The brain is the main controlling organ of the central nervous system(CNS), has been working on the study of its structure and functions for more than 100 years a large number of specialists in various fields, such as psychiatry, medicine, psychology and neurophysiology. Despite a good study of its structure and components, there are still many questions about the work and processes that take place every second.
The brain belongs to the central nervous system and is located in the cranial cavity. Outside, it is reliably protected by the bones of the skull, and inside it is enclosed in 3 shells: soft, cobweb and hard. Between these membranes circulates cerebrospinal fluid - cerebrospinal fluid, which serves as a shock absorber and prevents concussion of this organ in case of minor injuries.
The human brain is a system consisting of interconnected departments, each part of which is responsible for performing specific tasks.
To understand the functioning, it is not enough to briefly describe the brain, therefore, in order to understand how it works, you first need to study its structure in detail.
What is the brain responsible for
This organ, like the spinal cord, belongs to the central nervous system and plays the role of an intermediary between the environment and the human body. With its help, self-control, reproduction and memorization of information, figurative and associative thinking, and other cognitive psychological processes.
According to the teachings of Academician Pavlov, the formation of thought is a function of the brain, namely the cerebral cortex, which are the highest organs nervous activity. The cerebellum is responsible for different types of memory, limbic system and some areas of the cerebral cortex, but since memory is different, it is impossible to single out any particular area responsible for this function.
It is responsible for managing the vegetative vital functions of the body: respiration, digestion, endocrine and excretory systems, body temperature control.
To answer the question of what function the brain performs, first you should conditionally divide it into sections.
Experts distinguish 3 main parts of the brain: anterior, middle and rhomboid (rear) section.
- The anterior one performs higher psychiatric functions, such as the ability to know, the emotional component of a person’s character, his temperament and complex reflex processes.
- The middle one is responsible for sensory functions and processing of information received from the organs of hearing, vision and touch. The centers located in it are able to regulate the degree of pain, since the gray matter, under certain conditions, is able to produce endogenous opiates that increase or decrease the pain threshold. It also plays the role of a conductor between the cortex and the underlying sections. This part controls the body through various innate reflexes.
- Rhomboid or posterior section, responsible for muscle tone, coordination of the body in space. Through it, purposeful movement of various muscle groups is carried out.
The structure of the brain cannot be simply briefly described, since each of its parts includes several departments, each of which performs certain functions.
What does the human brain look like
Brain anatomy is a relatively young science, since long time was banned due to laws prohibiting the autopsy and examination of organs and the head of a person.
The study of the topographic anatomy of the brain region in the head area is necessary for accurate diagnosis and successful treatment of various topographic anatomical disorders, for example: skull injuries, vascular and oncological diseases. To imagine what a human GM looks like, first you need to study them appearance.
In appearance, GM is a gelatinous mass of yellowish color, enclosed in a protective shell, like all organs. human body They are 80% water.
The large hemispheres occupy practically the volume of this organ. They are covered with gray matter or bark - supreme body neuropsychic activity of a person, and inside - from white matter, consisting of processes of nerve endings. The surface of the hemispheres complex pattern, due to going to different sides convolutions and ridges between them. According to these convolutions, it is customary to divide them into several departments. It is known that each of the parts performs certain tasks.
In order to understand what the human brain looks like, it is not enough to examine their appearance. There are several study methods that help to study the inside of the brain in a section.
- Sagittal section. It is a longitudinal section that passes through the center of the human head and divides it into 2 parts. It is the most informative research method, it is used to diagnose various diseases of this organ.
- The frontal section of the brain looks like a transverse section large shares and allows you to view the fornix, hippocampus and corpus callosum, as well as the hypothalamus and thalamus, which control the vital functions of the body.
- Horizontal cut. Allows you to consider the structure of this organ in a horizontal plane.
The anatomy of the brain, as well as the anatomy of the human head and neck, is a rather difficult subject to study for a number of reasons, including the fact that their description requires studying a large amount of material and having good clinical training.
How the human brain works
Scientists around the world are studying the brain, its structure and functions that it performs. Much has been done in the last few years important discoveries, however, this part of the body remains not fully understood. This phenomenon is explained by the complexity of studying the structure and functions of the brain separately from the cranium.
In turn, the structure of brain structures determines the functions performed by its departments.
