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Central nervous system alterations
The central nervous system fulfills very diverse functions;He is in charge of receiving, emitting signals and stimuli to the entire body, is responsible for coordinating both conscious and unconscious functions that allow the survival of the human being, is composed of two parts: the brain;"The brain is the nerve mass contained inside the skull. It is wrapped by the meninges, which are three called membranes: Duramadre, Piamadre and Aracnoids. The brain consists of three more bulky parts: brain, cerebellum and spinal bulb, and other smaller ones. Inside there are brain ventricles full of cerebrospinal fluid ”(Tomás, S.F.) and the spinal cord;“The spinal cord is a long and fragile tubular structure that begins at the end of the brain trunk and continues until it almost reaches the end of the spine. It consists of nerves that transport incoming and outgoing messages between the brain and the rest of the organism ”
In this system we find specialized cells (neurons) that transmit information through synaptic contacts of other neurons, it has three types: sensitive neurons;"Neuron that transports afferent information from sensitive receptors to the central nervous system," Interneurona;"The central nervous system that communicates internally and involved between afferent sensory impulses and efferent motor impulses," and motor neurons;“Neurons that transport the efferent information The central nervous system to the muscles and glands. Dra. Herkulano-hozel points out in Nature magazine:
We have found that the average human brain contains 86 billion neurons and not as the brain researchers who were 100 billion cells believed. If 14 billion neurons at first sight seem few … a small difference, then, in comparison, it should be noted that this number of neurons are those found in the brains of a mandrel … in the brain of a gorilla, etc.., Therefore it is a significant difference.
From the scientific point of view, the nervous system and especially the brain still contain many unknowns. The learning we refer to is cognitive, derived from the central nervous system;what is being called in the didactic areas of the life of each individual, where more knowledge is acquired, that is, a simplification at different levels of learning from experiences, emotions, curiosity, our relationship withThe environment that surrounds us, "the learning and education we receive"
There is also neurotransmitters that are similar to the function of neurons but it makes synapse towards dendrites and sometimes towards the cell body of a receiving neuron, having a deficit of some neurotransmitter can produce serious behavior disorders.
Cognitive learning: the SAR defines learning how to acquire knowledge of something through study or experience. On the other hand "cognitive" refers to the "cognition" that defines the ability of the human being to know through perception and brain organs. The concept of cognitive learning defines the processes involved during the information process, ranging from the sensory entry, pass through the cognitive system and reach the response produced.
The central nervous system (SNC) aims to coordinate, integrate and control the body. It also receives stimuli that can reach both from the outside and from the organs of the same organism, processes such information and prepares answers respectively. That said having an alteration in any cortical zone has a damage in its personality according to the affected area (sensitive, motor or associative).
The alterations of the central nervous system that is considered any type of injury or change suffered by the brain, either by a cranial trauma, an ischemia (also known by stroke, stroke-vascular accident, cerebral infarction), brain tumors, hydrocephalies, anoxias,among others, which affects a disorder in cognitive learning. The importance of having a notion of brain alterations is for people who suffer from it know the cause of their disorder, and those who are associated in health science have sufficient knowledge to diagnose and treat effectively and responsibly before a problem of thisnature.
In ancient times 7000 years to.C It was said that the people who suffered from epilepsies, tumors and even migraines, were subjected in a trepanation practice that consisted of performing a drilling in the skull as a surgical character to these calamities that the individual overcome, successively the first surgical papyrus was recorded.of the nervous system by Edwin Smith. In the book “The origin of the species“ published in the nineteenth century by the evolutionary scientist Charles Darwin tells us the evolution of the nervous system that states that the anélidos were the first indication of the central nervous system (CNS). Another scientist whose contributions were relevant was the Spanish Santiago Ramón y Cajal who made a stainthat the nervous system works as a kind of mesh or network.
The objective of this essay determines brain alterations by acquisition or patient that affects cognitive learning, through documentary inquiry, to provide information to people in general.
