Functions of parts of the brain

Functions

Basal ganglia (subcortical nuclei)

Role in the regulation and coordination of motor activity (together with the thalamus and cerebellum).

Participate in creating and remembering programs for goal-directed movements, learning and memory.

Functions of the cerebellum

The cerebellar hemispheres are connected to each other and are formed by gray and white matter

Coordination of voluntary movements and maintaining body position in space. Regulation muscle tone and balance

Functions of the medulla oblongata

Here are the nuclei with departing pairs of cranial nerves (hypoglossal, accessory, vagus, glossopharyngeal)

Conductor- connection between the spinal and overlying parts of the brain

Reflex:

regulation of the respiratory, cardiovascular and digestive systems;

food reflexes of salivation, chewing, swallowing;

protective reflexes: sneezing, blinking, coughing, vomiting

Functions of the diencephalon

Thalamus (optic thalamus with optic nerve nuclei)

Collection and evaluation of all incoming information from the senses. Isolation and transmission of the most important information to the cerebral cortex. Regulation of emotional behavior

Hypothalamus

The highest subcortical center of the autonomic nervous system and all vital functions of the body.

Ensuring the consistency of the internal environment and metabolic processes body.

Regulation of motivational behavior and defensive reactions (thirst, hunger, satiety, fear, rage, pleasure).

Participation in the transition between sleep and wakefulness

Functions of the midbrain

Four Hills with the nuclei of the primary visual and auditory centers

Brain stems with the nuclei of the oculomotor and trochlear nerves

Conductor

Reflex:

indicative reflexes to visual and sound stimuli, which manifest themselves in turning the head and body;

regulation of muscle tone and body posture

Functions of cortical zones

Zones

Functions

Frontal zone

Associated with many aspects of behavior and personality

Premotor zone

Coordinates individual movements

Motor somatic zone

Sends signals to muscles that carry out voluntary movements

Primary sensory area

Receives sensation data from skin, muscles, joints and organs

Associative sensory area

Analyzes data from sensory receptors

Visual association area

Analyzes data and forms a picture

Primary visual area

Receives nerve impulses from the eyes

Wernicke's zone

Interprets spoken language

Auditory association area

Analyzes audio data so we recognize words and melodies

Primary auditory zone

Determines sound characteristics such as pitch and volume

Broca's area

Necessary for speech formation

The human brain is not only the substrate of mental life, but also the regulator of all processes occurring in the body. The progressive development of the brain in higher primates, due first to tools and then to labor activity and articulate speech, allowed man to qualitatively stand out in the animal world and occupy a dominant position in nature.

The brain is located in the cranial cavity. Individual variations in brain mass modern man, regardless of the degree of his talent, are quite large (most often 1.1-1.7 kg). The brain mass of I.P. Pavlov (1653), D.I. Mendeleev (1571) and other great people was within such limits. Along with this, the brain mass of I.S. Turgenev (2012), Byron (1807), I.F. Schiller (1785) exceeded the maximum mass, and Anatole France (1017) had the minimum mass known for modern humans.

The brain of a newborn weighs on average 330-400 grams. In the embryonic period and in the first years of life, the brain grows rapidly, but only by the age of 20 does it reach its final size.

In the brain there are five divisions:

• Medulla oblongata;
• the hindbrain, consisting of the pons and cerebellum;
• the midbrain, including the cerebral peduncles and quadrigeminal region;
• the diencephalon, the main structures of which are the thalamus and hypothalamus;
• the forebrain (end) brain, represented by two cerebral hemispheres.

The first four make up the brainstem, which is the most ancient phylogenetically. The cerebral hemispheres are relatively young formations.

Medulla oblongata

The medulla oblongata is a direct continuation spinal cord upward, which explains its name, and in front it passes into the hindbrain. Its rear end is narrow, and its anterior end is wide.

On the anterior and posterior surfaces of the medulla oblongata there is one longitudinal groove, which are a direct continuation of the same grooves of the spinal cord. On each side of the anterior groove there is one protrusion called a pyramid.

If you dissect the medulla oblongata transversely, then on the cut surfaces you can see areas of gray matter (accumulations nerve cells), which received the names - olives, reticular formation (diffuse accumulation of cells various types, which are densely intertwined with many fibers running in different directions.

Functions of the medulla oblongata: the reticular formation is also present in other parts of the brain and plays a large role in regulating the excitability and tone of all parts of the central nervous system, etc. They are related to the regulation of balance and coordination of body movements, metabolism, respiration, and blood circulation. Here are the centers of the reflexes of sucking, swallowing, coughing, sneezing, and blinking.

White matter consists of fibers through which nerve impulses travel from the hindbrain to the spinal cord and in the opposite direction.