This organ is known to be nerve cells(neurons) interconnected by bundles of filamentous processes, but how does their interaction occur simultaneously as unified system is still unclear.
The diagram of the structure of the brain, based on the study of the sagittal section of the cranium, will help to explore the sections and membranes. In this figure, you can see the cortex, the medial surface of the cerebral hemispheres, the structure of the trunk, cerebellum and the corpus callosum, which consists of a roller, trunk, knee and beak.
The GM is reliably protected from the outside by the bones of the skull, and inside by 3 meninges: hard arachnoid and soft. Each of them has its own device and performs certain tasks.
- The deep soft shell covers both the spinal cord and the brain, while entering all the cracks and grooves of the cerebral hemispheres, and in its thickness there are blood vessels that feed this organ.
- The arachnoid membrane is separated from the first by a subarachnoid space filled with liquor (cerebrospinal fluid), it also contains blood vessels. This sheath consists of connective tissue, from which filiform branched processes (strands) depart, they are woven into a soft sheath and with age their number increases, thereby strengthening the connection. Between them. The villous outgrowths of the arachnoid bulge into the lumen of the sinuses of the dura mater.
- The hard shell or pachymeninx consists of a connective tissue substance and has 2 surfaces: the upper one, saturated with blood vessels, and the inner one, which is smooth and shiny. With this side, the pachymeninx is adjacent to the medulla, and the outer side is adjacent to the cranium. Between the hard and arachnoid there is a narrow space filled with a small amount of liquid.
in the brain healthy person circulates about 20% of the total volume of blood that enters through the posterior cerebral arteries.
The brain can be visually divided into 3 main parts: 2 large hemispheres, trunk and cerebellum.
Gray matter forms the cortex and covers the surface of the cerebral hemispheres, and a small amount of it in the form of nuclei is located in the medulla oblongata.
In all brain regions there are ventricles, in the cavity of which the cerebrospinal fluid, which is formed in them, moves. In this case, the fluid from the 4th ventricle enters the subarachnoid space and washes it.
The development of the brain begins even during the intrauterine presence of the fetus, and it is finally formed by the age of 25.
Main parts of the brain
picture is clickable
What is the brain composed of and study the composition of the brain ordinary person can be from the pictures. The structure of the human brain can be viewed in several ways.
The first divides it into components that make up the brain:
- Final, represented by 2 cerebral hemispheres, united by the corpus callosum;
- intermediate;
- average;
- oblong;
- the posterior borders on the medulla oblongata, the cerebellum and the bridge depart from it.
It is also possible to single out the main composition of the human brain, namely, it includes 3 large structures that begin to develop even during embryonic development:
- diamond-shaped;
- average;
- anterior brain.
In some teaching aids The cerebral cortex is usually divided into sections, so that each of them plays a specific role in the higher nervous system. Accordingly, the following sections of the forebrain are distinguished: frontal, temporal, parietal and occipital zone.
Large hemispheres
First, consider the structure of the cerebral hemispheres.
The end brain of a person controls all vital important processes and is divided by a central sulcus into 2 cerebral hemispheres, covered on the outside with a bark or gray matter, and inside they consist of white matter. Between themselves, in the depths of the central gyrus, they are united by the corpus callosum, which serves as a link connecting and transmitting information between other departments.
The structure of the gray matter is complex and, depending on the site, consists of 3 or 6 layers of cells.
Each lobe is responsible for performing certain functions and coordinates the movement of the limbs on its part, for example, the right part processes non-verbal information and is responsible for spatial orientation, while the left part specializes in mental activity.
In each of the hemispheres, specialists distinguish 4 zones: frontal, occipital, parietal and temporal, they perform certain tasks. In particular, the parietal part of the cerebral cortex is responsible for visual function.
The science that studies the detailed structure of the cerebral cortex is called architectonics.
Medulla
This section is part of the brain stem and serves as a link between the dorsal and the bridge of the terminal section. Since it is a transitional element, it combines the features of the spinal and structural features of the brain. The white matter of this section is represented by nerve fibers, and the gray matter is in the form of nuclei:
- The nucleus of the olive, is a complementary element of the cerebellum, is responsible for balance;
- The reticular formation connects all the sense organs with the medulla oblongata, is partially responsible for the work of some parts of the nervous system;
- The nuclei of the nerves of the skull, these include: glossopharyngeal, vagus, accessory, hypoglossal nerves;
- The nuclei of respiration and circulation, which are connected with the nuclei of the vagus nerve.
