. Busy with this process, basically the same areas that are responsible for vision.

As you can see, the forebrain is the base of our intelligence, the article talked about the different functions that are the components of intelligence. For those who are interested in the details, I recommend the book by David Gaymon and Allen Bragdon, which is called Superbrain. Manual."