The pons and cerebellum are the hindbrain

The hindbrain includes the pons and cerebellum. The pons is located between the midbrain and the medulla oblongata. It seems to connect them, which is why it has such a name.

Its internal structure resembles the structure of the medulla oblongata, i.e. contains areas of gray and white matter. The gray matter makes up the centers of the cranial nerves and has the same reticular formation as in the medulla oblongata (see image above).

There are paths across the bridge nerve impulses from lower-lying departments to higher ones and in the opposite direction. There are centers and nerve fibers associated with the cerebellum.

The cerebellum is located under the occipital lobes of the cerebral hemispheres, behind the pons and medulla oblongata. It consists of two hemispheres and a small part located between them, the so-called worm.

The cerebellum contains a layer of gray matter called the cortex. Its surface consists of narrow convolutions. In the thickness of the cerebellum, among the white matter, there are nuclei of gray matter. With the help of the peduncles, the cerebellum is connected with the medulla oblongata and midbrain, the pons, and through them with the entire nervous system.

Main function of the cerebellum- coordination of movements, both voluntary and involuntary. With its help, the functions of balance and movement of the muscles of the neck, torso, and limbs are carried out, and muscle tone is maintained. Experiments show this. Destruction of small areas of the cerebellar cortex in animals does not cause significant impairment of its functions.

But the removal of half of the cerebellum is accompanied by severe disturbances in the movements of the side of the body on which the operation was performed. Over time, the severity of the disorders decreases, but they do not go away completely.

With painful lesions of the cerebellum, people develop rapid fatigue, trembling of the limbs, muscle tone, balance, dimension, and smoothness of body movements and speech are impaired.

Quadrigeminal peduncles - midbrain

The midbrain is located between the hindbrain and the diencephalon and, therefore, it carries out the morphological and functional connections of these sections. Nerve paths pass up and down through it; the subcortical centers of vision, hearing, muscle tone, and the nuclei of two cranial nerves are located in it.

The midbrain is represented by the quadrigeminal plate, the cerebral peduncles and the pineal gland, which belongs to the organs internal secretion. Its most studied function is the regulation of the formation of skin pigments. The cerebral peduncles connect the midbrain with the hindbrain.

Functions of the midbrain: transformation of received auditory and visual signals into motor actions. For example, when there is a loud sound, we reflexively turn towards the source. When a stimulus enters our field of vision, we automatically turn our eyes towards it. The midbrain is also involved in maintaining muscle tone, maintaining normal body posture in space, ensuring readiness skeletal muscles execute commands.

Thalamus and hypothalamus - diencephalon

In front, the midbrain passes into the diencephalon, ending with the brain stem. The diencephalon consists of the visual thalamus (thalamus) and the subthalamic region (hypothalamus). Here are located the subcortical centers (as opposed to the centers of the cerebral cortex) of vision, metabolism, heat regulation, and smell. Hence, diencephalon functions varied.

The optic thalamus is the main collector of nerve pathways to and from the cerebral hemispheres; contain areas of gray matter - clusters of neuron bodies. Here, rapid processing, splitting, and switching of incoming information to certain areas of the cerebral hemispheres from different parts of the body take place.

The subtubercular region (hypothalamus) is a complex of structures located below the thalamus and contains many nuclei. It is connected with the cerebral cortex, thalamus, cerebellum, and downwards it passes into the pituitary gland.

Functions of the hypothalamus:

• thermoregulation;
• regulation of metabolism;
• regulation of the cardiovascular system;
• regulation of endocrine glands, alimentary canal, urination;
• regulation of sleep and wakefulness, emotions, etc.

The diencephalon in front passes into the cerebral hemispheres.

Left and right hemispheres - forebrain (end) brain

The cerebral hemispheres are represented by the right and left, which are separated by a longitudinal fissure. Each hemisphere consists of gray matter - the cortex and nodes (nuclei) located deeper than it, between which there is white matter. The cortex covers the outside of the hemispheres.

From the cortex, deep into the brain, nerve processes extend, making up the fibers, which with their mass form the white matter - tissue white, acting as conductors of nerve impulses. The white matter contains clusters of nerve cells - nodes (nuclei) of the gray matter. This is the old part of the hemispheres, which is called the buttress. The subcortical centers of nervous activity are located here.

The surface of the cerebral hemispheres seems to be collected in folds of different sizes. Therefore, cracks, grooves and convolutions between them are visible. The three deepest sulci of the hemispheres are distinguished:

• Lateral;
• central;
• parieto-occipital.