This internal structure is due to the functions of the brain stem.
He is responsible for defensive reactions body and regulates vital processes such as heartbeat and blood circulation, so damage to this component leads to instant death.
Pons
The composition of the brain includes the pons, it serves as a link between the cerebral cortex, the cerebellum and the spinal cord. It consists of nerve fibers and gray matter, in addition, the bridge serves as a conductor of the main artery that feeds the brain.
midbrain
This part has a complex structure and consists of a roof, a midbrain part of a tire, a Sylviian aqueduct and legs. In the lower part it borders on the posterior region, namely the pons and the cerebellum, and at the top of it is the diencephalon connected to the terminal.
The roof consists of 4 hills, inside which the nuclei are located, they serve as centers for the perception of information received from the eyes and hearing organs. Thus, this part is included in the zone responsible for receiving information, and refers to the ancient structures that make up the structure of the human brain.
Cerebellum
The cerebellum occupies almost the entire back part and repeats the basic principles of the structure of the human brain, that is, it consists of 2 hemispheres and an unpaired formation connecting them. The surface of the cerebellar lobules is covered with gray matter, and inside they consist of white, in addition, the gray matter in the thickness of the hemispheres forms 2 nuclei. The white matter connects the cerebellum to the brainstem and spinal cord with three pairs of legs.
This brain center is responsible for coordinating and regulating the motor activity of human muscles. It also helps to maintain a certain posture in the surrounding space. Responsible for muscle memory.
Bark
The structure of the cerebral cortex is quite well studied. So, it is a complex layered structure 3-5 mm thick, which covers the white matter of the cerebral hemispheres.
The cortex is formed by neurons with bundles of filiform processes, afferent and efferent nerve fibers, glia (provide the transmission of impulses). It has 6 layers, different in structure:
- grainy;
- molecular;
- external pyramidal;
- internal granular;
- internal pyramidal;
- the last layer consists of spindle-shaped cells.
It occupies about half the volume of the hemispheres, and its area in a healthy person is about 2200 square meters. see. The surface of the bark is dotted with furrows, in the depths of which one third of its entire area lies. The size and shape of the furrows of both hemispheres is strictly individual.
The cortex was formed relatively recently, but is the center of the entire higher nervous system. Experts distinguish several parts in its composition:
- neocortex (new) main part covers more than 95%;
- archicortex (old) - about 2%;
- paleocortex (ancient) - 0.6%;
- intermediate cortex, occupies 1.6% of the total cortex.
It is known that the localization of functions in the cortex depends on the location of the nerve cells that pick up one of the types of signals. Therefore, there are 3 main areas of perception:
- Touch.
- Motor.
- Associative.
The last region occupies more than 70% of the crust, and its central purpose is to coordinate the activity of the first two zones. It is also responsible for receiving and processing data from the sensory zone, and the goal-directed behavior caused by this information.
Between the cerebral cortex and the medulla oblongata is the subcortex or, in other words, the subcortical structures. It consists of visual tubercles, hypothalamus, limbic system and other nerve nodes.
The main functions of the brain regions
The main function of the brain is to process data received from environment, as well as control of the movements of the human body and its mental activity. Each part of the brain is responsible for performing specific tasks.
The medulla oblongata controls the execution protective functions body such as blinking, sneezing, coughing and vomiting. It also controls other reflex vital processes - breathing, secretion of saliva and gastric juice, swallowing.
With the help of the Varoliyev bridge, the coordinated movement of the eyes and facial wrinkles is carried out.
The cerebellum controls the motor and coordination activity of the body.
The midbrain is represented by the stalk and the quadrigemina (two auditory and two visual hillocks). With its help, orientation in space, hearing and clarity of vision is carried out, it is responsible for the muscles of the eyes. Responsible for the reflex turn of the head towards the stimulus.
The diencephalon consists of several parts:
- The thalamus is responsible for the formation of feelings, such as pain or taste. In addition, he manages tactile, auditory, olfactory sensations and rhythms of human life;
- The epithalamus consists of the pineal gland, which controls the daily biological rhythms, dividing the daylight hours into the time of wakefulness and the time of healthy sleep. Has the ability to detect light waves through the bones of the skull, depending on their intensity, produces the appropriate hormones and controls metabolic processes in the human body;
- The hypothalamus is responsible for the work of the heart muscles, the normalization of body temperature and blood pressure. With its help, a signal is given for the release of stress hormones. Responsible for feelings of hunger, thirst, pleasure and sexuality.
