It consists of the thalamus, epithalamus, metathalamus and hypothalamus. ascending fibers from the hypothalamus from the raphe nuclei of the locus coeruleus of the reticular formation of the brain stem and partially from the spinothalamic tracts as part of the medial lemniscus. Hypothalamus General structure and location of the hypothalamus.

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Introduction

Thalamus (visual thalamus)

Hypothalamus

Conclusion

References

Introduction

For a modern psychologist, the anatomy of the central nervous system is the basic layer of psychological knowledge. Without an understanding of the physiological functioning of the brain, it is impossible to qualitatively study mental processes and phenomena, as well as understand their essence.

Speaking about the thalamus and hypothalamus, we should first talk aboutdiencephalon(diencephalon ). The diencephalon is located above the midbrain, under the corpus callosum. It consists of the thalamus, epithalamus, metathalamus and hypothalamus. At the base of the brain, its anterior border runs along the anterior surface of the optic chiasm, the anterior edge of the posterior perforated substance and optic tracts, and posteriorly along the edge of the cerebral peduncles. On the dorsal surface, the anterior border is the terminal strip separating the diencephalon from the telencephalon, and the posterior border is the groove separating the diencephalon from the superior colliculi of the midbrain. In a sagittal section, the diencephalon is visible under the corpus callosum and fornix.

The cavity of the diencephalon is III ventricle, which communicates through the right and left interventricular foramina with the lateral ventricles located inside the cerebral hemispheres and through the cerebral aqueduct with the cavity IV cerebral ventricle. In the upper wall III In the ventricle there is a choroid plexus, which, along with plexuses in other ventricles of the brain, participates in the formation of cerebrospinal fluid.

The thalamic brain is divided into paired formations:

thalamus ( thalamus);

metathalamus (zathalamic region);

epithalamus (suprathalamic region);

subthalamus (subthalamic region).

The metathalamus (zathalamic region) is formed by pairedmedial and lateral geniculate bodieslocated behind each thalamus. The geniculate bodies contain nuclei in which impulses going to the cortical sections of the visual and auditory analyzers are switched.

The medial geniculate body is located behind the thalamic cushion; together with the lower colliculi of the midbrain roof plate, it is the subcortical center of the auditory analyzer.

The lateral geniculate body is located inferior to the thalamic cushion. Together with the superior colliculus, it forms the subcortical center of the visual analyzer.

Epithalamus (suprathalamic region) includespineal body (epiphysis), leashes and triangles of leashes. The triangles of the leashes contain nuclei related to the olfactory analyzer. The leashes extend from the triangles of the leashes, go caudally, are connected by a commissure and pass into the pineal gland. The latter is, as it were, suspended on them and is located between the upper tubercles of the quadrigeminal. The pineal gland is an endocrine gland. Its functions have not been fully established; it is assumed that it regulates the onset of puberty.

Thalamus (visual thalamus)

General structure and location of the thalamus.

Thalamus, or thalamus, is a paired ovoid formation with a volume of about 3.3 cm 3 , consisting mainly of gray matter (clusters of numerous nuclei). Thalami are formed due to thickening of the lateral walls of the diencephalon. In front, the pointed part of the thalamus formsanterior tubercle,in which the intermediate centers of sensory (afferent) pathways running from the brain stem to the cerebral cortex are located. Posterior, expanded and rounded part of the thalamus - pillow - contains the subcortical visual center.

Figure 1 . Diencephalon in sagittal section.

The thickness of the gray matter of the thalamus is divided vertically Y -shaped layer (plate) of white matter into three parts - anterior, medial and lateral.

Medial surface of the thalamusclearly visible on the sagittal (sagittal - sagittal (lat. " sagitta" - arrow), dividing into symmetrical right and left halves) in a section of the brain (Fig. 1). The medial (i.e., located closer to the middle) surface of the right and left thalamus, facing each other, form the lateral walls III cerebral ventricle (diencephalon cavity) in the middle they are connected to each otherinterthalamic fusion.

Anterior (inferior) surface of the thalamusfused with the hypothalamus, through it, from the caudal side (i.e., located closer to the lower part of the body), pathways from the cerebral peduncles enter the diencephalon.

Lateral (i.e. side) surface thalamus borders oninternal capsule -a layer of white matter of the cerebral hemispheres, consisting of projection fibers connecting the cerebral cortex with the underlying brain structures.

Each of these parts of the thalamus contains several groupsthalamic nuclei. In total, the thalamus contains from 40 to 150 specialized nuclei.

Functional significance of the thalamic nuclei.

According to topography, the thalamic nuclei are divided into 8 main groups:

1. anterior group;

2. mediodorsal group;

3. group of midline nuclei;

4. dorsolateral group;

5. ventrolateral group;

6. ventral posteromedial group;

7. posterior group (nuclei of the thalamic cushion);

8. intralaminar group.

The nuclei of the thalamus are divided into sensory ( specific and nonspecific),motor and associative. Let us consider the main groups of thalamic nuclei necessary to understand its functional role in the transmission of sensory information to the cerebral cortex.

Located in the anterior part of the thalamus front group thalamic nuclei (Fig.2). The largest of them areanteroventral core and anteromedialcore. They receive afferent fibers from the mammillary bodies, the olfactory center of the diencephalon. Efferent fibers (descending, i.e. carrying impulses from the brain) from the anterior nuclei are directed to the cingulate gyrus of the cerebral cortex.

The anterior group of thalamic nuclei and associated structures are an important component of the limbic system of the brain, which controls psycho-emotional behavior.

Rice. 2 . Topography of thalamic nuclei

In the medial part of the thalamus there aremediodorsal nucleus And group of midline nuclei.

Mediodorsal nucleushas bilateral connections with the olfactory cortex of the frontal lobe and the cingulate gyrus of the cerebral hemispheres, the amygdala and the anteromedial nucleus of the thalamus. Functionally, it is also closely connected with the limbic system and has bilateral connections with the parietal, temporal and insular cortex of the brain.

The mediodorsal nucleus is involved in the implementation of higher mental processes. Its destruction leads to a decrease in anxiety, anxiety, tension, aggressiveness, and the elimination of obsessive thoughts.

Midline nucleiare numerous and occupy the most medial position in the thalamus. They receive afferent (i.e., ascending) fibers from the hypothalamus, from the raphe nuclei, the locus coeruleus of the reticular formation of the brain stem, and partially from the spinothalamic tracts as part of the medial lemniscus. Efferent fibers from the midline nuclei are sent to the hippocampus, amygdala and cingulate gyrus of the cerebral hemispheres, which are part of the limbic system. Connections with the cerebral cortex are bilateral.

The midline nuclei play an important role in the processes of awakening and activation of the cerebral cortex, as well as in supporting memory processes.

In the lateral (i.e. lateral) part of the thalamus there aredorsolateral, ventrolateral, ventral posteromedial And posterior group of nuclei.

Nuclei of the dorsolateral grouprelatively little studied. They are known to be involved in the pain perception system.

