The cerebral cortex ( cortex cer e bri , pallium ) – gray matter layer (2 – 5 mm) on the surface of the cerebral hemispheres, it is formed by bodies of neurons and glial cells, pa withlaid in layers. Bark – a place of higher analysis and synthesis of all incoming information to the brain, the integration of all forms of complex dressings e Denia and higher mental functions. Currently replaced by exclusive representation of the participation of the neocortex in the formation of complex behaviors, including conditioned reflexes, it’s an idea of it as the highest level of thalamocortical systems operating in conjunction with the thalamus, striopallidarnoy, limbic and other systems ie brain Mami.
Cerebral cortex represented the ancient crust (paleocortex), Art and swarm bark (arhikorteks, arhiokorteks), intermediate or secondary, to a swarm of (mezokorteks) and new cortex (neocortex). An important distinctive feature of the structure of the cortex is the presence of grooves and convolutions. Each hemisphere is divided into five lobes – frontal ( frontal); parietal ; occipital , temporal and insular . It separates the frontal lobe from the parietal lobe tse n tral (rolandova) furrow. The frontal lobe distinguish predtsentral s gyro, upper, middle and lower gyrus. The lateral, or sylvieva, groove separates the temporal lobe from the frontal and parietal. Related n Nye fraction comprises meanders such as postcentral upper and audio w NJ parietal lobule.
The ancient and old crust include a number of large hemispheric structures that phylogenetically emerged before the neocortex. The ancient cortex, or p and leocortex, is the simplest cortex of the big hemispheres, which contains 2 – 3 layers of neurons. Components of ancient crust yavl I are olfactory tubercle and the surrounding crust. Olfactory brain topographically divided into two departments: Department of peripheral (obonyatel s naya share) and central ny department (gyrus). The structure of the peripheral of the first department includes education, lying on the base of the brain – the olfactory bulb; olfactory tract; olfactory triangle; medial and lateral olfactory gyrus; medial and lateral obon Ibody stripes; anterior perforated space or substance; diagonal strip or Broca strip. The structure of the olfactory brain include such formations as the hippocampus and the amygdala.
The main structural feature of the cortex is a display principle of its organization for which the most characteristic proper organization of cells and fibers perpendicular to the surface or steam coming l allel her. Such a similar orientation of many neurons in the cortex provides an opportunity for STI to unite in groups of neurons. The cellular composition in the new bark is very diverse; the size of neurons ranges from 8-9 microns to 150 microns. A person has a new bark, t. e. gray matter takes Prima p but 96 % of the total surface of the cerebral hemispheres (thickness gray matter stake b letsya from 1.5 to 4.5 mm) and is characterized by multi-layered. In the cortex vzro with logo person can distinguish six layers (stratum and NOC), which have their morphological features – neuronal composition orient a tion of neurons, dendrites and axons location.
Different mammals and in different parts of the neocortex of Dr. Foot and the same animal or human, there are certain features of the STI in a thin neural organization, the number and size of neurons during fiber, branching dendrites, the thickness of the layers. Based on such cytoarchitectonic differences in the cerebral cortex, cytoarchitectonic fields and regions are distinguished (for example, Brodmann’s cytoarchitectonic map). In addition to the horizontal organization of layers in n e o-cortex has a clear vertical organization in the form of neuro systems of the new, united in a vertical cell groups all cortical layers. Such a vertically organized group of cells, which is a function of the nominal unit of the cortex was called the vertical column of the cortex. For a cortical neurons Lonka inherent functional thin specialize and tion. Inside the columns, neurons have a partial overlap topography. Due to the presence of recurrent collaterals, the columns interact with each other, for example, by the type of lateral inhibition. The next stage of integration of neurons in the cortex is a union of several ve p tikalnyh microcolumns into larger units – makrokolonku or functional cortical module. Structural basis for the formation of cortical modules are horizontal branching axons of the stellate cells, as well as horizontal communication axon stellate cells ie current and axon collaterals of pyramidal neurons. Diameter function of tional cortical module is several times the diameter vert and Kalnoy column and is 300 – 600 microns. As the complexity of the brain of the howling organization phylogeny appear particularly modular body and tion in different areas of the neocortex. Of great importance in the functioning of Vania cortex modules are processes intracortical inhibition, D and realizability system inhibitory interneurons. Brake and driver s -particle interactions between functional modules cortex underlie the formation of larger organizations – distributed in B with the cortex of the brain. Modules that make up the distribution e lennye systems are interconnected in a parallel and serial v nye eV and neniya, therefore, such system has several inputs and outputs. Command function it is dynamically allocated by the UCH and stkam, which currently comes to the most important information.
