Brain - Financial Dictionary smart lab. The brain is the basis of the coordinated work of the body

The brain is the most important organ of the central nervous system, from the point of view of physiology, consisting of many nerve cells and processes. The body is a functional regulator responsible for the implementation of various processes that occur in the human body. At the moment, the study of the structure and functions continues, but even today it cannot be said that the organ has been studied at least half. The structural scheme is the most complex when compared with other organs of the human body.

The brain is made up of gray matter, which is a huge number of neurons. It is covered with three different shells. Weight varies from 1200 to 1400 g (for a small child - about 300-400 g). Contrary to popular belief, the size and weight of the body does not affect the intellectual abilities of the individual.

Intellectual abilities, erudition, efficiency - all this is ensured by high-quality saturation of brain vessels with useful microelements and oxygen, which the body receives exclusively with the help of blood vessels.

All parts of the brain should work as smoothly as possible and without disturbances, because the quality of this work will also depend on the standard of living of a person. In this area, increased attention is given to cells that transmit and form impulses.

Briefly, you can talk about the following important departments:

• Oblong. Regulates metabolism, analyzes nerve impulses, processes information received from the eyes, ears, nose and other sensory organs. This section contains the central mechanisms responsible for the formation of hunger and thirst. Separately, it is worth noting the coordination of movements, which is also in the area of ​​​​responsibility of the oblong section.
• Front. The structure of this department includes two hemispheres with a gray matter of the cortex. This zone is responsible for many important functions: higher mental activity, the formation of reflexes to stimuli, a person's demonstration of elementary emotions and the creation of characteristic emotional reactions, concentration of attention, activity in the field of cognition and thinking. It is also believed that pleasure centers are located here.
• Average. The composition includes the cerebral hemispheres, diencephalon. The department is responsible for the motor activity of the eyeballs, the formation of facial expressions on a person's face.
• Cerebellum. Acts as a connecting part between the bridge and the hindbrain, performs many important functions, which will be discussed later.
• Bridge. A large part of the brain that includes the centers of vision and hearing. It performs a huge number of functions: adjusting the curvature of the lens of the eye, the size of the pupils in various conditions, maintaining the balance and stability of the body in space, the formation of reflexes when exposed to stimuli to protect the body (cough, vomiting, sneezing, etc.), control over the heartbeat, the work of the cardiovascular system, assistance in the functioning of other internal organs.
• Ventricles (total 4 pieces). They are filled with cerebrospinal fluid, protect the most important organs of the central nervous system, create cerebrospinal fluid, stabilize the internal microclimate of the central nervous system, perform filtering functions, and control the circulation of cerebrospinal fluid.
• Wernicke and Broca centers (responsible for human speech abilities - speech recognition, its understanding, reproduction, etc.).
• brain stem. A prominent department, which is a fairly long formation that continues the spinal cord.

All departments as a whole are also responsible for biorhythms - this is one of the varieties of spontaneous background electrical activity. You can examine in detail all the lobes and departments of the organ using the frontal cut.

It is widely believed that we use the capacity of our brain by 10 percent. This is a delusion, because those cells that do not participate in functional activity simply die off. Therefore, the brain is used by us at 100%.

telencephalon

It is customary to include hemispheres with a unique structure, a huge number of convolutions and furrows in the composition of the telencephalon. Taking into account the asymmetry of the brain, each hemisphere includes a nucleus, a mantle, and an olfactory brain.

The hemispheres are presented as a multifunctional system with many levels, which includes the vault and the corpus callosum, connecting the hemispheres to each other. The levels of this system are: cortex, subcortex, frontal, occipital, parietal lobes. The frontal is necessary to ensure the normal motor activity of the human limbs.

diencephalon

The specificity of the structure of the brain affects the structure of its main departments. For example, the diencephalon also consists of two main parts: ventral and dorsal. The dorsal section includes the epithalamus, thalamus, metathalamus, and the ventral - the hypothalamus. In the structure of the intermediate zone, it is customary to distinguish between the epiphysis and the epithalamus, which regulate the body's adaptation to a change in biological rhythm.