Nuclei of the ventrolateral groupanatomically and functionally differ from each other.Posterior nuclei of the ventrolateral groupoften considered as one ventrolateral nucleus of the thalamus. This group receives fibers from the ascending tract of general sensitivity as part of the medial lemniscus. Fibers of taste sensitivity and fibers from the vestibular nuclei also come here. Efferent fibers starting from the nuclei of the ventrolateral group are sent to the cortex of the parietal lobe of the cerebral hemispheres, where they carry somatosensory information from the whole body.

TO posterior group nuclei(nucleus of the thalamic cushion) there are afferent fibers from the superior colliculi and fibers in the optic tracts. Efferent fibers are widely distributed in the cortex of the frontal, parietal, occipital, temporal and limbic lobes of the cerebral hemispheres.

The nuclear centers of the thalamic cushion are involved in the complex analysis of various sensory stimuli. They play a significant role in the perceptual (related to perception) and cognitive (cognitive, thinking) activity of the brain, as well as in memory processes - storing and reproducing information.

Intralaminar group of nucleithe thalamus lies in the thickness of the vertical Y -shaped layer of white matter. The intralaminar nuclei are interconnected with the basal ganglia, the dentate nucleus of the cerebellum and the cerebral cortex.

These nuclei play an important role in the activation system of the brain. Damage to the intralaminar nuclei in both thalami leads to a sharp decrease in motor activity, as well as apathy and destruction of the motivational structure of the personality.

The cerebral cortex, thanks to bilateral connections with the nuclei of the thalamus, is capable of exerting a regulatory effect on their functional activity.

Thus, the main functions of the thalamus are:

processing of sensory information from receptors and subcortical switching centers with its subsequent transfer to the cortex;

participation in the regulation of movements;

ensuring communication and integration of different parts of the brain.

Hypothalamus

General structure and location of the hypothalamus.

Hypothalamus ) represents the ventral section (i.e., abdominal) of the diencephalon. It consists of a complex of formations located under III ventricle The hypothalamus is limited anteriorlyvisual cross (chiasm), laterally - the anterior part of the subthalamus, the internal capsule and the optic tracts extending from the chiasm. Posteriorly, the hypothalamus continues into the tegmentum of the midbrain. The hypothalamus includesmastoid bodies, gray tubercle and optic chiasm. Mastoid bodieslocated on the sides of the midline anterior to the posterior perforated substance. These are formations of irregular spherical shape, white. Anterior to the gray tubercle is locatedoptic chiasm. In it, a transition occurs to the opposite side of part of the optic nerve fibers coming from the medial half of the retina. After the decussation, the optic tracts are formed.

Gray tubercle located anterior to the mastoid bodies, between the optic tracts. The gray tubercle is a hollow protrusion of the lower wall III ventricle, formed by a thin plate of gray matter. The apex of the gray mound is elongated into a narrow hollow funnel , at the end of which is pituitary gland [ 4; 18].

Pituitary gland: structure and functioning

Pituitary (hypophysis) - an endocrine gland, it is located in a special depression at the base of the skull, the “sella turcica” and is connected to the base of the brain with the help of a pedicle. The pituitary gland contains the anterior lobe (adenohypophysis - glandular pituitary gland) and the posterior lobe (neurohypophysis).

Posterior lobe, or neurohypophysis, consists of neuroglial cells and is a continuation of the hypothalamic infundibulum. Larger share - adenohypophysis, built of glandular cells. Due to the close interaction of the hypothalamus with the pituitary gland, a single system functions in the diencephalonhypothalamic-pituitary system,controlling the work of all endocrine glands, and with their help, the vegetative functions of the body (Fig. 3).

Figure 3. The pituitary gland and its influence on other endocrine glands

There are 32 pairs of nuclei in the gray matter of the hypothalamus. Interaction with the pituitary gland is carried out through neurohormones secreted by the nuclei of the hypothalamus -releasing hormones. Through the system of blood vessels they enter the anterior lobe of the pituitary gland (adenohypophysis), where they contribute to the release of tropic hormones that stimulate the synthesis of specific hormones in other endocrine glands.

In the anterior lobe of the pituitary gland tropic ones are produced hormones (thyroid-stimulating hormone - thyrotropin, adrenocorticotropic hormone - corticotropin and gonadotropic hormones - gonadotropins) and effector hormones (growth hormones - somatotropin and prolactin).

Hormones of the anterior pituitary gland

Tropic:

Thyroid-stimulating hormone (thyrotropin)stimulates thyroid function. If the pituitary gland is removed or destroyed in animals, atrophy of the thyroid gland occurs, and the administration of thyrotropin restores its functions.

Adrenocorticotropic hormone (corticotropin)stimulates the function of the zona fasciculata of the adrenal cortex, in which hormones are formedglucocorticoids.The effect of the hormone on the zona glomerulosa and reticularis is less pronounced. Removal of the pituitary gland in animals leads to atrophy of the adrenal cortex. Atrophic processes affect all zones of the adrenal cortex, but the most profound changes occur in the cells of the reticular and fascicular zones. The extra-adrenal effect of corticotropin is expressed in stimulation of lipolysis processes, increased pigmentation, and anabolic effects.

Gonadotropic hormones (gonadotropins).Follicle stimulating hormone ( follitropin) stimulates the growth of the vesicular follicle in the ovary. The effect of follitropin on the formation of female sex hormones (estrogens) is small. This hormone is present in both women and men. In men, under the influence of follitropin, the formation of germ cells (spermatozoa) occurs. Luteinizing hormone ( lutropin) necessary for the growth of the vesicular follicle of the ovary in the stages preceding ovulation, and for ovulation itself (rupture of the membrane of a mature follicle and the release of an egg from it), the formation of the corpus luteum at the site of the burst follicle. Lutropin stimulates the formation of female sex hormones - estrogens. However, in order for this hormone to exert its effect on the ovary, a preliminary long-term action of follitropin is necessary. Lutropin stimulates the production progesterone yellow body. Lutropin is available in both women and men. In men, it promotes the formation of male sex hormones - androgens.

Effector:

Growth hormone (somatotropin)stimulates body growth by enhancing protein formation. Under the influence of the growth of epiphyseal cartilages in the long bones of the upper and lower extremities, bone growth occurs in length. Growth hormone increases insulin secretion through somatomedins, formed in the liver.

Prolactin stimulates the formation of milk in the alveoli of the mammary glands. Prolactin exerts its effect on the mammary glands after the preliminary action of the female sex hormones progesterone and estrogens on them. The act of sucking stimulates the formation and release of prolactin. Prolactin also has a luteotropic effect (promotes the long-term functioning of the corpus luteum and the formation of the hormone progesterone).

Processes in the posterior lobe of the pituitary gland

The posterior lobe of the pituitary gland does not produce hormones. Inactive hormones that are synthesized in the paraventricular and supraoptic nuclei of the hypothalamus enter here.

The hormones are predominantly produced in the neurons of the paraventricular nucleus oxytocin, and in the neurons of the supraoptic nucleus -vasopressin (antidiuretic hormone).These hormones accumulate in the cells of the posterior pituitary gland, where they are converted into active hormones.

Vasopressin (antidiuretic hormone)plays an important role in the processes of urine formation and, to a lesser extent, in the regulation of blood vessel tone. Vasopressin, or antidiuretic hormone - ADH (diuresis - urine output) - stimulates the reabsorption (resorption) of water in the renal tubules.