- Cognitive neuroscience is responsible for analyzing the cognitive deficit present in people with brain injuries and alterations. There are specialized functions and structures, the connections that are developed at the neuronal level can be very different from one subject to another, in the development of the brain you can have critical points where there is a neural pruning: before 1 year and between 12 and 25years (Mora Umaña, 2018). In the 80s, the development of modern neuroimaging techniques arose, which allowed perceiving the live human brain, both at structural and functional level, the first helps to study anatomy and brain structure with different techniques such as: Tac (axial tomographycomputerized), NMR (nuclear magnetic resonance);And the last one studies the physiology and brain function, for this we have the following methods: SPECT (single photon emission tomography), PET (unique photon emission tomography), NMR (functional nuclear magnetic resonance), such development has made viable theStudy of brain activity associated with different complex psychological functions, this has achieved unprecedented advance in our knowledge of the functional organization of the human brain, which has generated new research perspectives, as well as important applications in clinical practice.
- The first brain studies were based on the fact that: "If different functions are located in different spinal roots, perhaps different functions are located in different parts of the brain" and to justify this proposal in 1023 the philosopher Flourens used the experimental ablation method in different animalsTo demonstrate that the coordination of the movement is directly controlled by the cerebellum and that the brain is responsible for the sensation and perception as Galen and Charles Bell had mentioned long ago. Emanuel Swedenbort agreed with Willis that the brain is the premise of understanding, thought, judgment and will, in addition, was the first to suggest the cortical location located in the motor part towards the anterior part.
- In 1909, the Neuroanatomist Korbinian Brodman after thorough and varied brain observations with representations of extensive fan of types of personalities from the brightest to the most unbalanced concludes and describes that the brain has 52 cortical areas due to its cyto -architectural characteristics;“Areas of different regions for its laminar characteristics that are entirely in neocortex (6 cell layers or sheets) being this in a greater proportion of the hemispheres. Each layer comprises more or less defined cells on the basis of different densities, sizes, shapes, afferences and efferences ”. Placing, thus the Broca area in zone 44 and 52 of Brodman and the Wernicke area in zone 39 and 40 of Brodman.
- Brodman’s areas tend to be of great importance because each specific site can be carefully studied and being able to apply in the field of pathology, these are associated respectively by their cytarchitecture, blood flow, metabolism and characteristic functions. It is divided by 47 cortical areas, but other authors expose it as 52 areas due to its subdivisions of the same sector. Next we present the cortex, areas and circumvolutions of the complex map of the cerebral cortex:
- Primary somatosensory cortex, area 1, 2 and 3;
- Motor cortex, area 4;
- Associative Somatosensory Cortex, Area 5;
- Premotor and postmotor cortex, area 6 and 7;
- Secondary motor cortex, area 8 and 10;
- Prefrontal cortex, area 9 and 12;
- Prefrontal dorsolateral cortex, area 9;
- Frontopolar area, sector 10;
- Orbitofrontal area;Sector 11 and 15;
- Orbitofrontal area, sector 12
- ;Homeostacic Circunvolution, Area 13, 14 and 15;
- Peripaleocortical Claustral, Area 16;
- Primary visual cortex, area 17;
- Visual Associative Cortex, Area 18;
- Visual Associative Cortex, Area 19;
- Media Temporary Circunvolution, Area 21;
- Upper temporal circumvolution, area 22;
- Lunulic system, area 23 and 26;
- Posterior ventral area of the cingulo, sector 23;
- Anterior ventral area of the cingulo, 24;
- Subacrallosa area, sector 25;
- EctoSpinal area of the cingulo, sector 26;
- Rinoenfalo, area 27, 28 and 34;
- Piriform cortex, area 27;
- Entorrinal cortex, area 28,
- Retro -Spanish area of the cingulo, sector 29;
- Subsplenial area of the cingulo, sector 30;
- Dorsosterior area of the cingulo, sector 31;
- Cingulo background area, sector 32;
- INDESEUM GRISEUM, Area 33;
- UNCUS, area 34;
- Perirrinal cortex, area 35;
- Parahipocampal cortex, area 36;
- Side Occipitotemporal Circunvolution, Area 37;
- Temporary Polo, Area 38;
- Wernicke area, sector 22 and 42;
- Circunvolution Angula Heteromodal Association, Area 39;
- Supramarginal Circunvolution Heteromodal Association, Area 40;
- Primary auditory cortex, area 41;
- Gustative cortex, area 43;
- Broca area, sector 44 and 45;Operating Circunvolution, Area 44;
- Triangular circumvolution, area 45;
- Dorsolateral prefrontal cortex, area 46;Lower frontal circumvolution, area 47.