Different cortex depending on vyponyaemyh functions Sect e lyayutsya on: a projection (somatosensory, visual and auditory); m on tori (primary – motor, secondary – premotor); associates in nye (prefrontal, frontal, or peredneassotsiativnaya and parietal-temporal-occipital, parietal, or zadneassotsiativnaya) and the limbic cortex (obitofrontalnaya or orbital)
Projection (sensory) areas of the cortex carry out the highest level of sensory analysis. They receive afferent impulses from special and physical relay nuclei of the thalamus and, spatially distributing it on the screen projection, have the topical principle of organization. Along with the complex sensory analysis in the areas of integration occur and the critical e Skye evaluation of information that comes here on specific AFF is, the rental inputs. Sensory afferent impulses originating in the cortex, a plural representation: each of touch zones comprises of a well, the primary projections, secondary and tertiary. The main sensory zones are the visual, auditory and somatic sensory systems of the cortex.
Association areas of the cortex during the phylogenetic development Prio b PETA increasingly important role in the complex forms of behavior in primates and occupy a considerable part of the neocortex. The main associative zones are the parietal and frontal associative regions. Parietal associative region provides reconstitution of complete images pre d Metov or phenomena. There is carried out the integration of afferent sweat on Cove different sensory systems required to implement to adapt and tion behavior. On the neural groupings of the parietal region, there is a convergence of afferent flows of different modality, t. e. from various sensory receptors, which creates optimal opportunities for afferent synthesis that underlies the perception of a holistic object about 6 times the object and its space-time relationships with other objects. Most neurons in the parietal cortex respond to stimuli of two or three sensory modalities. There are nerve cells that are excited only by a complex of multi-sensory stimuli. Large chi with Luo efferent output of the parietal cortex is in the motor cortex, where there is a formation of arbitrary action of a team-based AFF e rental synthesis. The frontal associative areas of the cortex are fully formed only in primates and humans. They are also characterized by the absence of specialized afferent inputs, polysensory x and the nature of neural reactions, the abundance and complexity of connections with areas of the cortex and deep structures of the brain. A ssotsiativnaya frontal cortex Subpart I etsya into two large regions: prefrontal and orbitofrontal cortex (related to the limbic association cortex). The main function pr e frontal cortex consists in forming the plan to perform to m complexes motor action. Most of the information needed for any activity from the prefrontal area receives per e netemennoy association cortex. Once in postparietal sweeps with tyah cortex undergoes a merger sensory information of different types, primarily somatosensory with visual and auditory starts activation of the prefrontal cortex, which is associated with a postparietal b Fins numerous Intracortical and subcortical connections, for example, through the thalamus. Due to this, the prefrontal cortex receives a complete spatial map of the objects in the field of view. Information about the external space is combined with, and Mr. formation of the position of the body and its parts, and prefro n tal cortex contains all the data in the short-term working memory. On this basis, a plan of forthcoming actions is created, t. e. out of the multitude of possible activities, the necessary and in the most rational sequence are selected . First of all, the position of the eyes directed to the desired object is programmed, coordination of the actions of both hands and t. d. Most of the emerging from straight e frontal cortex signal enters the premotor cortex. In humans, the front portions of the frontal region are involved in the implementation of Naib about Leia complex processes associated with the preservation of identity, forms and Niemi social relations. The frontal cortex in humans neposre d -governmental participate in the activities of the second signal system – a voice alarm system.