Oxytocin (ocytonin)increases uterine contraction. Its contraction increases sharply if it was previously under the influence of the female sex hormones estrogen. During pregnancy, oxytocin does not affect the uterus, since under the influence of the corpus luteum hormone progesterone, it becomes insensitive to oxytocin. Mechanical irritation of the cervix causes the release of oxytocin reflexively. Oxytocin also has the ability to stimulate milk production. The act of sucking reflexively promotes the release of oxytocin from the neurohypophysis and the secretion of milk. In a state of stress in the body, the pituitary gland releases additional amounts of ACTH, which stimulates the release of adaptive hormones by the adrenal cortex.

Functional significance of the hypothalamic nuclei

IN anterolateral part hypothalamus is distinguished anterior and middlegroups of hypothalamic nuclei (Fig. 4).

Figure 4. Topography of the hypothalamic nuclei

The anterior group includes suprachiasmatic nuclei, preoptic nucleus,and the largest -supraoptic And paraventricular kernels.

In the nuclei of the anterior group are localized:

center of the parasympathetic division (PSNS) of the autonomic nervous system.

Stimulation of the anterior hypothalamus leads to parasympathetic reactions: constriction of the pupil, a decrease in heart rate, dilation of the lumen of blood vessels, a drop in blood pressure, increased peristalsis (i.e., wave-like contraction of the walls of hollow tubular organs, promoting the movement of their contents to the intestinal outlets);

heat transfer center. Destruction of the anterior section is accompanied by an irreversible increase in body temperature;

thirst center;

neurosecretory cells that produce vasopressin (supraoptic core) and oxytocin ( paraventricular nucleus). In neurons paraventricular And supraopticnuclei, a neurosecretion is formed, which moves along their axons to the posterior part of the pituitary gland (neurohypophysis), where it is released in the form of neurohormones -vasopressin and oxytocinentering the blood.

Damage to the anterior nuclei of the hypothalamus leads to the cessation of the release of vasopressin, resulting in the development ofdiabetes insipidus. Oxytocin has a stimulating effect on the smooth muscles of internal organs, such as the uterus. In general, the water-salt balance of the body depends on these hormones.

In the preoptic The nucleus produces one of the releasing hormones - luliberin, which stimulates the production of luteinizing hormone in the adenohypophysis, which controls the activity of the gonads.

Suprachiasmaticnuclei take an active part in the regulation of cyclical changes in the body's activity - circadian, or daily, biorhythms (for example, in the alternation of sleep and wakefulness).

To the middle group hypothalamic nuclei includedorsomedial And ventromedial nucleus, nucleus of the gray tuberosity and the core of the funnel.

In the nuclei of the middle group are localized:

center of hunger and satiety. Destructionventromedialhypothalamic nucleus leads to excess food consumption (hyperphagia) and obesity, and damagekernels of gray mound- loss of appetite and sudden weight loss (cachexia);

sexual behavior center;

center of aggression;

the center of pleasure, which plays an important role in the processes of formation of motivations and psycho-emotional forms of behavior;

neurosecretory cells that produce releasing hormones (liberins and statins), regulating the production of pituitary hormones: somatostatin, somatoliberin, luliberin, folliberin, prolactoliberin, thyreoliberin, etc. Through the hypothalamic-pituitary system they influence growth processes, the rate of physical development and puberty , the formation of secondary sexual characteristics, the functions of the reproductive system, as well as metabolism.

The middle group of nuclei controls water, fat and carbohydrate metabolism, affects blood sugar levels, the ionic balance of the body, the permeability of blood vessels and cell membranes.

Posterior part of the hypothalamus located between the gray tubercle and the posterior perforated substance and consists of the right and leftmastoid bodies.

In the posterior part of the hypothalamus, the largest nuclei are: medial and lateral nucleus, posterior hypothalamic nucleus.

In the nuclei of the posterior group are localized:

center that coordinates the activity of the sympathetic division (SNS) of the autonomic nervous system (posterior hypothalamic nucleus). Stimulation of this nucleus leads to sympathetic reactions: pupil dilation, increased heart rate and blood pressure, increased respiration and decreased tonic contractions of the intestines;

heat production center (posterior hypothalamic nucleus). Destruction of the posterior hypothalamus causes lethargy, drowsiness and decreased body temperature;

subcortical centers of the olfactory analyzer. Medial and lateral nucleusin each mastoid body they are the subcortical centers of the olfactory analyzer, and are also part of the limbic system;

neurosecretory cells that produce releasing hormones that regulate the production of pituitary hormones.

Features of the blood supply to the hypothalamus

The nuclei of the hypothalamus receive abundant blood supply. The capillary network of the hypothalamus is several times more branched than in other parts of the central nervous system. One of the features of the capillaries of the hypothalamus is their high permeability, caused by the thinning of the walls of the capillaries and their fenestration ("fenestration" - the presence of spaces - "windows" - between adjacent endothelial cells of the capillaries (from the Latin. " fenestra " - window). As a result, the blood-brain barrier (BBB) ​​is weakly expressed in the hypothalamus, and hypothalamic neurons are able to perceive changes in the composition of the cerebrospinal fluid and blood (temperature, ion content, presence and amount of hormones, etc.).

Functional significance of the hypothalamus

The hypothalamus is the central link connecting the nervous and humoral mechanisms of regulation of the autonomic functions of the body. The control function of the hypothalamus is determined by the ability of its cells to secrete and axonally transport regulatory substances, which are transferred to other structures of the brain, cerebrospinal fluid, blood or pituitary gland, changing the functional activity of target organs.

There are 4 neuroendocrine systems in the hypothalamus:

Hypothalamic-extrahypothalamic systemrepresented by neurosecretory cells of the hypothalamus, the axons of which extend into the thalamus, structures of the limbic system, and medulla oblongata. These cells secrete endogenous opioids, somatostatin, etc.

Hypothalamic-adenopituitary systemconnects the nuclei of the posterior hypothalamus with the anterior lobe of the pituitary gland. Releasing hormones (liberins and statins) are transported along this pathway. Through them, the hypothalamus regulates the secretion of tropic hormones of the adenohypophysis, which determine the secretory activity of the endocrine glands (thyroid, reproductive, etc.).

Hypothalamic-metapituitary systemconnects the neurosecretory cells of the hypothalamus with the pituitary gland. The axons of these cells transport melanostatin and melanoliberin, which regulate the synthesis of melanin, the pigment that determines the color of the skin, hair, iris and other body tissues.

Hypothalamic-neurohypophyseal systemconnects the nuclei of the anterior hypothalamus with the posterior (glandular) lobe of the pituitary gland. These axons transport vasopressin and oxytocin, which accumulate in the posterior lobe of the pituitary gland and are released into the bloodstream as needed.

Conclusion

Thus, the dorsal part of the diencephalon is phylogenetically youngerthalamic brain,being the highest subcortical sensory center in which almost all afferent pathways carrying sensory information from the body organs and sensory organs to the cerebral hemispheres are switched. The tasks of the hypothalamus also include the management of psycho-emotional behavior and participation in the implementation of higher mental and psychological processes, in particular memory.