The posterior pituitary gland is located in the hypothalamus and is responsible for the production of hormones that affect puberty and the functioning of the human reproductive system.
Each hemisphere is responsible for its own specific tasks. For example, the right cerebral hemisphere accumulates data about the environment and the experience of communicating with it. Controls the movement of the limbs on the right side.
In the left cerebral hemisphere there is a speech center responsible for human speech, it also controls analytical and computational activities, and abstract thinking is formed in its cortex. Similarly, the right side controls the movement of the limbs on its side.
The structure and function of the cerebral cortex directly depend on each other, so the gyrus conditionally divides it into several parts, each of which performs certain operations:
- temporal lobe, controls hearing and charm;
- the occipital part regulates vision;
- in the parietal, touch and taste are formed;
- the frontal parts are responsible for speech, movement and complex thought processes.
The limbic system consists of the olfactory centers and the hippocampus, which is responsible for adapting the body to change and regulating the emotional component of the body. It creates enduring memories by associating sounds and smells with a specific period of time during which sensory upheavals occurred.
In addition, it controls restful sleep, data retention in short-term and long-term memory, intellectual activity, control of the endocrine and autonomic nervous system, and participates in the formation of the reproductive instinct.
How the human brain works
The work of the human brain does not stop even in a dream, it is known that some departments also function in people who are in a coma, as evidenced by their stories.
The main work of this body is carried out with the help of the cerebral hemispheres, each of which is responsible for a certain ability. It is noticed that the hemispheres are not the same in size and function - the right side is responsible for visualization and creative thinking, usually more than the left side, which is responsible for logic and technical thinking.
It is known that men have a larger brain mass than women, but this feature does not affect mental abilities. For example, this figure for Einstein was below average, but his parietal zone, which is responsible for cognition and image creation, was large sizes, which allowed the scientist to develop the theory of relativity.
Some people are endowed with super abilities, this is also the merit of this body. These features are manifested in a high speed of writing or reading, photographic memory and other anomalies.
One way or another, the activity of this organ is of great importance in the conscious control of the human body, and the presence of the cortex distinguishes humans from other mammals.
What, according to scientists, constantly occurs in the human brain
Specialists studying the psychological capabilities of the brain believe that the performance of cognitive and mental functions occurs as a result of biochemical currents, however, this theory is based on currently is questioned, because this organ is a biological object and the principle of mechanical action does not allow to know its nature completely.
The brain is a kind of steering wheel of the whole organism, performing a huge number of tasks every day.
The anatomical and physiological features of the structure of the brain have been the subject of study for many decades. It is known that this organ occupies a special place in the structure of the central nervous system (central nervous system) of a person, and its characteristics are different for each person, therefore it is impossible to find 2 absolutely identically thinking people.
Video
Many guys had to make unexpected surprises to their lovers. One of the unforeseen surprises can be considered a portrait of his beloved girl, made by himself, and the process of working on it filmed on video. But how to draw a girl's head in stages, conveying all the subtleties of the face, emotions, look? Some believe that only professional artists can do such work, but if you show desire and patience, study the basic proportions and rules for building a face, you can make a good drawing yourself. Well, let's try to figure out how to draw a head with a pencil in stages.
So, what do you need to know to draw a person's head in stages? Portrait of a girl or a guy - complex view art, so you need to start it by studying the stages of work. Professional Artists It is advised to first study the following tips:
Main contour and center lines
The initial contour of the face - main stage in the correct image of a portrait of a person. The head drawn in pencil begins with an oval face. No matter how strange it may sound, but the beginning of this oval should be a circle. To do this, in the center of the picture, you need to put a point along which the orientation of the further picture is carried out.
You can use a compass to make a circle of the desired radius from a given point. Then a straight line down is drawn from it, crossing the bend of the circle for the same length as before it. This will be the extreme point of the jaw. Lightly pressing on the pencil, you should make the correct oval: on top - rounded, on the bottom - pointed. Its shape can be different, because the face is round, elongated or bony.