They are the main guidelines for dividing the cerebral hemispheres into four main lobes:

• Frontal;
• parietal;
• temporal;
• occipital

The lateral sulcus separates the temporal lobe from the frontal and parietal lobes. The central sulcus separates the frontal and parietal lobes. The occipital lobe borders on the parietal lobe through the occipital-parietal groove, located on the side of the median surface of the hemispheres.

Inside the hemispheres of the brain there are cavities called ventricles. There are two such ventricles - one in the right, the other in the left hemisphere. They connect to the third and fourth ventricles of the brain stem and then to the canal inside the spinal cord, as well as to the space under the meninges.

The ventricles and spaces are filled with liquid (cerebrospinal fluid) and form a single hydrodynamic system, which, together with circulatory system ensures metabolism in the nervous system, and also creates reliable mechanical protection of nerve cells.

To summarize the description of the structure of the brain, we note that dividing it into various departments conditional and is done to facilitate learning. In fact, they are interconnected and act as one.

Independent work of students

Topic " Local systems brain and their functional organization"

Task 1. Using the content of the text “The Brain, Its Structure and Functions,” fill out the table:

Table 1.

Structure and functions of the brain

Task 2. Using a dictionary on the topic “Local brain systems and their functional organization,” fill out the table:

Table 2.

Local brain systems and their functional organization

The brain, its structure and functions Structure of the brain

Spinal cord, located in the spinal column, regulates the simplest automated muscle-motor reactions; it passes into the medulla oblongata of the brain.

Brain– the anterior section of the central nervous system of vertebrates, located in the cranial cavity; the main regulator of all vital functions of the body and the material substrate of its higher nervous activity. The human brain is most highly developed due to an increase in mass and a more complex structure of the cerebral cortex.

Brain

The outside of the brain is covered with connective tissue membranes in which blood vessels pass. The cavities of the brain - the ventricles - are a continuation of the spinal canal and are filled with liquid - cerebrospinal fluid. The brain, like the spinal cord, contains white and gray matter. The pathways connecting the brain with the spinal cord form white substance. They also connect different parts of the brain. Gray matter The brain is located in the form of separate clusters - nuclei - inside the white matter. In addition, gray matter covers the cerebral and cerebellar hemispheres and forms the cerebral cortex and cerebellar cortex. 12 pairs of cranial nerves arise from the brain.

Table 1. Sections of the brain

The medulla oblongata, pons and midbrain form brain stem.

Medulla oblongata It is a continuation of the spinal cord and connects it with the overlying parts of the brain. The anatomical position of the medulla oblongata determines its conductive function. All ascending and descending paths, connecting the centers of the brain and spinal cord. The medulla oblongata regulates various life support processes in the body - heart rhythm, breathing, blood pressure; coughing, blinking, lacrimation, vomiting, sucking, swallowing, etc.

The central part of the medulla oblongata is occupied by reticular formation(from Latin reticulum - mesh) - a diffuse network of highly branching interneurons. It extends to the thalamus. The reticular formation of the brain stem performs integrative-coordinating functions. It is involved in the regulation of excitability and maintaining the tone of all parts of the central nervous system, including the cerebral cortex. The activity of the reticular formation itself is supported by impulses coming from the ascending sensory pathways. In turn, the cerebral cortex exerts descending inhibitory influences on the reticular formation of the trunk. The reticular formation also receives descending influences from the cerebellum, subcortical nuclei, and limbic system. Reticular neurons are involved in the regulation of the cardiovascular system (maintaining blood pressure, regulating breathing.

Bridge(pons) acts as a switching center between parts of the brain, as well as between the spinal cord and brain and therefore plays important role in integration. Through the pontine nuclei, the cerebral cortex influences the cerebellum - this is the main channel of their communication. The pons contains the respiratory center, which, together with the respiratory center of the medulla oblongata, regulates breathing. The reticular formation of the pons (together with the medulla oblongata) is involved in regulating muscle tone, maintaining posture, and orienting the body in space. The vestibular nuclei are located here. In the reticular formation of the bridge there are centers that control rapid eye movements - saccades.

Constantio Varolius(1543-1575) - Italian anatomist, professor, physician to Pope Gregory XIII. He performed a large amount of research in the field of anatomy of the brain and cranial nerves.

Cerebellum consists of a worm and two hemispheres, the surface of which is formed by a highly folded multilayer cortex formed by several types of neurons (Purkinje cells, stellate, basket, etc.). In the depths of the hemispheres lie clusters of neurons - nuclei. From the cerebellar nuclei, some fibers go to the motor nuclei of the brain stem, the other part goes to the thalamus (diencephalon), and through it to the cerebral cortex. The cerebellum regulates motor acts. If its normal functioning is disrupted, the ability to make precise coordinated movements and maintain balance is lost. The functions of the cerebellar vermis are associated with the vestibular apparatus. The cerebellum receives information from other sensory systems: visual, auditory, somatosensory.