Ventral section - the hypothalamus is phylogenetically older formation. The hypothalamic-pituitary system controls the humoral regulation of water-salt balance, metabolism and energy, the functioning of the immune system, thermoregulation, reproductive function, etc. Performing a regulatory role for this system, the hypothalamus is the highest center that controls the autonomic (autonomic) nervous system.

References

1. Human Anatomy / Ed. M.R. Sapina. - M.: Medicine, 1993.
2. Bloom F., Leiserson A., Hofstadter L. Brain, mind, behavior. - M.: Mir, 1988.
3. Histology / Ed. V.G. Eliseeva. - M.: Medicine, 1983.
4. Prives M.G., Lysenkov N.K., Bushkovich V.I. Human anatomy. - M.: Medicine, 1985.
5. Sinelnikov R.D., Sinelnikov Y.R. Atlas of human anatomy. - M.: Medicine, 1994.
6. Tishevskaya I.A. Anatomy of the central nervous system: Textbook. - Chelyabinsk: SUSU Publishing House, 2000.

1. Structure of the telencephalon.

Surfaces of the cerebral hemispheres.

Cerebral cortex.

Basal ganglia and white matter terminal

2. Structure of the diencephalon.

Hypothalamus.

III ventricle.

3. The main pathways of the brain.

Ascending afferent pathways.

Descending efferent pathways.

1. Structure of the telencephalon.

Finite brain(telencephalon) consists of two cerebral hemispheres, separated from each other by a longitudinal fissure. In the depths of the gap there is a connection connecting them corpus callosum. In addition to the corpus callosum, the hemispheres also connect front, back spikes And vault commissure. Each hemisphere has three poles: frontal, occipital and temporal. Three edges (superior, inferior and medial) divide the hemispheres into three surfaces: superolateral, medial and inferior. Each hemisphere is divided into lobes. Central sulcus(Rolandova) separates the frontal lobe from the parietal lobe, lateral groove(Sylvian) temporal from the frontal and parietal, the parieto-occipital fissure separates the parietal and occipital lobes. The insula is located deep in the lateral sulcus. Smaller grooves divide the lobes into convolutions.

Superolateral surface of the cerebral hemisphere. Frontal lobe, located in the anterior section of each hemisphere of the cerebrum, is limited below by the lateral (Sylvian) fissure, and behind by the deep central groove (Rolandic), located in the frontal plane. Anterior to the central sulcus, almost parallel to it, is located precentral sulcus. From the precentral sulcus forward, almost parallel to each other, they are directed top And inferior frontal sulcus, which divide the superolateral surface of the frontal lobe from the gyrus. Between the central sulcus posteriorly and the precentral sulcus anteriorly there is precentral gyrus. Lying above the superior frontal sulcus superior frontal gyrus occupies the upper part of the frontal lobe.

Between the superior and inferior frontal sulci passes middle frontal gyrus. Located inferior to the inferior frontal sulcus inferior frontal gyrus, into which they protrude from behind ascending And anterior branch of the lateral sulcus, dividing the lower part of the frontal lobe into small convolutions. Tegmental part (frontal operculum), located between the ascending branch and the lower part of the lateral sulcus, covers the insular lobe, which lies deep in the sulcus. Orbital part lies inferiorly from the anterior branch, continuing to the inferior surface of the frontal lobe. At this point, the lateral groove widens, turning into lateral fossa cerebrum .

Parietal lobe, located posterior to the central sulcus, separated from the occipital parieto-occipital sulcus, which is located on the medial surface of the hemisphere, protruding deeply into its upper edge. The parieto-occipital groove passes to the lateral surface, where the border between the parietal and occipital lobes is a conventional line - the continuation of this groove downwards. The inferior border of the parietal lobe is the posterior branch of the lateral sulcus, separating it from the temporal lobe. Postcentral sulcus runs behind the central sulcus, almost parallel to it.

Between the central and postcentral sulci is located postcentral gyrus, which at the top passes to the medial surface of the cerebral hemisphere, where it connects with the precentral gyrus of the frontal lobe, forming with it precentral lobule. On the superior lateral surface of the hemisphere below, the postcentral gyrus also passes into the precentral gyrus, covering the central sulcus from below. It extends posteriorly from the postcentral sulcus intraparietal sulcus, parallel to the upper edge of the hemisphere. Above the intraparietal sulcus there is a group of small convolutions called superior parietal lobule; located below inferior parietal lobule.

The smallest occipital lobe located behind parieto-occipital sulcus and its conditional continuation on the superolateral surface of the hemisphere. The occipital lobe is divided into several convolutions by grooves, of which the most constant is transverse occipital sulcus .

Temporal lobe, occupying the inferolateral parts of the hemisphere, is separated from the frontal and parietal lobes by the lateral sulcus. The insular lobe is covered by the edge of the temporal lobe. On the lateral surface of the temporal lobe, almost parallel to the lateral sulcus, runs top And inferior temporal gyri. On the upper surface of the superior temporal gyrus, several weakly defined transverse gyri are visible ( Heschl's convolutions). Between the superior and inferior temporal grooves are located middle temporal gyrus. Below the inferior temporal sulcus is inferior temporal gyrus .

Insula (islet) located in the depths of the lateral sulcus, covered by a tegmentum formed by parts of the frontal, parietal and temporal lobes. Deep circular groove of the insula separates the insula from the surrounding parts of the brain. The inferoanterior part of the insula is devoid of grooves and has a slight thickening - threshold of the island. On the surface of the islet there is long And short convolutions.

Medial surface of the cerebral hemisphere. All of its lobes, except the insular lobe, take part in the formation of the medial surface of the cerebral hemisphere. Sulcus of the corpus callosum goes around it from above, separating the corpus callosum from lumbar gyrus, goes down and forward and continues in hippocampal sulcus .

Passes over the cingulate gyrus cingulate groove, which begins anteriorly and inferiorly from the beak of the corpus callosum. As it rises, the groove turns back and runs parallel to the groove of the corpus callosum. At the level of its ridge, its marginal part extends upward from the cingulate sulcus, and the sulcus itself continues into the subparietal sulcus. The marginal part of the cingulate groove posteriorly limits pericentral lobule, and in front - precuneus, which belongs to the parietal lobe. Inferiorly and posteriorly through the isthmus, the cingulate gyrus passes into parahippocampal gyrus which ends in front crochet and bounded from above hippocampal sulcus . Cingulate gyrus, isthmus And parahippocampal gyrus united under the name vaulted gyrus. Located deep in the hippocampal sulcus dentate gyrus. At the level of the splenium of the corpus callosum, it branches upward from the cingulate sulcus marginal part of the cingulate groove .

Inferior surface of the cerebral hemisphere has the most difficult terrain. In front is the surface of the frontal lobe, behind it is the temporal pole and the lower surface of the temporal and occipital lobes, between which there are no clear boundaries. Between longitudinal slot hemispheres and olfactory sulcus frontal lobe is located gyrus rectus. Lateral to the olfactory sulcus lie orbital gyri . Lingual gyrus the occipital lobe on the lateral side is limited by the occipitotemporal (collateral) groove. This groove passes to the inferior surface of the temporal lobe, dividing parahippocampal And medial occipitotemporal gyrus. Anterior to the occipitotemporal sulcus is nasal groove, limiting the anterior end of the parahippocampal gyrus - hook. Occipitotemporal sulcus divides medial And lateral occipitotemporal gyrus.