Those who want to learn how to draw a head in stages with a pencil need to learn how to apply centerlines on an oval (make a sketch). They help the correct construction of the face, its proportions. First, a line is drawn horizontally in the center, dividing the pattern in half. Then each of the resulting halves is divided in parallel even in half. In the middle of the oval, a vertical axis is drawn along the face. You get a kind of grid of 8 branches.
Expressive eyes - the basis of the picture
A novice artist should know that the eyes are depicted in the middle of the oval (head). The eyes will be placed on the central horizontal axis. What should be the distance between them and the width? To do this, this axis must be divided into 8 equal intervals. It is important to remember that the distance between the eyes should correspond to one more eye. Therefore, from the central point to the left and right, we retreat one gap at a time, we begin to draw the eyes, each of which will occupy the next two gaps. The width of each eye will correspond to 2/8 of the center line. The main thing is that they are not too close to each other or too far (it is important to choose the middle, you can do without a grid).
With the help of the eyes, the expressiveness of the face is transmitted, so it is important to accurately draw their shape and position them correctly. You should start the image by drawing the lower and upper eyelids. It is necessary to clearly highlight the corners of the eyes. Above upper eyelid you need to depict the palpebral groove in the form of an arc, also repeat from below, only smaller. great attention should be given to the eyeball (iris and pupil). The look will be expressive if the pupils are directed in one direction. Here are some nuances of the image of the eyes:
Draw the nose
Let's try to understand further how to draw a head in stages. After the contours of the eyes, you should move on to the shape of the nose. Where should it be located? The height of the nose should correspond to the size of the central and lower horizontal lines. The width starts from the corners of the eyes. From them, carefully draw lines down to the line, above which we draw three circles. They will help to more accurately depict the nostrils, wings of the nose and the central part. Focusing on this basis, we begin to make an accurate drawing of the nose.
Eyebrow and hair highlighting
Further, the drawing begins to acquire a more detailed image. Having made the bridge of the nose, let's try to move on to neat eyebrows. To do this, the picture can be flipped horizontally. It is important to know that it is better to start the image of the eyebrows from a point closer to the nose. The correct height of the eyebrow above the level of the eye should correspond to one more eye.
After the outlines of the shape of the eyebrows are made, we will apply strokes resembling hairs. Near the nose, they will turn out to be wider and thicker, and towards the end - thinner and sparse.
After drawing the eyebrows, you need to move on to the hair. Here everything will depend on the hairstyle.
The correct outlines of the lips and face
The next element to sketch is the lips or mouth. How to properly position it. Everything is simple. It should be in the center of the lowest part of the grid, under the nose. To determine its horizontal length, draw two lines down from the irises of the eyes, this will be the width of the company. In the marked place we will try to draw neat lips. The bottom one is easier to draw, so it's best to start with it. We simply copy the top one along the bottom one, just divide it in half. Some girls have plump lips, others have thinned ones, you can navigate from the photo.
To complete the sketch, you need to clearly draw the outlines of the face. To do this, you can highlight the cheekbones a little.
Ear position
The shape and position of the ears also need to be given due attention. The height of the ear is approximately equal to the height of the nose. The ear consists of 5 parts: lobe, helix, antihelix, tragus, antitragus. To begin with, we depict the auricle ( general form). Then draw a C-shaped curl. With the help of shadows and light we make the inner part of the ear.
Working on details and shadows
Now we erase the grid lines, we got the initial one. Further work is to decorate and add shadows. The face needs to be more specific. Cheekbones and the shape of the chin play an important role here. It is important not to turn a girl into a man whose chin is stronger.
How to draw a head in stages with a pencil, like real artists? For this we need soft pencil, with which we will apply shadows that give volume to the face. Contrasts and shadows can highlight the desired parts of the portrait, for this you need to determine the darker and lighter places. First, you can simply circle them, then start shading. After that, the hatching can be shaded with a piece of paper in right places. Straight strokes will make the drawing angular and hard.
Finishing touches
The girl's face requires special attention, as it is decorated with hair (hairstyle). It should look natural and suitable for this type of face. Beautiful flowing hair adorn female image. You can also add part of the shoulders and neck to it.
The highlight of each drawing is facial expressions and depiction of emotions. This can be done with eyebrows. One has only to raise or lower them a little - the face will sparkle with new colors. The upturned inner corners of the eyes will help portray sadness, sometimes even crying face. A more embittered person can be depicted by bringing the eyebrows to the bridge of the nose.