The thalamus is one of the most important parts, because it is necessary for a person to process and regulate various external stimuli and the ability to adapt to changing environmental conditions. The main purpose is the collection and analysis of various sensory perceptions (with the exception of smell), the transmission of the corresponding impulses to large hemispheres.

Considering the structural features and functions of the brain, it is worth noting the hypothalamus. This is a special separate subcortical center, fully focused on working with various vegetative functions of the human body. The impact of the department on internal organs and systems is carried out with the help of the central nervous system and endocrine glands. The hypothalamus also performs the following characteristic functions:

• creation and maintenance of sleep and wakefulness patterns in everyday life.
• thermoregulation (maintaining normal body temperature);
• regulation of heart rate, respiration, pressure;
• control of the sweat glands;
• regulation of intestinal motility.

Also, the hypothalamus provides the initial human response to stress, is responsible for sexual behavior, so it can be characterized as one of the most important departments. When working together with the pituitary gland, the hypothalamus has a stimulating effect on the formation of hormones that help us adapt the body to a stressful situation. Closely related to the work of the endocrine system.

The pituitary gland is relatively small (about the size of a sunflower seed), but is responsible for the production of a huge number of hormones, including the synthesis of sex hormones in men and women. It is located behind the nasal cavity, ensures normal metabolism, controls the functioning of the thyroid, sex glands, and adrenal glands.

The brain, being in a calm state, consumes a huge amount of energy - about 10-20 times more than muscles (relative to their mass). Consumption is within 25% of all available energy.

midbrain

The midbrain has a relatively simple structure, small size, includes two main parts: the roof (located centers of hearing and vision, located in the subcortical part); legs (accommodate pathways in themselves). It is also customary to include black matter and red nuclei in the structure of the dress.

The centers of the subcortex, which are part of this department, work to maintain the normal functioning of the centers of hearing and vision. Also located here are the nuclei of the nerves that provide the work of the muscles of the eyes, the temporal lobes that process various auditory sensations, turning them into sound images familiar to humans, and the temporo-parietal node.

The following functions of the brain are also distinguished: control (together with the oblong section) of emerging reflexes when exposed to a stimulus, assistance in orientation in space, the formation of an appropriate response to stimuli, and rotation of the body in the desired direction.

The gray matter in this part is a high concentration of nerve cells that form the nerve nuclei inside the skull.

The brain develops actively between the ages of two and eleven. The most effective method of improving your intellectual abilities is to engage in unfamiliar activities.

Medulla

An important department of the central nervous system, which in various medical descriptions is called the bulb. It is located between the cerebellum, bridge, dorsal region. The bulbus, being part of the central nervous system, is responsible for the functioning of the respiratory system, the regulation of blood pressure, which is vital for a person.

In this regard, if this department is damaged in some way (mechanical damage, pathologies, strokes, etc.), then the probability of death of a person is high.

The most important functions of the oblongata are:

• Joint work with the cerebellum to ensure balance, coordination of the human body.
• The department includes the vagus nerve with autonomic fibers, which contributes to the functioning of the digestive and cardiovascular systems, blood circulation.
• Ensuring the swallowing of food and liquids.
• Presence of coughing and sneezing reflexes.
• Regulation of the work of the respiratory system, blood supply to individual organs.

The medulla oblongata, whose structure and functions differ from the spinal cord, has many common structures with it.

The brain contains about 50-55% fat, and according to this indicator, it is far ahead of the rest of the organs of the human body.

Cerebellum

From the point of view of anatomy in the cerebellum, it is customary to distinguish between the posterior and anterior edges, the lower and upper surfaces. In this zone there is a middle section and hemispheres, divided into three lobes by furrows. It is one of the most important brain structures.

The main function of this department is the regulation of the skeletal muscles. Together with the cortical layer, the cerebellum takes part in the coordination of voluntary movements, which occurs due to the presence of connections between the department and receptors that are embedded in skeletal muscles, tendons, and joints.

The cerebellum also affects the regulation of body balance during human activity and during walking, which is carried out in conjunction with the vestibular apparatus of the semicircular canals of the inner ear, which transmit information to the central nervous system about the position of the body and head in space. This is one of the most important functions of the brain.