Cerebral cortex , cortex cerebri, is the most highly differentiated part of the nervous system.

The cerebral cortex consists of a huge number of cells, which, according to their morphological characteristics, can be divided into six layers:

1. outer zonal, or molecular layer, lamina zonalis ;

2. outer granular layer, lamina granularis externa ;

3. pyramidal layer, lamina pyramidalis ;

4. inner granular layer, lamina granularis interna ;

5. ganglion layer, lamina ganglionaris ;

6. polymorphic layer, lamina multiformis .

The structure of each of these layers of the cortex in different parts of the brain has its own characteristics, expressed in a change in the number of layers, in different numbers, sizes, topography and structure of the nerve cells that form it.

Based on a subtle study of various parts of the cerebral cortex, a large number of fields have now been described in it (see Fig.), each of which is characterized by the individual characteristics of its architectonics, which made it possible to create a map of the fields of the cerebral cortex (cytoarchitectonics), as well as to establish the features distribution of cortical fibers (myeloarchitecture).

Cortical sections Each analyzer in the cerebral cortex has certain areas where their nuclei are localized, and, in addition, separate groups of nerve cells located outside these areas. The nuclei of the motor analyzer are localized in the paracentral gyrus, precentral gyrus, posterior part of the middle and inferior frontal gyri.

In the upper section In the precentral gyrus and pericentral lobule, the cortical sections of the motor analyzers of the muscles of the lower limb are localized; below are areas related to the muscles of the pelvis, abdominal wall, trunk, upper limbs, neck and, finally, in the lowest section - the head.

In the posterior region middle frontal gyrus The cortical section of the motor analyzer for combined head and eye rotation is localized. There is also a motor analyzer of written speech, which is related to voluntary movements associated with writing letters, numbers and other characters.

Posterior part of the inferior frontal gyrus is the location of the motor speech analyzer.

Cortical section of the olfactory analyzer(and taste) is in the hook; visual - occupies the edges of the fissure of the bird's spur, auditory - in the middle part of the superior temporal gyrus, and as far as posterior, in the posterior part of the superior temporal gyrus - the auditory analyzer of speech signals (control of one's speech and perception of someone else's).

Second higher education in psychology in MBA format

item:Anatomy and evolution of the human nervous system.
Manual "Anatomy of the central nervous system"

1.1. History of the anatomy of the central nervous system
1.2. Research methods in anatomy
1.3. Anatomical terminology

Human anatomy is a science that studies the structure of the human body and the patterns of development of this structure.
Modern anatomy, being part of morphology, not only studies the structure, but also tries to explain the principles and patterns of the formation of certain structures. The anatomy of the central nervous system (CNS) is part of human anatomy. Knowledge of the anatomy of the central nervous system is necessary to understand the connection of psychological processes with certain morphological structures, both normally and in pathology.

1.1. History of the anatomy of the central nervous system
Already in primitive times, there was knowledge about the location of the vital organs of humans and animals, as evidenced by rock paintings. IN Ancient world , especially in Egypt, in connection with the mummification of corpses, some organs were described, but their functions were not always represented correctly.

Scientists had a great influence on the development of medicine and anatomy Ancient Greece . An outstanding representative of Greek medicine and anatomy was Hippocrates (c. 460-377 BC). He considered four “juices” to be the basis of the structure of the body: blood (sanguis), mucus (phlegma), bile (chole) and black bile (telaina chole). In his opinion, the types of human temperament depend on the predominance of one of these juices: sanguine, phlegmatic, choleric and melancholic. This is how the “humoral” (liquid) theory of the structure of the body arose. A similar classification, but, of course, with a different semantic content, has survived to this day.

IN Ancient Rome the most prominent representatives of medicine were Celsus and Galen. Aulus Cornelius Celsus (1st century BC) is the author of the eight-volume treatise “On Medicine,” in which he brought together the knowledge he knew about anatomy and practical medicine of ancient times. A great contribution to the development of anatomy was made by the Roman physician Galen (c. 130-200 AD), who was the first to introduce the method of animal vivisection into science and wrote the classic treatise “On the Parts of the Human Body,” in which he first gave an anatomical and physiological description of the whole body. Galen considered the human body to consist of dense and living parts, and based his scientific conclusions on observations of sick people and on the results of autopsies of animal corpses. He was also the founder of experimental medicine, conducting various experiments on animals. However, the anatomical concepts of this scientist were not without shortcomings. For example, Galen conducted most of his scientific research on pigs, whose body, although close to the human body, still has a number of significant differences from it. In particular, Galen attached great importance to the “wonderful network” (rete mirabile) he discovered - the vascular plexus at the base of the brain, since he believed that it was there that the “animal spirit” was formed, controlling movements and sensations. This hypothesis existed for almost 17 centuries, until anatomists proved that pigs and bulls have a similar network, but are absent in humans.

In the era Middle Ages all science in Europe, including anatomy, was subordinated to the Christian religion. Doctors of that time usually referred to the scientists of antiquity, whose authority was supported by the church. At this time, no significant discoveries were made in anatomy. The dissection of corpses, autopsies, and the production of skeletons and anatomical preparations were prohibited. The Muslim East played a positive role in the continuity of ancient and European science. In particular, in the Middle Ages, the books of Ibn Sipa (980-1037), known in Europe as Avicenna, the author of the “Canon of Medicine,” containing important anatomical information, were popular among doctors.

Anatomists of the era Renaissance obtained permission to conduct autopsies. Thanks to this, anatomical theaters were created to conduct public dissections. The founder of this titanic work was Leonardo da Vinci, and the founder of anatomy as an independent science was Andrei Vesalius (1514-1564). Andrei Vesalius studied medicine at the Sorbonne University and very soon realized the insufficiency of the then existing anatomical knowledge for the practical work of a doctor. The situation was complicated by the church's ban on dissection of corpses - the only source of study of the human body at that time. Vesalius, despite the real danger from the Inquisition, systematically studied the human structure and created the first truly scientific atlas of the human body. To do this, he had to secretly dig up the freshly buried corpses of executed criminals and conduct his research on them. At the same time, he exposed and eliminated numerous errors of Galen, which laid the foundation for the analytical period in anatomy, during which many discoveries of a descriptive nature were made. In his writings, Vesalius focused on a systematic description of all human organs, as a result of which he was able to discover and describe many new anatomical facts (Fig. 1.1).

Rice. 1.1. Drawing of a dissected brain from the atlas of Andrei Vesalius (1543):

For his activities, Andrei Vesalius was persecuted by the church, was sent to repentance in Palestine, was shipwrecked and died on the island of Zante in 1564.

After the work of A. Vesalius, anatomy began to develop at a faster pace, in addition, the church no longer so harshly persecuted the dissection of corpses by doctors and anatomists. As a result, the study of anatomy has become an integral part of the training of doctors in all European universities (Fig. 1.2).