Facial expressions can also be drawn by darkening the iris of the eyes and raising the corners of the lips. The darker the pupil, the more expressive the look. From the first time it is difficult to draw a smile on the face, but even a small raising of the corners of the lips makes the girl cute. Facial expressions help to express the character of a person. It is important to remember that you need to constantly train your skills, then facial expressions and emotions of a person will be more accurately obtained.
The brain is the main regulator of the functions of any living organism, one of the elements Until now, medical scientists have been studying the features of the brain and discovering its new incredible possibilities. This is a very complex organ that connects our body with the external environment. The parts of the brain and their functions regulate all life processes. External receptors catch signals and inform any part of the brain about incoming stimuli (light, sound, tactile, and many others). The response is immediate. Let's take a closer look at how our head "processor" works.
General description of the brain
The brain regions and their functions completely control our life processes. Consists of human brain out of 25 billion neurons. This incredible number of cells forms the gray matter. The brain covers several layers:
- soft;
- hard;
- arachnoid (cerebrospinal fluid circulates here).
Liquor is a cerebrospinal fluid, in the brain it plays the role of a shock absorber, a protector from any impact force.
In both men and women, the brain is developed in exactly the same way, although its weight is different. More recently, the debate has subsided that the weight of the brain plays some role in mental development and intellectual abilities. The conclusion is unambiguous - it is not. The weight of the brain is approximately 2% of the total mass of a person. In men, its average weight is 1,370 g, and in women - 1,240 g. The functions of the parts of the human brain are developed in a standard way, vital activity depends on them. Mental capacity depend on the quantitative connections created in the brain. Each brain cell is a neuron that generates and transmits impulses.
The cavities inside the brain are called ventricles. The cranial paired nerves go to different departments.
Functions of the brain regions (table)
Every part of the brain has a job to do. The table below clearly demonstrates this. The brain, like a computer, clearly performs its tasks, receiving commands from the outside world.
The functions of the brain regions, the table reveals schematically and succinctly.
Let's take a closer look at the parts of the brain below.
Structure
The picture shows how the brain works. Despite this, the most significant part is occupied by all parts of the brain and their functions play a huge role in the functioning of the body. There are five main divisions:
- final (of the total mass is 80%);
- posterior (bridge and cerebellum);
- intermediate;
- oblong;
- average.
At the same time, the brain is divided into three main parts: the brain stem, the cerebellum, and the two cerebral hemispheres.
telencephalon
It is impossible to briefly describe the structure of the brain. To understand the parts of the brain and their functions, it is necessary to study their structure closely.
The telencephalon stretches from the frontal to the occipital bone. Two cerebral hemispheres are considered here: left and right. This section is different from others. largest number furrows and convolutions. The development and structure of the brain are closely linked. Experts have identified three types of bark:
- ancient (with olfactory tubercle, anterior perforated substance, semilunar subcallosal and lateral subcallosal gyrus);
- old (with dentate gyrus - fascia and hippocampus);
- new (represents the rest of the cortex).
The hemispheres are separated by a longitudinal groove, in its depths there is a vault and a corpus callosum, which connect the hemispheres. The corpus callosum itself is lined and belongs to the neocortex. The structure of the hemispheres is quite complex and resembles multilevel system. Here, the frontal, temporal, parietal and occipital lobes, subcortex and cortex are distinguished. The large hemispheres perform a huge number of functions. It is worth noting that left hemisphere commands the right side of the body, and the right, on the contrary, the left.
Bark
The surface layer of the brain is the cortex, it has a thickness of 3 mm, covers the hemispheres. The structure consists of vertical nerve cells with processes. The cortex also contains efferent and afferent nerve fibers, as well as neuroglia. The parts of the brain and their functions are discussed in the table, but what is the cortex? Its complex structure has horizontal layering. The building has six layers:
- external pyramidal;
- external granular;
- internal granular;
- molecular;
- internal pyramidal;
- with spindle cells.
Each has a different width, density, shape of neurons. Vertical bundles of nerve fibers give the cortex a vertical striation. The area of the cortex is approximately 2,200 square centimeters, the number of neurons here reaches ten billion.