The cerebellum provides coordination of skeletal muscle movements with the help of conductive fibers that run from it to the anterior horns of the spinal cord to the place where the peripheral motor nerves of skeletal muscles begin.

Tumors can form on the cerebellum as a result of a cancerous lesion of the department. The disease is diagnosed with

The central nervous system is that part of the body responsible for our perception of the outside world and ourselves. It regulates the work of the whole body and, in fact, is the physical substratum of what we call "I". The main organ of this system is the brain. Let's look at how the parts of the brain are arranged.

Functions and structure of the human brain

This organ is predominantly made up of cells called neurons. These nerve cells produce electrical impulses that keep the nervous system working.

The work of neurons is provided by cells called neuroglia - they make up almost half of the total number of cells in the central nervous system.

Neurons, in turn, consist of a body and processes of two types: axons (transmitting impulse) and dendrites (receiving impulse). The bodies of nerve cells form a tissue mass, which is commonly called gray matter, and their axons are woven into nerve fibers and represent white matter.

Over the course of evolution, the brain has become one of the most important organs in the entire body. Occupying only one fiftieth of the total body weight, it consumes a fifth of all oxygen entering the blood.

To protect it, nature has formed a whole arsenal of various means. Outside, the parts of the brain are protected by the cranium, under which there are three more shells of the brain:

1. Solid. It is a thin film, one side adjacent to the bone tissue of the skull, and the other directly to the cortex.
2. Soft. It consists of loose tissue and tightly envelops the surface of the hemispheres, going into all the cracks and furrows. Its function is the blood supply to the body.
3. Gossamer. It is located between the first and second shells and exchanges CSF (cerebrospinal fluid). Liquor is a natural shock absorber that protects the brain from damage during movement.

Next, let's take a closer look at how the human brain works. According to morphological and functional characteristics, the brain is also divided into three parts. The lowest section is called diamond-shaped. Where the rhomboid part begins, the spinal cord ends - it passes into the oblong and posterior (Varoli bridge and cerebellum).

This is followed by the midbrain, uniting the lower parts with the main nerve center - the anterior section. The latter includes the terminal (large hemispheres) and diencephalon. The key functions of the cerebral hemispheres are the organization of higher and lower nervous activity.

telencephalon

This part has the largest volume (80%) compared to the rest. It consists of two cerebral hemispheres, the corpus callosum that connects them, and the olfactory center.

The large hemispheres of the brain, left and right, are responsible for the formation of all thought processes. Here is the highest concentration of neurons and the most complex connections between them are observed. In the depth of the longitudinal groove that divides the hemispheres, there is a dense concentration of white matter - the corpus callosum. It consists of complex plexuses of nerve fibers that intertwine various parts of the nervous system.

Within the white matter are clusters of neurons called the basal ganglia. The close location to the "traffic junction" of the brain allows these formations to regulate muscle tone and carry out instant reflex-motor reactions. In addition, the basal ganglia are responsible for the formation and operation of complex automatic actions, partially repeating the functions of the cerebellum.

Cortex

This small superficial layer of gray matter (up to 4.5 mm) is the youngest formation in the central nervous system. It is the cerebral cortex that is responsible for the work of the higher nervous activity of a person.

Studies have made it possible to determine which areas of the cortex were formed in the course of evolutionary development relatively recently, and which were still present in our prehistoric ancestors:

• neocortex - a new outer part of the cortex, which is its main part;
• archicortex - an older formation responsible for the instinctive behavior and emotions of a person;
• The paleocortex is the most ancient area involved in the control of autonomic functions. In addition, it helps to maintain the internal physiological balance of the body.

Despite the seemingly small volume, the cerebral cortex has an area of ​​​​about four square meters.

This is possible thanks to the convolutions and furrows, which, in addition, also divide the hemispheres into lobes, each of which has different functions:

frontal lobes

The largest lobes of the cerebral hemispheres responsible for complex motor functions. In the frontal lobes of the brain, voluntary movements are planned, and speech centers are also located here. It is in this part of the cortex that volitional control of behavior is exercised. In case of damage to the frontal lobes, a person loses control over his actions, behaves antisocially and simply inadequately.