Rice. 1.2. Rembrandt Harmens van Rijn. Anatomy lesson of Dr. Tulp (late 17th century):

Attempts to connect anatomical structures with mental activity gave rise to the science of phrenology at the end of the 18th century. Its founder, the Austrian anatomist Franz Gahl, tried to prove the existence of strictly defined connections between the structural features of the skull and the mental characteristics of people. However, after some time, objective studies showed the unfoundedness of phrenological statements (Fig. 1.3).

Rice. 1.3. Drawing from an atlas on phrenology depicting “mounds of secrecy, greed and gluttony” on a man’s head (1790):

The following discoveries in the field of the anatomy of the central nervous system were associated with the improvement of microscopic techniques. First, August von Waller proposed his method of Wallerian degeneration, which makes it possible to trace the paths of nerve fibers in the human body, and then the discovery of new methods of staining nerve structures by E. Golgi and S. Ramon y Cajal made it possible to find out that in addition to neurons in the nervous system there is also a huge number of auxiliary cells - neuroglia.

Remembering the history of anatomical research of the central nervous system, it should be noted that such an outstanding psychologist as Sigmund Freud began his career in medicine as a neurologist - that is, a researcher of the anatomy of the nervous system.

In Russia, the development of anatomy was closely connected with the concept of nervism, which proclaimed the primary importance of the nervous system in regulating physiological functions. In the middle of the 19th century, the Kiev anatomist V. Betz (1834-1894) discovered giant pyramidal cells (Betz cells) in the V layer of the cerebral cortex and revealed differences in the cellular composition of different parts of the cerebral cortex. Thus, he laid the foundation for the doctrine of the cytoarchitectonics of the cerebral cortex.

A major contribution to the anatomy of the brain and spinal cord was made by the outstanding neuropathologist and psychiatrist V. M. Bekhterev (1857-1927), who expanded the doctrine of the localization of functions in the cerebral cortex, deepened the reflex theory and created an anatomical and physiological basis for diagnosing and understanding the manifestations of nervous diseases . In addition, V. M. Bekhterev discovered a number of brain centers and conductors.

Currently, the focus of anatomical studies of the nervous system has moved from the macroworld to the microworld. Nowadays, the most significant discoveries are being made in the field of microscopy not only of individual cells and their organelles, but also at the level of individual biomacromolecules.

1.2. Research methods in anatomy
All anatomical methods can be divided into macroscopic , which study the entire organism, organ systems, individual organs or parts thereof, and on microscopic , the object of which are tissues and cells of the human body and cellular organelles. In the latter case, anatomical methods merge with the methods of such sciences as histology (the science of tissues) and cytology (the science of cells) (Fig. 1.4).

Rice. 1.4. Main groups of methods for studying the morphology of the central nervous system :

In turn, macroscopic and microscopic studies consist of a set of various methodological techniques that make it possible to study various aspects of morphological formations in the nervous system as a whole, in individual areas of nervous tissue, or even in an individual neuron. Accordingly, we can distinguish a set of macroscopic (Fig. 1.5) and microscopic (Fig. 1.6) methods for studying the morphology of the central nervous system

Rice. 1.5. Macroscopic methods for studying the nervous system :

Rice. 1.6. Microscopic methods for studying the nervous system :

Since the task of anatomical research (from the point of view of psychology) is to identify connections between anatomical structures and mental processes, several methods from the arsenal of physiology can be connected to the methods of studying the morphology (structure) of the central nervous system (Fig. 1.7).

Rice. 1.7. General methods for physiology and anatomy of the central nervous system :

1.3. Anatomical terminology
To have a correct understanding of the structures of the brain and spinal cord, it is necessary to know some elements of anatomical nomenclature.

The human body is presented in three planes, horizontal, sagittal and frontal, respectively.
Horizontal the plane runs, as its name suggests, parallel to the horizon, sagittal divides the human body into two symmetrical halves (right and left), frontal the plane divides the body into anterior and posterior parts.

There are two axes in the horizontal plane. If the object is closer to the back, then it is said to be located dorsally, if closer to the stomach - ventrally. If an object is located closer to the midline, to the plane of symmetry of a person, then it is said to be located medially, if further - then laterally.

In the frontal plane, two axes are also distinguished: medio-lateral and rostro-caudal. If an object is located closer to the lower part of the body (in animals - to the back, or tail), then it is said to be caudal, and if it is located to the top (closer to the head), then it is located rostral.

There are also two axes in the human sagittal plane; rostro-caudal and dorso-ventral. Thus, the relative position of any anatomical objects can be characterized by their relative position in three planes and axes.

Nerve endings are located throughout the human body. They have a vital function and are an integral part of the entire system. The structure of the human nervous system is a complex branched structure that runs through the entire body.

The physiology of the nervous system is a complex composite structure.

The neuron is considered the basic structural and functional unit of the nervous system. Its processes form fibers that are excited when exposed and transmit impulses. The impulses reach the centers where they are analyzed. Having analyzed the received signal, the brain transmits the necessary reaction to the stimulus to the appropriate organs or parts of the body. The human nervous system is briefly described by the following functions:

• providing reflexes;
• regulation of internal organs;
• ensuring the interaction of the body with the external environment, by adapting the body to changing external conditions and stimuli;
• interaction of all organs.

The importance of the nervous system lies in ensuring the vital functions of all parts of the body, as well as the interaction of a person with the outside world. The structure and functions of the nervous system are studied by neurology.

Structure of the central nervous system

The anatomy of the central nervous system (CNS) is a collection of neuronal cells and neural processes of the spinal cord and brain. A neuron is a unit of the nervous system.

The function of the central nervous system is to ensure reflex activity and process impulses coming from the PNS.

The anatomy of the central nervous system, the main unit of which is the brain, is a complex structure of branched fibers.

The higher nerve centers are concentrated in the cerebral hemispheres. This is a person’s consciousness, his personality, his intellectual abilities and speech. The main function of the cerebellum is to ensure coordination of movements. The brain stem is inextricably linked with the hemispheres and cerebellum. This section contains the main nodes of the motor and sensory pathways, which ensures such vital functions of the body as regulating blood circulation and ensuring respiration. The spinal cord is the distribution structure of the central nervous system; it provides branching of the fibers that form the PNS.

The spinal ganglion is the site of concentration of sensory cells. With the help of the spinal ganglion, the activity of the autonomic department of the peripheral nervous system is carried out. Ganglia or nerve ganglia in the human nervous system are classified as the PNS; they perform the function of analyzers. Ganglia do not belong to the human central nervous system.

Features of the structure of the PNS

Thanks to the PNS, the activity of the entire human body is regulated. The PNS consists of cranial and spinal neurons and fibers that form ganglia.

The human peripheral nervous system has a very complex structure and functions, so any slightest damage, for example, damage to blood vessels in the legs, can cause serious disruptions to its functioning. Thanks to the PNS, all parts of the body are controlled and the vital functions of all organs are ensured. The importance of this nervous system for the body cannot be overestimated.

The PNS is divided into two divisions - the somatic and autonomic PNS systems.