Parts of the brain and their functions: cortex
The cortex controls several specific bodily functions. Each share is responsible for its own parameters. Let's take a closer look at the functions associated with hotels:
- temporal - controls the sense of smell and hearing;
- parietal - responsible for taste and touch;
- occipital - vision;
- frontal - complex thinking, movement and speech.
Each neuron contacts other neurons, there are up to ten thousand contacts (gray matter). Nerve fibers are white matter. Some part unites the hemispheres of the brain. White matter includes three types of fibers:
- association links connect different cortical areas in one hemisphere;
- commissural connect the hemispheres to each other;
- projection ones communicate with lower formations, have paths of analyzers.
Considering the structure and functions of the brain, it is necessary to emphasize the role of gray and white matter. The hemispheres inside have (gray matter), their main function is the transmission of information. The white matter is located between the cerebral cortex and the basal ganglia. There are four parts here:
- between furrows in convolutions;
- in the outer places of the hemispheres;
- included in the inner capsule;
- located in the corpus callosum.
The white matter located here is formed by nerve fibers and connects the cortex of the convolutions with the underlying sections. form the subcortex of the brain.
The telencephalon - manages all the vital functions of the body, as well as the intellectual abilities of a person.
diencephalon
The brain regions and their functions (table above) include the diencephalon. If you look in more detail, it is worth saying that it consists of ventral and dorsal parts. The hypothalamus belongs to the ventral, and the thalamus, metathalamus, and epithalamus to the dorsal.
The thalamus is a mediator that directs the received irritations to the hemispheres. It is often referred to as the "optic tubercle". It helps the body quickly adapt to changes in external environment. The thalamus is connected to the cerebellum via the limbic system.
The hypothalamus controls autonomic functions. The influence goes through the nervous system, and, of course, the endocrine glands. Regulates the work of the endocrine glands, controls metabolism. The pituitary gland is located directly below it. regulates body temperature, cardiovascular digestive system. The hypothalamus also controls our eating and drinking behavior, regulates wakefulness and sleep.
Rear
The hindbrain includes the pons located in front and the cerebellum, which is located behind. Studying the structure and functions of the parts of the brain, let's take a closer look at the structure of the bridge: the dorsal surface is covered by the cerebellum, the ventral one is represented by a fibrous structure. The fibers are directed transversely in this section. On each side of the bridge, they depart to the cerebellar middle peduncle. In appearance, the bridge resembles a thickened white roller located above the medulla oblongata. The nerve roots exit into the bulbar pontine groove.
The structure of the posterior bridge: on the frontal section, it can be seen that the department of the anterior (large ventral) and posterior (small dorsal) parts consists. Between them, the trapezoid body serves as a boundary, the transverse thick fibers of which are considered to be the auditory pathway. Conductor function is completely dependent on the hindbrain.
Cerebellum (small brain)
The table "Department of the brain, structure, functions" indicates that the cerebellum is responsible for the coordination and movement of the body. This department is located behind the bridge. The cerebellum is often referred to as the "small brain". It occupies the posterior cranial fossa, covers the rhomboid. The mass of the cerebellum ranges from 130 to 160 g. Above are the large hemispheres, which are separated by a transverse fissure. The lower part of the cerebellum is adjacent to the medulla oblongata.
Two hemispheres are distinguished here, the lower, upper surface and the worm. The boundary between them is called a horizontal deep slit. A lot of cracks cut the surface of the cerebellum, between them there are thin convolutions (rollers). Between the grooves there are groups of convolutions, divided into lobules, they represent the lobes of the cerebellum (posterior, flocculent-nodular, anterior).
The cerebellum contains both grey, and gray is located on the periphery, forming a cortex with molecular and pear-shaped neurons, and a granular layer. Under the cortex there is a white substance that penetrates into the gyrus. In the white matter there are blotches of gray (its nuclei). In cross section, this ratio is similar to a tree. Those who know the structure of the human brain, the functions of its departments, will easily answer that the cerebellum is the regulator of the coordination of the movements of our body.
midbrain
The midbrain is located in anterior section bridge and goes to the papillary bodies, as well as to the visual tracts. Here clusters of nuclei are distinguished, which are called tubercles of the quadrigemina. The structure and functions of the brain regions (table) indicate that this department is responsible for latent vision, the orienting reflex, gives orientation to reflexes to visual and sound stimuli, and also maintains muscle tone in the human body.
medulla oblongata: brainstem
The medulla oblongata is a natural extension of the spinal cord. That is why the structure has a lot in common. This becomes especially clear if we examine the white matter in detail. It is represented by short and long nerve fibers. In the form of nuclei, gray matter is represented here. Parts of the brain and their functions (table presented above) indicates that medulla controls our balance, coordination, regulates metabolism, controls breathing and blood circulation. It is also responsible for such important reflexes of our body as sneezing and coughing, vomiting.