Occipital lobes

Closely related to the visual function, they are responsible for the processing and perception of optical information. That is, they turn the entire set of those light signals that enter the retina into meaningful visual images.

parietal lobes

Conduct spatial analysis and process most of the sensations (touch, pain, “muscle feeling”). In addition, it contributes to the analysis and integration of various information into structured fragments - the ability to feel one's own body and its sides, the ability to read, count and write.

temporal lobes

In this department, the analysis and processing of audio information takes place, which provides the function of hearing, the perception of sounds. The temporal lobes are involved in recognizing the faces of different people, as well as facial expressions and emotions. Here, information is structured for permanent storage, and thus long-term memory is realized.

In addition, the temporal lobes contain speech centers, damage to which leads to an inability to perceive spoken language.

insular lobe

It is considered responsible for the formation of consciousness in a person. In moments of empathy, empathy, listening to music and the sounds of laughter and crying, there is an active work of the insular lobe. Here, the processing of feelings of disgust for dirt and unpleasant odors, including imaginary stimuli, takes place.

diencephalon

The diencephalon serves as a kind of filter for neural signals - it receives all the incoming information and decides where which should go. Consists of lower and posterior parts (thalamus and epithalamus). In this department, the endocrine function is also realized, i.e. hormonal exchange.

The lower part consists of the hypothalamus. This small dense bundle of neurons has a tremendous impact on the entire body. In addition to regulating body temperature, the hypothalamus controls the sleep-wake cycles. It also releases hormones that are responsible for feelings of hunger and thirst. As the pleasure center, the hypothalamus regulates sexual behavior.

It is also directly related to the pituitary gland and translates nervous activity into endocrine. The functions of the pituitary gland, in turn, are to regulate the work of all the glands of the body. Electrical signals go from the hypothalamus to the pituitary gland of the brain, “ordering” the production of which hormones to start and which to stop.

The diencephalon also includes:

• Thalamus - it is this part that performs the functions of a "filter". Here, the signals coming from the visual, auditory, taste and tactile receptors undergo primary processing and are distributed to the relevant departments.
• Epithalamus - produces the hormone melatonin, which regulates wakefulness cycles, participates in the process of puberty, controls emotions.

midbrain

First of all, it regulates auditory and visual reflex activity (constriction of the pupil in bright light, turning the head to a source of loud sound, etc.). After processing in the thalamus, the information goes to the midbrain.

Here it is further processed and the process of perception begins, the formation of a meaningful sound and optical image. In this department, the movement of the eyes is synchronized and the work of binocular vision is provided.

The midbrain includes the peduncles and the quadrigemina (two auditory and two visual hillocks). Inside is the cavity of the midbrain, which unites the ventricles.

Medulla

This is an ancient formation of the nervous system. The functions of the medulla oblongata are to provide breathing and heartbeat. If this area is damaged, then the person dies - oxygen stops flowing into the blood, which the heart no longer pumps. In the neurons of this department, such protective reflexes as: sneezing, blinking, coughing and vomiting begin.

The structure of the medulla oblongata resembles an elongated bulb. Inside it contains the nuclei of gray matter: the reticular formation, the nuclei of several cranial nerves, as well as neuronal nodes. The pyramid of the medulla oblongata, consisting of pyramidal nerve cells, performs a conductive function, uniting the cortex of the hemispheres and the spinal region.

The most important centers of the medulla oblongata:

• breathing regulation
• regulation of blood circulation
• regulation of a number of functions of the digestive system

Hindbrain: pons and cerebellum

The structure of the hindbrain includes the pons and the cerebellum. The function of the bridge is very similar to its name, since it consists mainly of nerve fibers. The bridge of the brain is, in fact, a “highway” through which signals go from the body to the brain, and impulses from the nerve center to the body. On the ascending paths, the bridge of the brain passes into the midbrain.

The cerebellum has a much wider range of possibilities. The function of the cerebellum is to coordinate body movements and maintain balance. Moreover, the cerebellum not only regulates complex movements, but also contributes to the adaptation of the motor apparatus in various disorders.