Purkinje Jan Evangelista(1787-1869) – Czech naturalist, professor, corresponding member. St. Petersburg Academy of Sciences, etc., one of the founders of the doctrine of the cellular structure of plants and animals.

Midbrain enters the brainstem, it connects the hindbrain with the forebrain, all nerve pathways from the sensory organs to the cerebral hemispheres pass through it. The mesencephalon includes the quadrigeminal cord and cerebral peduncles. The midbrain regulates the functioning of the sensory organs. Manifestation of innate orientation reflexes (listening, looking). The structures of the midbrain are involved in the regulation of movements and muscle tone, regulation of the acts of chewing, swallowing, their sequence, and provide precise hand movements, for example, when writing. The nuclei of the anterior colliculus are primary visual subcortical centers, nuclei of the posterior tubercles - auditory. Neurons of the anterior colliculus react to changes in light and darkness; turning the head in the direction of visual and auditory stimuli is associated with this part of the brain.

In the midbrain there is a formation continuing from the medulla oblongata - reticular formation. Impulses from the sense organs seem to charge this formation, and it has an activating (tonic) effect on the activity of the brain. The reticular formation of the midbrain plays an important role in the regulation of wakefulness and the state of involuntary attention.

Diencephalon– located above the midbrain. Includes thalamus(visual thalamus), hypothalamus(sub-tuberculous region), supra-tuberculous region, limbic system and controls different types sensitivity (somatic, pain, vision, hearing), complex vital (vital) reactions, nutrition, protection, reproduction, mental reactions (sleep, memory), maintaining homeostasis. Two endocrine glands are structurally and functionally connected to the diencephalon - the pituitary gland and the pineal gland.

Thalamus– complex multifunctional formation, including specific nuclei, where afferentation from the sensory organs switches to the corresponding areas of the cerebral cortex, associative nuclei, where this afferentation interacts and is partially processed, and nonspecific nuclei through which impulse flows from the reticular formation pass. These groups of nuclei are interconnected and a system of bilateral connections with the cerebral hemispheres. The thalamus is connected to the reticular formation of the brain stem, the hypothalamus and the cerebral cortex. The structure and numerous connections of the thalamus ensure its participation in the organization of complex motor reactions, such as sucking, chewing, swallowing, laughter, etc.

Hypothalamus– a center for regulating the activity of internal organs, the endocrine system, metabolism, body temperature, and the wake-sleep cycle. The hypothalamus, through the pituitary gland, controls the functioning of the endocrine glands and, thanks to this, is involved in the regulation of emotions and the formation of motivation.

Subcortical formations, regulating innate unconditioned reflex activity, are the area of ​​those processes that are subjectively felt in the form of emotions.

The structures of the human brain contain “experience” accumulated in the process of evolutionary development.

Telencephalon: basal ganglia (nuclei) and cerebral cortex.

Basal ganglia- a complex of subcortical nuclei, immersed in the white matter of the cerebral hemispheres and surrounded by fibers connecting them with the cerebral cortex.

Particularly developed in humans cerebral cortex– organ of higher mental functions. The cerebral cortex is a layer of gray matter formed by clusters of neurons. In the cortex of each hemisphere there are 4 lobes or regions: frontal, parietal, temporal and occipital. They are divided into smaller fields that differ from each other in their structure and purpose. In accordance with the most common classification proposed by K. Brodman, the cerebral cortex is divided into 11 regions and 52 fields.

Different fields of the cortex are characterized by features of their neurochemical composition. Thus, norepinephrine is found everywhere in cortical neurons, but is more abundant in the somatosensory cortex. It plays a special role in the perception of tactile information. Substances that increase the accumulation of norepinephrine in neurons (for example, cocaine) can cause hallucinations. Another substance, dopamine, is found in large quantities in the anterior parts of the frontal lobe, in the prefrontal field.

IN frontal lobe zone is located oral speech, centers of emotions, memory; center of logical thinking, coordinates the motor mechanisms of speech.

IN parietal– centers of musculocutaneous perception, spatial orientation, memory associated with speech and learning, center of somatic sensitivity.

IN temporal– centers of auditory perception, speech control, spatial analysis, memory center.

IN occipital– centers of visual perception.

Functional zones of the cortex. A feature of their organization is that signals from receptors are projected not onto one neuron, but onto a group of neurons. As a result, the signal is focused not only at one point (in one field), but spreads over a certain distance and captures a set of neurons. This ensures signal analysis and the possibility of its transmission to other brain structures. From their primary sensory areas, impulses spread to the associative and motor areas.