The somatic nervous system performs double work - collecting information from the sensory organs, and further transmitting this data to the central nervous system, as well as ensuring the motor activity of the body by transmitting impulses from the central nervous system to the muscles. Thus, it is the somatic nervous system that is the instrument of human interaction with the outside world, as it processes signals received from the organs of vision, hearing and taste buds.

The autonomic nervous system ensures the functions of all organs. It controls the heartbeat, blood supply, and breathing. It contains only motor nerves that regulate muscle contraction.

To ensure the heartbeat and blood supply, the efforts of the person himself are not required - this is controlled by the autonomic part of the PNS. The principles of the structure and function of the PNS are studied in neurology.

Departments of the PNS

The PNS also consists of the afferent nervous system and the efferent division.

The afferent region is a collection of sensory fibers that process information from receptors and transmit it to the brain. The work of this department begins when the receptor is irritated due to any impact.

The efferent system differs in that it processes impulses transmitted from the brain to effectors, that is, muscles and glands.

One of the important parts of the autonomic division of the PNS is the enteric nervous system. The enteric nervous system is formed from fibers located in the gastrointestinal tract and urinary tract. The enteric nervous system controls the motility of the small and large intestine. This section also regulates the secretions released in the gastrointestinal tract and provides local blood supply.

The importance of the nervous system is to ensure the functioning of internal organs, intellectual function, motor skills, sensitivity and reflex activity. The child’s central nervous system develops not only during the prenatal period, but also throughout the first year of life. Ontogenesis of the nervous system begins from the first week after conception.

The basis for brain development is formed already in the third week after conception. The main functional nodes are identified by the third month of pregnancy. By this time, the hemispheres, trunk and spinal cord have already been formed. By the sixth month, the higher parts of the brain are already better developed than the spinal part.

By the time a baby is born, the brain is the most developed. The size of the brain in a newborn is approximately an eighth of the child’s weight and ranges from 400 g.

The activity of the central nervous system and PNS is greatly reduced in the first few days after birth. This may include an abundance of new irritating factors for the baby. This is how the plasticity of the nervous system manifests itself, that is, the ability of this structure to be rebuilt. As a rule, the increase in excitability occurs gradually, starting from the first seven days of life. The plasticity of the nervous system deteriorates with age.

Types of CNS

In the centers located in the cerebral cortex, two processes simultaneously interact - inhibition and excitation. The rate at which these states change determines the types of nervous system. While one part of the central nervous system is excited, another is slowed down. This determines the features of intellectual activity, such as attention, memory, concentration.

Types of the nervous system describe the differences between the speed of inhibition and excitation of the central nervous system in different people.

People may differ in character and temperament, depending on the characteristics of the processes in the central nervous system. Its features include the speed of switching neurons from the process of inhibition to the process of excitation, and vice versa.

The types of nervous system are divided into four types.

• The weak type, or melancholic, is considered the most predisposed to the occurrence of neurological and psycho-emotional disorders. It is characterized by slow processes of excitation and inhibition. The strong and unbalanced type is choleric. This type is distinguished by the predominance of excitation processes over inhibition processes.
• Strong and agile - this is a type of sanguine person. All processes occurring in the cerebral cortex are strong and active. A strong but inert, or phlegmatic type, is characterized by a low speed of switching nervous processes.

The types of the nervous system are interconnected with temperaments, but these concepts should be distinguished, because temperament characterizes a set of psycho-emotional qualities, and the type of the central nervous system describes the physiological characteristics of the processes occurring in the central nervous system.

CNS protection

The anatomy of the nervous system is very complex. The central nervous system and PNS suffer due to the effects of stress, overexertion and lack of nutrition. For the normal functioning of the central nervous system, vitamins, amino acids and minerals are necessary. Amino acids take part in brain function and are building materials for neurons. Having figured out why vitamins and amino acids are needed and why, it becomes clear how important it is to provide the body with the necessary amount of these substances. Glutamic acid, glycine and tyrosine are especially important for humans. The regimen for taking vitamin-mineral complexes for the prevention of diseases of the central nervous system and PNS is selected individually by the attending physician.

Damage to bundles of nerve fibers, congenital pathologies and abnormalities of brain development, as well as the action of infections and viruses - all this leads to disruption of the central nervous system and PNS and the development of various pathological conditions. Such pathologies can cause a number of very dangerous diseases - immobility, paresis, muscle atrophy, encephalitis and much more.

Malignant neoplasms in the brain or spinal cord lead to a number of neurological disorders. If an oncological disease of the central nervous system is suspected, an analysis is prescribed - histology of the affected parts, that is, an examination of the composition of the tissue. A neuron, as part of a cell, can also mutate. Such mutations can be identified by histology. Histological analysis is carried out according to the doctor’s indications and consists of collecting the affected tissue and its further study. For benign formations, histology is also performed.

The human body contains many nerve endings, damage to which can cause a number of problems. Damage often leads to impaired mobility of a body part. For example, an injury to the hand can lead to pain in the fingers and impaired movement. Osteochondrosis of the spine can cause pain in the foot due to the fact that an irritated or compressed nerve sends pain impulses to receptors. If the foot hurts, people often look for the cause in a long walk or injury, but the pain syndrome can be triggered by damage to the spine.

If you suspect damage to the PNS, as well as any related problems, you should be examined by a specialist.

Gray and white matter of the brain. White matter of the hemispheres. Gray matter of the hemisphere. Frontal lobe. Parietal lobe. Temporal lobe. Occipital lobe. Island.

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ANATOMY OF THE CENTRAL NERVOUS SYSTEM

ABSTRACT

Topic: "Gray and white matter of the brain"

WHITE MATTER HEMISPHERES

The entire space between the gray matter of the cerebral cortex and the basal ganglia is occupied by white matter. The white matter of the hemispheres is formed by nerve fibers connecting the cortex of one gyrus with the cortex of other gyri of its and the opposite hemispheres, as well as with underlying formations. Topographics in the white matter distinguish four parts, vaguely delimited from each other:

white matter in the gyri between the sulci;

area of ​​white matter in the outer parts of the hemisphere - semi-oval center ( centrum semiovale);

radiant crown ( corona radiata), formed by radiating fibers entering the internal capsule ( capsule interna) and those leaving it;

central substance of the corpus callosum ( corpus callosum), internal capsule and long associative fibers.

White matter nerve fibers are divided into associative, commissural and projection.

Association fibers connect different parts of the cortex of the same hemisphere. They are divided into short and long. Short fibers connect neighboring convolutions in the form of arcuate bundles. Long association fibers connect areas of the cortex that are more distant from each other.

Commissural fibers, which are part of the cerebral commissures, or commissures, connect not only symmetrical points, but also the cortex belonging to different lobes of the opposite hemispheres.

Most of the commissural fibers are part of the corpus callosum, which connects the parts of both hemispheres belonging to neencephalon. Two brain adhesions Commissura anterior And commissura fornicis, much smaller in size belong to the olfactory brain rhinencephalon and connect: Commissura anterior- olfactory lobes and both parahippocampal gyri, commissura fornicis- hippocampi.

Projection fibers connect the cerebral cortex with the underlying formations, and through them with the periphery. These fibers are divided into:

centripetal - ascending, corticopetal, afferent. They conduct excitation towards the cortex;

centrifugal (descending, corticofugal, efferent).