French neurologist Paul Broca (1824 – 1880) and the German Karl Wernicke (1848 – 1905) have investigated about how our brain encodes and decodes the language internally, also that neuronal processes perform so that the theories that have been raised are fulfilled. In scientists’ research on the functioning of the areas of Broca and Wernicke are traditional observations that are now considered superimplified or erroneous, but it has still helped new expectations about the neurophysiology of language. This is built in two main center, the first is in the Wernicke area that receives the acoustic information of the auditory cortex and writing of the visual cortex This is where the meaning of the word would be developed, bone the understanding of it, inThis area is connected by a series of unidirectional fibers called arched fascicle with language production also called as the Broca area, where vocalizations would be encoded allowing the expression of language.
Wernicke proposed that two programs that are: motor and sensitive participate in the language, the first one that is called by the Broca area being responsible for the movements of the mouth and speech because it is adjacent to the central groove or fissure ofRolando this primary motor area in charge of the movements of the hands and feet, among others. The second is responsible for the perception of words being auditory or visual.
To detail the language processing, it is indicated that the visual information route is transmitted in the optical nerve (2nd for cranial) these neurons will travel to the visual area that is located in the occipital lobe, once the information is arrived, the information is directed to theAngular circumvolution that is an association area and finally reaches the Wernicke area decoding the signs received by the stimuli of the optical duct. The auditory information route is transmitted through the vestibulococylear nerve (8th for cranial) will travel to the auditory area that is adjacent to the Wernicke area in the temporal lobe, this information then goes directly to the area before mentioned culminating the decoding of this. Finally the transmission of the Wernicke area where the information has arrived decoded and this will go to the Broca area by fibers called arcuatu fascicle that has a large number of axons allowing the information to travel through nerve ducts. If this gets damage in this area, the patient will not be able to respond correctly in speech, this defect has no arrangement.
Although Wernicke and Broca announced the areas that languages perform these are not in force in their entirety but in a way they were right the problem that the individual has in speech is due to brain failures. There is currently language research such as magnetic resonance and mapping through electro transoperative stimulation, but the most accurate model in the complex language processing is called the double flow model that is accepted that different areas could participate for the language process.
In addition, there are other injuries and disorders that lead to a neuronal defectiveness of the brain. The damage to the bark of association of the parietal, temporal and frontal lobes, produces specific cognitive deficits that indicate a lot about the operations and purposes of each of these regions.
Lesions in the bark of the parietal lobe association: attention deficit
In 1941 the British neurologist W.R. Brain mentioned that the lesions of the parietal lobe as the main consequent consisted of varying degrees of attention or perceptual consciousness, this deficit is known as contralateral negligence syndrome, “inability to pay attention to objects or even the body itself in a portionof space ”, affected individuals do not communicate, do not respond or orie. It is important to note that this syndrome is specifically associated with the damage of the right parietal cortex.
Temporary lobe association cortex: recognition deficit
Main functions of the brain is the recognition and identification of stimuli to which attention pays, especially complex stimuli. Damage to any of the temporal lobes can cause problems of recognition, identification and denomination of different categories of objects together (Greek "do not know"). Patients with agnosias associated with contralateral negligence syndrome, deny knowledge of sensitive information in the left visual field, that is, the receiving neurons do not encode the left visual information ignoring the space of this. Prosopagnosia (from the Greek Prosopo, which means "face" or "person"), was studied by neurologists at the end of the 19th century and continues to be an area of intense research. Assuming that there is a deficit in the lower temporal lobe cortex typically on the right side, patients cannot recognize faces and some categorically different recognition regions. The left temporal lobe cortex usually causes problems with the language related to the language (the bark adjacent to the auditory cortex in the left temporal lobe is specifically linked to language).
Injuries in the Frontal Lobe Association cortex: Planning deficit
Subsequent behavioral deficit of frontal lobe damage reflects the role that this part of the brain plays in the maintenance of what is normally considered an individual’s personality, this integrates the complex perceptual information of sensitive and motor cortesand temporary. The cognitive functions that the frontal cortex meets is the selection, planning and execution of appropriate behavior, especially in social contexts.