Sensory cortex receive specific sensory information: visual (occipital), auditory (temporal), motosensory and gustatory (parietal). The somatosensory cortex - the area of ​​muscle and skin sensitivity - is located in the posterior central gyrus, behind the central sulcus. When it is irritated, a sensation of touching, tingling, and numbness occurs. The largest area is occupied by the sensory area of ​​the hand, and then the vocal apparatus and face; the smallest dimensions are the sensory areas of the torso, thigh, and lower leg, i.e. areas with lower sensitivity.

Penfield scheme. Wilbur Graves Penfield(1891-1976, Nobel Prize, Canadian neurologist and neurosurgeon), together with I. Ramussen, created the famous drawings: “Sensory “homonculus” and “Motor “homonculus” - the cortical center of general sensitivity and the motor area of ​​the cerebral cortex.

"Homunculus" lat. - a little man, according to the ideas of medieval alchemists, is a certain creature that can be obtained artificially (in a flask).

 Sensory visual cortex located in occipital areas of the cortex.

 Sensory auditory zone is in temporal areas.

 Zone taste sensations located in parietal areas.

 Zone olfactory sensitivity located in old bark.

Motor(motor, afferent) zones are located in the anterior central gyrus of the frontal lobe.

Association zones receive impulses from all zones of the cortex. The associative cortex is the limbic cortex. The limbic system of the brain integrates three types of information: 1) about the work of internal organs, 2) from the sensory, motor and associative zones of the cortex, 3) from olfactory receptors.

The main structure of the cerebral hemispheres is the neocortex covering their surface. In the depths of the cerebral hemispheres there is an old cortex - the hippocampus and various large nuclear formations (basal ganglia) associated with the implementation of mental functions. There is also an ancient cortex that has only one layer of cells, not completely separated from the subcortical structures. Area of ​​new, old and ancient crust: ~96%, ~3%, ~1%.

Not everything is known to science. This mysterious organ is responsible for all processes in the human body: collecting information, analysis, forming a response, controlling the work of internal organs.

The central organ of the nervous system has a complex structural system and two division systems. The structure of the brain consists of 5 large sections:

1. Rear
2. Average
3. Oblong
4. Finite
5. Intermediate

The largest organs of the nervous system are represented by the cerebellum, brainstem, and two cerebral hemispheres.

The medulla of the brain is lined with three membranes, the origins of which are in the spinal cord. Each of meninges has a different structure:

• Vascular. The membrane is in close contact with the brain tissue, duplicating the relief. The connective tissue covering is permeated with a network blood vessels, follows the curves of the brain and descends into all grooves and convolutions. Tangles of vessels in the pia mater produce cerebrospinal fluid, which moves into cerebral ventricles(cavities filled with cerebrospinal fluid). The soft shell acts as a protector against harmful microorganisms.
• Arachnoid. A translucent membrane that does not have blood vessels. Its main task is to create free space between itself and the soft shell. In these spaces (tanks) moves cerebrospinal fluid, which plays the role of lymph - neutralizes pathogenic substances. The cisterns and ventricles of the brain interact with the subarachnoid spaces of the spinal membranes.
• Solid. A dense covering consisting of connective tissue fuses with the bones of the skull. Specific processes extend from the shell, which delimit the main large parts of the brain. The second task of the dura mater is to protect the brain matter from shock and damage. The growths hold the brain in place in an attempt to reduce the severity of the injury.

The estimated number of neurons is about 25 billion cells.

Structure and significance of departments

Oblong

This section is the connecting part between the brain and spinal cord. The structure of the medulla oblongata is similar to the spinal cord. However, the medulla oblongata is distinguished by a large accumulation of gray matter nuclei. A 2.5 cm long clot of tissue is responsible for the full functioning of several internal organ systems.

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The nuclei of the medulla oblongata are responsible for the implementation of complex reflexes:

• Protective: sneezing, blinking, coughing, producing tears, vomiting
• Digestive: swallowing, sucking, chewing
• Autonomic: salivation, respiration, regulation of vascular function
• Statokinetic: rearrangement muscular system to create a pose appropriate to the moment
• Static: control of skeletal muscle tone to maintain a certain body position

The medulla oblongata provides analysis of sensory sensations: taste and hearing. It analyzes incoming impulses and redirects them to the subcortical zone. Due to the structure of the vagus nerve nuclei, autonomic reflexes occur. All systems of the body are rebuilt to respond to a motor or secretory reaction of one internal organ.

Injury to this part of the brain can reduce the sensitivity of facial muscles, cause paralysis of the limbs, or completely immobilize a person.