For example, experiments using an invertoscope (special glasses that flip the image of the surrounding world) showed that it is the functions of the cerebellum that are responsible for the fact that when the device is worn for a long time, a person not only begins to navigate in space, but also sees the world correctly.

Anatomically, the cerebellum repeats the structure of the cerebral hemispheres. Outside it is covered with a layer of gray matter, under which there is an accumulation of white.

limbic system

The limbic system (from the Latin word limbus - edge) is a set of formations encircling the upper part of the trunk. The system includes the olfactory centers, the hypothalamus, the hippocampus, and the reticular formation.

The main functions of the limbic system are the adaptation of the body to changes and the regulation of emotions. This education contributes to the creation of lasting memories, through associations between memory and sensory experiences. The close connection between the olfactory tract and the emotional centers is why smells evoke such strong and distinct memories for us.

If you list the main functions of the limbic system, then it is responsible for the following processes:

1. Smell
2. Communication
3. Memory: short term and long term
4. restful sleep
5. Efficiency of departments and bodies
6. Emotions and motivational component
7. Intellectual activity
8. Endocrine and autonomic
9. Partially involved in the formation of food and sexual instinct
   

Medulla can be confused with the functions of the spinal cord! In the nuclei of gray matter (cluster of dendrites) are protective reflex centers- blinking and vomiting, coughing, sneezing, as well as the medulla oblongata allows you to inhale and exhale, secrete saliva (on automatism, we cannot control this reflex), swallow, secrete gastric juice - also on automatism. The medulla oblongata performs reflex and conductive functions.

Bridge responsible for the movement of the eyeballs and facial expressions.

Cerebellum responsible for the coordination of movement.

midbrain responsible for the clarity of vision and hearing. It regulates the size of the pupil, the curvature of the lens. Regulates muscle tone. It contains the centers of the orienting reflex

forebrain- the largest part of the brain, which is divided into two halves.

1) diencephalon, which is divided into three parts:

a) Top

b) The lower one (aka the hypotholamus) - regulates the metabolism and energy, that is: fasting - saturation, thirst - quenching.

c) Central (thalamus) - here the first processing of information from the sense organs takes place.

2) Large hemispheres brain

a) Left hemisphere - right-handers have speech centers here, and the left hemisphere is responsible for the movement of the right leg, right arm, etc.

b) The right hemisphere - for right-handed people, the situation is perceived here as a whole (at what distance is the fence, what volume is it, etc.), and is also responsible for the movement of the left leg, left arm, etc.

Occipital lobe- location of the visual zones formed by neurons.

temporal lobe- location of auditory zones.

parietal lobe- Responsible for musculoskeletal sensitivity.

The inner surface of the temporal lobes is the olfactory and gustatory zones.

frontal lobes front part - active behavior.

Ahead of the central gyrus is the motor zone.

autonomic nervous system. According to its structure and properties autonomic nervous system (ANS) is different from somatic(SNA) the following features:

1. The ANS centers are located in different parts of the CNS: in the middle and oblong parts of the brain, sternolumbar and sacral segments of the spinal cord. Nerve fibers extending from the nuclei of the middle and medulla oblongata and from the sacral segments of the spinal cord form parasympathetic division of the ANS. Fibers emerging from the nuclei of the lateral horns of the sternolumbar segments of the spinal cord form sympathetic division of the ANS.

2. Nerve fibers, leaving the CNS, do not reach the innervated organ, but are interrupted and come into contact with the dendrite of another nerve cell, the nerve fiber of which already reaches the innervated organ. In places of contact, accumulations of bodies of nerve cells form nodes, or ganglia, of the ANS. Thus, the peripheral part of the motor sympathetic and parasympathetic nerve pathways is built from two consecutively following each other neurons (Fig. 13.3). The body of the first neuron is located in the central nervous system, the body of the second is in the autonomic ganglion (ganglion). The nerve fibers of the first neuron are called preganglionic mi, second -postganglionic

.

Fig.3. Scheme of the reflex arc of somatic (a) and vegetative (6) reflexes: 1 - receptor; 2 - sensitive nerve; 3 - central nervous system; 4 - motor nerve; 5 -working body -muscle, gland; TO - contact (insert) neuron; G - vegetative ganglion; 6.7 - pre- and postganglionic nerve fibers.