The brain stem is divided into the hindbrain and midbrain. The trunk is called the middle, oblong, bridge and diencephalon. Its structure is descending and ascending paths connecting the trunk with the spinal cord and brain. In this part, control over the heartbeat, breathing, articulate speech is carried out.
Neck bones consist of seven cervical vertebrae, which include the upper part of the spine. Large muscles that influence the shape of the neck are the trapezius muscle in the back and the sternomastoideus muscle in the front. They run from the back of the ear down to the inner ends of the clavicles.
Neck able to move in all directions: Tilt your head back and forth, sideways to either shoulder, and rotate it from side to side 180 degrees.
Apart from the sound-conducting structures in the ears, only the jaw moves from the joints of the head. All other bones of the skull are rigidly linked and immovable.
The muscles of the face can be conditionally divided into two types:
The proportions of the human head. Simple construction method
The face is, of course, the most expressive part of the body. Here simple construction method which will help you see which simple forms head consists. Average proportions human head shown in the figure below. The height of the head is about the same as its width when viewed from the side, so in profile it fits into a square. Seen from the front, the width of the head is much less than its height.. 
Start by drawing the head in profile. Draw a circle for the skull and then add two lines on the front of the face to represent the jaw as shown in the image above. 
The most common rookie mistake when depicting the head is that head looks flat. Therefore, as soon as possible, try to draw three-quarter view of the head, trying to display the roundness and solidity of the forms. Use light reference lines to indicate the center line of the face and the position of the eyes. 
The figure shows a rather spineless face, but at this stage the main thing is to understand the basic forms. People's faces differ from the average in many ways, which will be discussed in detail in the following lessons. These drawings represent the first step. If you draw hundreds of these simplified heads, you will come to understand all the subtleties of the relief. human face and be able to fill your drawings with life and character.
The most important thing to understand is that the face is not just a flat surface with details superimposed on it. To draw faces successfully, you must understand three-dimensional shape surfaces - that's why we started with a spineless average face that can belong to both a man and a woman. 
If you look at the hazy newspaper photo of the crowd below, you will see that each face differs from the rest only in the display of light and shadow on it, and not in the shape of the eyes or lips. If you can imagine face as a pattern, in this case you will avoid the common mistake of creating lifeless mechanisms of eyes, noses and mouths, indistinguishable from each other. 
That's why practice drawing the face template with the addition of light and shadow until you fully understand its shape. 
The images above show several basic face and head shapes under different angle. Once again, it is important now that you understood real shape surfaces and not just a plan.
The article used materials from the book Ron Tiner "Figure Drawing without a model".
The human brain is one of the most complex and magnificent organs in the human body. Our brain gives us self-awareness and awareness of our environment by processing a constant stream of sensory data. The neurons of the brain record the memory of every event in our lives. It is an organ that coordinates muscle moments, analyzes data streams from the senses, controls the secretion of glands, remembers past experiences, controls emotions and thoughts, controls the intellect. Every creative thought, feeling, and plan is designed by our brain. The brain is a domed mass of soft nervous tissue protected by a bony case called the skull. It is the command center of the human nervous system. It receives information in the form of electrical impulses and analyzes them and generates the corresponding signal. The human brain is large in size in proportion to the body, compared to the brains of other living beings. It weighs about 1.5 kilograms, consumes 20% of the total oxygen and glucose in the body. The front of the brain should be narrow as well back side should be wide, as shown in the picture.
Step-by-step instructions for beginners: how to draw a human brain
1) Draw the basic shape of the brain as shown in the picture.
2) Make wavy curves along the top side of the brain. Divide the brain so that the petals resemble lines, as shown in the picture. Draw the brain stem from the middle.
3) Draw the folds on the brain. The cerebellum should have distinctive lines as shown.
4) It remains to sign each organ and section of the brain to complete the drawing.