Rear

This area of ​​the brain is adjacent to the medulla oblongata and consists of two parts: the pons and the cerebellum. The pons performs the same functions as the oblongata. Information flows that connect the brain and spinal cord pass through a bridge similar to a roller. In addition, the pons is the location of the nuclei of twelve pairs of nerves:

• Abductor
• Facial
• Wandering
• Trigeminal
• Auditory

In addition to transmitting information, the accumulation of pons fibers regulates blood pressure and regulates the reflex functions of the body: swallowing, coughing, sneezing. The posterior parts of the brain are responsible for coordinating human movements and the functioning of the vestibular apparatus.

Basically, the sequence of work of the muscular system depends on the cerebellum. It consists of two types of substance: gray and white, and is localized in the occipital part of the skull (fills the entire diamond-shaped fossa on the back of the head). The second name for the cerebellum is the small brain. Its task is to coordinate the activity of skeletal muscles. It is responsible for the smoothness, synchronization and clarity of movements.

Injury to the cerebellum affects the movement of not only the limbs, but also the tongue and eyelids. Damage to this part of the brain is characterized by negative changes:

• change in handwriting
• limb tremors
• changing speech from smooth to scanned
• slowing down voluntary movements
• spontaneous twitching eyeball(especially when looking away to the side)

With serious pathologies of the cerebellum, the human body is not able to maintain the position of the body. The full formation of the small brain in the first year of life is the key to successful coordination of movements in the future: the cerebellum develops intensively during this period.

The structure of the cerebellum contains two hemispheres, covered with a gray, furrowed substance.

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Average

The middle section of the brain is the main guard of the body's command center. At the subcortical level of the roof are the centers of hearing and vision. They look plate-shaped, consisting of four mounds. Superior colliculi work as a visual analyzer, the lower ones are responsible for auditory reactions.

The main purpose of the hills is to organize the “pay attention” reflex. For example, when the light is too bright, a person instinctively closes his eyes: this is the merit of the middle part of the brain. Interestingly, this same area of ​​the central nervous organ regulates the movement of the pupils: it dilates in the dark and constricts in the light of day.

The lower hills after receiving impulses from auditory nerves, develop a guard reaction: the person turns his head towards the source of irritation. The substantia nigra, which is part of the structure of the midbrain, provides fine movements of the fingers.

The structure and functions of the middle section played a leading role in the work of I.P. Pavlov on the study of reflexes. It is the four tubercles that are responsible for preparing the body to instantly respond to any event.

In addition to its guard function, the midbrain influences the activity of the flexor muscles and is involved in lifting, rotating, landing, and bending the body.

Intermediate

A small portion of the medulla is divided into three main sections.

Thalamus

He is the first to collect information about pain, feelings of pleasant and unpleasant. The thalamus contains the thirst and hunger centers. Its purpose: rapid collection and analysis of various sensory perceptions (except smell) and transmission along nerve pathways to the cerebral hemispheres.

Hypothalamus

The subcortical center is endowed with enormous powers:

1. Thermoregulation - ensuring and maintaining optimal body temperature.
2. Control of secretion of sweat glands.
3. Regulation of intestinal motility.
4. Control of heart rate, breathing, blood pressure.
5. Formation and maintenance of sleep and wakefulness.

The hypothalamus is responsible for human sexual behavior and is the first to respond to stressful situations. By interacting with the pituitary gland, it stimulates the production of hormones that help the body adapt to stress.

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Pituitary

A tiny area of ​​the brain plays a key role in the secretion of most hormones: growth hormone (somatotropin), oxytocin (contraction smooth muscles intestines, bladder), prolactin (production breast milk), thyroid-stimulating hormone. In addition, the pituitary gland synthesizes sex hormones in both women and men.

The diencephalon includes the epithalamus and pineal gland: small lobes that regulate the body’s adaptation to changes in biological rhythms.

Telencephalon: cerebral hemispheres

The most massive section of the brain, occupying about 80% of the space of the cranium. The two hemispheres are fused together by the corpus callosum. The complex structural layer covering the telencephalon is called the cortex. In the course of medical research, it was discovered that the presence of a cortex and developed hemispheres distinguishes the human mind from animals.

The right hemisphere controls left side human body, the left - vice versa. Left hemisphere is more guided by reason; in the right, emotions and sensuality predominate. divides the hemispheres into four lobes, each of which has its own purpose in the mental and physical development body:

• The frontal lobe provides control and management of human behavior. This area includes planning, reasoning and judgment skills, and finding solutions to complex problems. The frontal lobe is responsible for learning and intelligence.
• Temporal lobe - the task of this area: transformation auditory sensations into visual images, to navigate tastes. The temporal region is responsible for the function of smell and the construction of speech communication.
• The parietal lobe is the main purpose of the lobe: analysis and understanding of the picture before the eyes, as well as the perception of objects by skin receptors, research pain.
• The occipital lobe is the center of visual analysis. Processing of information about shape, colors, and contours occurs in the visual lobe of the hemispheres.