3. Ganglia of the sympathetic division of the ANS are located on both sides of the spine, forming two symmetrical chains of nerve nodes connected to each other. The ganglia of the parasympathetic division of the ANS are located in the walls of the innervated organs or near them. Therefore, in the parasympathetic division of the ANS, the post-ganglionic fibers, in contrast to the sympathetic ones, are short.

4. The nerve fibers of the ANS are 2-5 times thinner than the fibers of the SNS. Their diameter is 0.002-0.007 mm, therefore, the speed of excitation through them is lower than through SNS fibers, and reaches only 0.5-18 m/s (for SNS fibers - 30-120 m/s). Most of the internal organs have a dual innervation, i.e., nerve fibers of both the sympathetic and parasympathetic divisions of the ANS are suitable for each of them. They have the opposite effect on the work of organs. So, excitation of sympathetic nerves speeds up the rhythm of contractions of the heart muscle, narrows the lumen of blood vessels. The opposite effect is associated with the excitation of the parasympathetic nerves. The meaning of the double innervation of the internal organs lies in the involuntary contractions of the smooth muscles of the walls. In this case, reliable regulation of their activity can only be ensured by double innervation, which has the opposite effect.

The brain is part of the central nervous system, the main regulator of all vital functions of the body. As a result of his defeat, severe diseases occur. The brain contains 25 billion neurons that make up the cerebral gray matter. The brain is covered by three membranes - hard, soft and arachnoid located between them, through the channels of which cerebrospinal fluid (CSF) circulates. Liquor is a kind of hydraulic shock absorber. The brain of an adult male weighs an average of 1375 g, women - 1245 g. However, this does not mean that in men it is better developed. Sometimes the weight of the brain can reach 1800 g.

Structure

The brain consists of 5 main sections: the final, diencephalon, middle, hindbrain and medulla oblongata. The telencephalon makes up 80% of the total mass of the brain. It stretched from the frontal bone to the occipital. The telencephalon consists of two hemispheres, in which there are many furrows and convolutions. It is divided into several lobes (frontal, parietal, temporal and occipital). Distinguish between the subcortex and the cerebral cortex. The subcortex consists of subcortical nuclei that regulate various body functions. The brain is located in three cranial fossae. The large hemispheres occupy the anterior and middle fossa, and the posterior fossa - the cerebellum, under which the medulla oblongata is located.

Functions

The functions of different parts of the brain are different.

telencephalon

There are about 10 billion neurons in the gray cortex. They make up only a 3 mm layer, but their nerve fibers are branched like a network. Each neuron can have up to 10,000 contacts with other neurons. Part of the nerve fibers through the corpus callosum of the large brain connects the right and left hemispheres. Neurons make up the gray matter and fibers make up the white matter. Inside the cerebral hemispheres, between the frontal lobes and the diencephalon, there are accumulations of gray matter. These are the basal ganglia. Ganglia are clusters of neurons that transmit information.

diencephalon

The diencephalon is divided into ventral (hypothalamus) and dorsal (thalamus, metathalamus, epithalamus) parts. The thalamus is the mediator in which all stimuli received from the outside world converge and are directed to the cerebral hemispheres in such a way that the body can adequately adapt to a constantly changing environment. The hypothalamus is the main subcortical center for the regulation of the autonomic functions of the body.

midbrain

It extends from the anterior edge of the pons to the optic tracts and papillary bodies. It consists of the legs of the large brain and the quadrigemina. All ascending paths to the cerebral cortex and cerebellum and descending ones, carrying impulses to the medulla oblongata and spinal cord, pass through the midbrain. It is important for processing nerve impulses from visual and auditory receptors.

Cerebellum and bridge

The cerebellum is located in the occipital region behind the medulla oblongata and the pons. It consists of two hemispheres and a worm between them. The surface of the cerebellum is dotted with furrows. The cerebellum is involved in the coordination of complex motor acts.

Ventricles of the brain

The lateral ventricles are located in the forebrain hemispheres. The third ventricle is located between the visual tubercles and is connected to the fourth ventricle, which communicates with the subarachnoid space. Liquor, located in the ventricles, circulates in the arachnoid mater.