Projection fibers in the white matter of the hemisphere closer to the cortex form the corona radiata, and then the main part of them converges into the internal capsule, which is a layer of white matter between the lenticular nucleus ( nucleus lentiformis) on one side, and the caudate nucleus ( nucleus caudatus) and thalamus ( thalamus) - on the other. On a frontal section of the brain, the internal capsule looks like an oblique white stripe that continues into the cerebral peduncle. In the internal capsule the anterior leg is distinguished ( crus anterius), - between the caudate nucleus and the anterior half of the inner surface of the lentiform nucleus, the posterior peduncle ( crus posterius), - between the thalamus and the posterior half of the lentiform nucleus and genu ( genu), lying at the inflection point between both parts of the internal capsule. Projection fibers can be divided according to their length into the following three systems, starting with the longest:

Tractus corticospinalis (pyramidalis) conducts motor volitional impulses to the muscles of the trunk and limbs.

Tractus corticonuclearis- pathways to the motor nuclei of the cranial nerves. All motor fibers are collected in a small space in the internal capsule (the knee and the anterior two-thirds of its posterior leg). And if they are damaged in this place, unilateral paralysis of the opposite side of the body is observed.

Tractus corticopontini- paths from the cerebral cortex to the pontine nuclei. Using these pathways, the cerebral cortex has an inhibitory and regulatory effect on the activity of the cerebellum.

Fibrae thalamocorticalis et corticothalamici- fibers from the thalamus to the cortex and back from the cortex to the thalamus.

GRAY MATTER OF THE HEMISPHERE

Surface of the hemisphere, cloak ( pallium), formed by a uniform layer of gray matter 1.3 - 4.5 mm thick, containing nerve cells. The surface of the cloak has a very complex pattern, consisting of grooves alternating in different directions and ridges between them, called convolutions, gyri. The size and shape of the grooves are subject to significant individual fluctuations, as a result of which not only the brains of different people, but even the hemispheres of the same individual are not quite similar in the pattern of the grooves.

Deep, permanent grooves are used to divide each hemisphere into large areas called lobes. lobi; the latter, in turn, are divided into lobules and convolutions. There are five lobes of the hemisphere: frontal ( lobus frontalis), parietal ( lobus parietalis), temporal ( lobus temporalis), occipital ( lobus occipitalis) and a lobule hidden at the bottom of the lateral sulcus, the so-called islet ( insula).

The superolateral surface of the hemisphere is delimited into lobes by three grooves: the lateral, central and upper end of the parieto-occipital groove. Lateral sulcus ( sulcus cerebri lateralis) begins on the basal surface of the hemisphere from the lateral fossa and then passes to the superolateral surface. Central sulcus ( sulcus centralis) begins at the upper edge of the hemisphere and goes forward and down. The part of the hemisphere located in front of the central sulcus belongs to the frontal lobe. The part of the brain surface lying posterior to the central sulcus constitutes the parietal lobe. The posterior border of the parietal lobe is the end of the parieto-occipital sulcus ( sulcus parietooccipitalis), located on the medial surface of the hemisphere.

Each lobe consists of a number of convolutions, called in some places lobules, which are limited by grooves on the surface of the brain.

Frontal lobe

In the posterior part of the outer surface of this lobe there is sulcus precentralis almost parallel to the direction sulcus centralis. Two furrows run from it in the longitudinal direction: sulcus frontalis superior et sulcus frontalis inferior. Due to this, the frontal lobe is divided into four convolutions. vertical gyrus, gyrus precentralis, located between the central and precentral sulci. The horizontal gyri of the frontal lobe are: superior frontal ( gyrus frontalis superior), middle frontal ( gyrus frontalis medius) and inferior frontal ( gyrus frontalis inferior) shares.

Parietal lobe

It is located approximately parallel to the central groove sulcus postcentralis, usually merging with sulcus intraparietalis, which goes in the horizontal direction. Depending on the location of these grooves, the parietal lobe is divided into three gyri. vertical gyrus, gyrus postcentralis, goes behind the central sulcus in the same direction as the precentral gyrus. Above the interparietal sulcus is the superior parietal gyrus, or lobule ( lobulus parietalis superior), below - lobulus parietalis inferior.

Temporal lobe

The lateral surface of this lobe has three longitudinal gyri, delimited from each other sulcus temporalis superio r and sulcus temporalis inferior. stretches between the superior and inferior temporal grooves gyrus temporalis medius. Below it passes gyrus temporalis inferior.

Occipital lobe

The grooves on the lateral surface of this lobe are variable and inconsistent. Of these, the transverse one is distinguished sulcus occipitalis transversus, usually connecting to the end of the interparietal sulcus.

Island

This lobe has the shape of a triangle. The surface of the insula is covered with short convolutions.

The lower surface of the hemisphere in that part that lies anterior to the lateral fossa belongs to the frontal lobe.

Here, parallel to the medial edge of the hemisphere, runs sulcus olfactorius. On the posterior portion of the basal surface of the hemisphere two grooves are visible: sulcus occipitotemporalis, passing in the direction from the occipital pole to the temporal and limiting gyrus occipitotemporalis lateralis, and running parallel to it sulcus collateralis. Between them is located gyrus occipitotemporalis medialis. There are two gyri located medially from the collateral sulcus: between the posterior part of this sulcus and sulcus calcarinus lies gyrus lingualis; between the anterior section of this groove and the deep sulcus hippocampi lies gyrus parahippocampalis. This gyrus, adjacent to the brain stem, is already located on the medial surface of the hemisphere.

On the medial surface of the hemisphere there is a groove of the corpus callosum ( sulcus corpori callosi), running directly above the corpus callosum and continuing with its posterior end into the deep sulcus hippocampi, which is directed forward and downward. Parallel to and above this groove runs along the medial surface of the hemisphere sulcus cinguli. Paracentral lobule ( lobulus paracentralis) is called a small area above the lingual sulcus. Posterior to the paracentral lobule there is a quadrangular surface (the so-called precuneus, precuneus). It belongs to the parietal lobe. Behind the precuneus lies a separate area of ​​the cortex belonging to the occipital lobe - the wedge ( cuneus). Between the lingular sulcus and the sulcus of the corpus callosum stretches the cingulate gyrus ( gyrus cinguli), which, through the isthmus ( isthmus) continues into the parahippocampal gyrus, ending in the uncus ( uncus). Gyrus cinguli, isthmus And gyrus parahippocampali s together form the vaulted gyrus ( gyrus fornicatus), which describes an almost complete circle, open only at the bottom and front. The vaulted gyrus is not related to any of the lobes of the cloak. It belongs to the limbic region. The limbic region is part of the neocortex of the cerebral hemispheres, occupying the cingulate and parahippocampal gyri; part of the limbic system. Pushing the edge sulcus hippocampi, you can see a narrow jagged gray stripe, representing a rudimentary gyrus gyrus dentatus.

L I T E R A T U R A

Big medical encyclopedia. vol. 6, M., 1977

2. Great medical encyclopedia. vol. 11, M., 1979

3. M.G. Prives, N.K. Lysenkov, V.I. Bushkovich. Human anatomy. M., 1985

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