All parts of the brain and their functions consume a lot of energy: 25% of the body’s total energy.

Understanding the intricacies of the central organ of the nervous system is extremely difficult. The process of studying parts of the brain does not stop for a minute: scientists continue to search for answers to still open questions.

Jun 6, 2016 Violetta Doctor

A person is a complex organism, consisting of many organs united into a single network, the work of which is regulated precisely and impeccably. The main function of regulating the work of the body is performed by the central nervous system(CNS). This is a complex system, including several organs and peripheral nerve endings and receptors. The most important organ of this system is the brain - a complex computing center responsible for the proper functioning of the entire organism.

General information about the structure of the brain

They have been trying to study it for a long time, but for all this time scientists have not been able to accurately and unambiguously answer the question 100% of what it is and how this organ works. Many functions have been studied, for some there are only guesses.

Visually, it can be divided into three main parts: the cerebellum and the cerebral hemispheres. However, this division does not reflect the full versatility of the functioning of this organ. In more detail, these parts are divided into departments responsible for certain functions of the body.

Oblong section

The human central nervous system is an inextricable mechanism. A smooth transitional element from the spinal segment of the central nervous system is the medulla oblongata. Visually, it can be represented in the form of a truncated cone with the base at the top or a small onion head with thickenings diverging from it - connecting to the intermediate section.

There are three different functions of the department - sensory, reflex and conductive. Its tasks include controlling the basic protective (gag reflex, sneezing, coughing) and unconscious reflexes (heartbeat, breathing, blinking, salivation, secretion of gastric juice, swallowing, metabolism). In addition, the medulla oblongata is responsible for such senses as balance and coordination of movements.

Midbrain

The next department responsible for communication with the spinal cord is the middle one. But the main function of this department is processing nerve impulses and adjusting performance hearing aid and the human visual center. After processing the received information, this formation sends impulse signals to respond to stimuli: turning the head towards the sound, changing body position in case of danger. TO additional functions This includes regulation of body temperature, muscle tone, and arousal.

The human midbrain is responsible for such an important ability of the body as sleep.

The middle section has a complex structure. There are 4 clusters of nerve cells - tubercles, two of which are responsible for visual perception, the other two for hearing. Nerve clusters are connected to each other and to other parts of the brain and spinal cord by the same nerve-conducting tissue, visually similar to legs. The total size of the segment does not exceed 2 cm in an adult.

Diencephalon

The department is even more complex in structure and functions. Anatomically, the diencephalon is divided into several parts: Pituitary gland. This is a small appendage of the brain that is responsible for the secretion essential hormones and regulation of the body's endocrine system.

Conventionally divided into several parts, each of which performs its own function:

• The adenohypophysis is a regulator of peripheral endocrine glands.
• The neurohypophysis is connected to the hypothalamus and accumulates the hormones it produces.

Hypothalamus

A small area of ​​the brain whose most important function is to control heart rate and blood pressure in blood vessels. Additionally, the hypothalamus is responsible for some of the emotional manifestations by producing the necessary hormones to suppress stressful situations. Another important function is the control of hunger, satiety and thirst. To top it off, the hypothalamus is the center of sexual activity and pleasure.

Epithalamus

The main task of this department is to regulate the daily biological rhythm. With the help of produced hormones, it influences the duration of sleep at night and normal wakefulness during the day. It is the epithalamus that adapts our body to the conditions of “daylight” and divides people into “night owls” and “larks”. Another task of the epithalamus is to regulate the body’s metabolism.

Thalamus

This formation is very important for a correct understanding of the world around us. It is the thalamus that is responsible for processing and interpreting impulses coming from peripheral receptors. This information processing center brings together data from the visual nerves, hearing aid, temperature receptors of the body, olfactory receptors and pain points.

Posterior

Like previous sections, the hindbrain includes subsections. The main part is the cerebellum, the second is the pons, which is a small cushion of nerve tissue that connects the cerebellum with other parts and the blood vessels that supply the brain.

Cerebellum

In its shape, the cerebellum resembles the cerebral hemispheres; it consists of two parts, connected by a “worm” - a complex of conductive nerve tissue. The main hemispheres consist of nerve cell nuclei, or “gray matter,” folded together to increase surface area and volume. This part is located in the occipital part of the skull and completely occupies its entire posterior fossa.

The main function of this department is coordination motor functions. However, the cerebellum does not initiate movements of the arms or legs - it only controls accuracy and clarity, the order of movements, motor skills and posture.