Large (terminal) brain functions

Thanks to the work of the brain, a person can think, feel, hear, see, touch, move. The large (final) brain controls all vital processes occurring in the human body, and is also the "receptacle" of all our intellectual abilities. From the world of animals, a person, first of all, is distinguished by developed speech and the ability to abstract thinking, i.e. the ability to think in moral or logical categories. Only in the human mind can various ideas arise, for example, political, philosophical, theological, artistic, technical, creative.

In addition, the brain regulates and coordinates the work of all human muscles (both those that a person can control by willpower and those that do not depend on the will of a person, for example, the heart muscle). Muscles receive a series of impulses from the central nervous system, to which the muscles respond with a contraction of a certain strength and duration. Impulses enter the brain from various sense organs, causing the necessary reactions, for example, turning the head in the direction from which the noise is heard.

The left brain hemisphere controls the right half of the body, and the right hemisphere controls the left. The two hemispheres complement each other.

The brain resembles a walnut; three large sections are distinguished in it - the trunk, subcortical section and the cerebral cortex. The total surface of the cortex increases due to numerous furrows, which divide the entire surface of the hemisphere into convex convolutions and lobes. Three main sulci - central, lateral and parietal-occipital - divide each hemisphere into four lobes: frontal, parietal, occipital and temporal. Separate areas of the cerebral cortex have different functional significance. Impulses from receptor formations enter the cerebral cortex. Each peripheral receptor apparatus in the cortex corresponds to an area called the cortical nucleus of the analyzer. An analyzer is an anatomical and physiological formation that provides the perception and analysis of information about phenomena occurring in the environment and (or) inside the human body, and forms sensations specific to a particular analyzer (for example, pain, visual, auditory analyzer). The areas of the cortex where the cortical nuclei of the analyzers are located are called the sensory zones of the cerebral cortex. The motor zone of the cerebral cortex interacts with the sensory zones, and when it is stimulated, movement occurs. This can be shown by a simple example: when a candle flame approaches, the pain and heat receptors of the fingers begin to send signals, then the neurons of the corresponding analyzer identify these signals as pain caused by a burn, and the muscles are “ordered” to withdraw the hand.

Association zones

Associative zones are functional zones of the cerebral cortex. They connect incoming sensory information with previously received and stored in memory, and also compare information received from different receptors. Sensory signals are comprehended, interpreted and, if necessary, transmitted to the motor area associated with it. Thus, associative zones are involved in the processes of thinking, memorization and learning.

Lobes of the telencephalon

The telencephalon is divided into the frontal, occipital, temporal and parietal lobes. In the frontal lobe there are zones of intellect, the ability to concentrate and motor zones; in the temporal - auditory zones, in the parietal - zones of taste, touch, spatial orientation, and in the occipital - visual zones.

Speech zone

Extensive damage to the left temporal lobe, for example, as a result of serious head injuries and various diseases, as well as after a stroke, is usually accompanied by sensory and motor speech disorders.

The telencephalon is the youngest and most developed part of the brain, which determines the ability of a person to think, feel, speak, analyze, and also controls all the processes occurring in the body. The functions of other parts of the brain, first of all, include the control and transmission of impulses, many vital functions - they regulate hormone metabolism, metabolism, reflexes, etc.

The brain needs oxygen to function properly. For example, if cerebral circulation is disturbed during cardiac arrest or a carotid artery injury, then after a few seconds the person loses consciousness, and after 2 minutes brain cells begin to die.

Functions of the diencephalon

The visual tubercle (thalamus) and hypothalamus (hypothalamus) are parts of the diencephalon. Impulses from all receptors of the body enter the nuclei of the thalamus. The received information in the thalamus is processed and sent to the cerebral hemispheres. The thalamus connects to the cerebellum and the so-called limbic system. The hypothalamus regulates the autonomic functions of the body. The influence of the hypothalamus is carried out through the nervous system and endocrine glands. The hypothalamus is also involved in the regulation of the functions of many endocrine glands and metabolism, as well as in the regulation of body temperature and the activity of the cardiovascular and digestive systems.

limbic system

The limbic system plays an important role in shaping human emotional behavior. The limbic system includes nerve formations located on the median side of the telencephalon. This area has not yet been fully explored. It is assumed that the limbic system and the hypothalamus that it controls are responsible for many of our feelings and desires, for example, thirst and hunger, fear, aggressiveness, and sexual desire arise under their influence.