The second important task is the regulation of cognitive functions. These include: attention, understanding, awareness of language, regulation of the feeling of fear, sense of time, awareness of the nature of pleasure.

Large hemispheres of the brain

The bulk and volume of the brain is located in the terminal section or cerebral hemispheres. There are two hemispheres: the left - mostly responsible for analytical thinking and speech functions of the body, and the right - whose main task is abstract thinking and all processes associated with creativity and interaction with the outside world.

Structure of the telencephalon

The cerebral hemispheres are the main “processing unit” of the central nervous system. Despite their different “specializations,” these segments complement each other.

The cerebral hemispheres are a complex system of interaction between the nuclei of nerve cells and nerve-conducting tissues connecting the main areas of the brain. The upper surface, called the cortex, consists of a huge number of nerve cells. It is called gray matter. In the light of general evolutionary development, the cortex is the youngest and most developed formation of the central nervous system and has reached its highest development in humans. It is she who is responsible for the formation of higher neuropsychic functions and complex forms of human behavior. To increase the usable area, the surface of the hemispheres is assembled into folds or convolutions. The inner surface of the cerebral hemispheres consists of white matter - processes of nerve cells responsible for conducting nerve impulses and communicating with the rest of the segments of the central nervous system.

In turn, each of the hemispheres is conventionally divided into 4 parts or lobes: occipital, parietal, temporal and frontal.

Occipital lobes

The main function of this conditional part is the processing of neural signals coming from the visual centers. It is here that the usual concepts of color, volume and other three-dimensional properties of a visible object are formed from light stimuli.

Parietal lobes

This segment is responsible for the occurrence of pain and processing signals from the body's thermal receptors. That's it for them general work ends.

The parietal lobe of the left hemisphere is responsible for structuring information packages, allowing you to operate with logical operators, count and read. Also, this area forms awareness of the holistic structure of the human body, determination of the right and left parts, coordination of individual movements into a single whole.

The right one is engaged in generalizing information flows that are generated by the occipital lobes and the left parietal lobe. In this area a common three-dimensional picture perception environment, spatial position and orientation, calculation of perspective.

Temporal lobes

This segment can be compared to a computer’s “hard drive” – a long-term storage of information. This is where all the memories and knowledge of a person collected over a lifetime are stored. The right temporal lobe is responsible for visual memory - image memory. Left - all concepts and descriptions of individual objects are stored here, interpretation and comparison of images, their names and characteristics takes place.

As for speech recognition, both temporal lobes are involved in this procedure. However, their functions are different. If the left lobe is called upon to recognize semantic load words heard, then the right one interprets the intonation coloring and compares it with the speaker’s facial expressions. Another function of this part of the brain is the perception and decoding of neural impulses coming from the olfactory receptors of the nose.

Frontal lobes

This part is responsible for such properties of our consciousness as critical self-esteem, adequacy of behavior, awareness of the degree of meaninglessness of actions, and mood. General human behavior also depends on the proper functioning of the frontal lobes of the brain; violations lead to inappropriate and asocial actions. The process of learning, mastering skills, and acquiring conditioned reflexes depends on the proper functioning of this part of the brain. This also applies to the degree of activity and curiosity of a person, his initiative and awareness of decisions.

To systematize the functions of the GM, they are presented in the table:

Interaction of brain parts

In addition to the fact that each part of the brain has its own tasks, the holistic structure determines consciousness, character, temperament and other psychological characteristics of behavior. The formation of certain types is determined varying degrees influence and activity of one or another segment of the brain.

The first psychotype or choleric. The formation of this type of temperament occurs under the dominant influence of the frontal lobes of the cortex and one of the subsections of the diencephalon - the hypothalamus. The first generates determination and desire, the second section reinforces these emotions with the necessary hormones.

The characteristic interaction of the departments that determines the second type of temperament - sanguine - is the joint work of the hypothalamus and hippocampus (the lower part of the temporal lobes). The main function of the hippocampus is to maintain short-term memory and convert acquired knowledge into long-term memory. The result of such interaction is an open, inquisitive and interested type of human behavior.

Melancholic people are the third type of temperamental behavior. This variant is formed due to increased interaction between the hippocampus and another formation of the cerebral hemispheres - the amygdala. At the same time, the activity of the cortex and hypothalamus is reduced. The amygdala takes on the entire “blow” of exciting signals. But since the perception of the main areas of the brain is inhibited, the reaction to excitement is low, which in turn affects behavior.

In turn, by forming strong connections, the frontal lobe is able to set an active pattern of behavior. When the cortex of this area interacts with the tonsils, the central nervous system generates only highly significant impulses, while ignoring unimportant events. All this leads to the formation of a Phlegmatic model of behavior - a strong, purposeful person with an awareness of priority goals.