Functions of the brain stem

The brain stem is a phylogenetically ancient part of the brain, consisting of the midbrain, hindbrain, and medulla oblongata. In the midbrain there are primary visual and auditory centers. With their participation, orienting reflexes to light and sound are carried out. In the medulla oblongata are centers for the regulation of respiration, cardiovascular activity, the functions of the digestive organs, and metabolism. The medulla oblongata is involved in the implementation of such reflex acts as chewing, sucking, sneezing, swallowing, vomiting.

Functions of the cerebellum

The cerebellum controls body movements. Impulses come to the cerebellum from all receptors that are irritated during body movements. The function of the cerebellum may be affected by the ingestion of alcohol or other substances that cause dizziness. Therefore, under the influence of intoxication, people are not able to coordinate their movements normally. In recent years, there is more and more evidence that the cerebellum is also important in human cognitive activity.

cranial nerves

In addition to the spinal cord, twelve cranial nerves are also very important: pairs I and II - olfactory and optic nerves; III, IV VI pairs - oculomotor nerves; V pair - trigeminal nerve - innervates the masticatory muscles; VII - facial nerve - innervates the facial muscles, also contains secretory fibers to the lacrimal and salivary glands; VIII pair - vestibulocochlear nerve - connects the organs of hearing, balance and gravity; IX pair - glossopharyngeal nerve - innervates the pharynx, its muscles, parotid gland, taste buds of the tongue; X pair - the vagus nerve - is divided into a number of branches that innervate the lungs, heart, intestines, regulate their functions; XI pair - accessory nerve - innervates the muscles of the shoulder girdle. As a result of the fusion of the spinal nerves, the XII pair is formed - the hypoglossal nerve - innervates the muscles of the tongue and the hypoglossal apparatus.

The human brain weighs approximately from 1020 to 1970. The brain of men weighs a little more than the brain of the beautiful half of humanity. Despite the fact that the brain is absolutely insensitive to pain, it consists of a great many nerve cells that are interconnected. The cerebrum consists of significant five sections - the forebrain (left and right hemisphere), the main medulla oblongata, the posterior (bridge and cerebellum), the midbrain and diencephalon. All these departments are combined into three large parts: the two hemispheres of the cerebrum, the active cerebellum and the dominant brain stem.

The most important cerebral hemispheres

The left and right hemispheres are like two completely different poles. One hemisphere (left) specializes in logical and abstract thinking. The second hemisphere (right) deals with concrete and imaginative thinking. Scientists have proven that a person whose work is dominated by the left hemisphere has a more optimistic attitude towards life and is always in a good mood. The cerebral hemispheres account for about 70% of the total brain mass. The left and right hemisphere consists of the frontal, temporal, parietal and occipital parts. In the frontal part, there are processes responsible for motor activity. The parietal zone is responsible for bodily sensations. The temporal parts are the areas of the brain that are responsible for hearing, speech and memory, but the occipital part is responsible for vision.

The cerebellum, without the full-fledged work of which is nowhere

The cerebellum is an equally important part of the brain, thanks to which a person can feel great while in an upright state. The cerebellum is located under the occipital lobes of the left and right hemispheres. The cerebellum helps a person to form all the skills that are necessary for a full daily life. So, the main functions of the cerebellum are the perfect coordination of movements and the most important distribution of muscle tone. The cerebellum weighs approximately 120-150 g.

Brain stem. What is the task?

The brain stem is a direct continuation of the spinal cord. The brain stem looks like an extended formation. This part includes the medulla oblongata, the pons, and the midbrain. In this zone, many scientists also include the cerebellum, the reticular formation, and the hypothalamus. The brain stem controls involuntary behavior (coughing, sneezing, and other processes) as well as behavior that is under voluntary control (breathing, sleeping, eating, and so on).