Lecture 12. The etiology and pathogenesis of the various forms of developmental disorders.
Objective: The relevance of the etiology and pathogenesis of the various forms of developmental disorders.
1. Etiology and pathogenesis
2. Reasons of deviation in development
Etiology (literally-the doctrine of the reason), a term used only in medicine in the sense of the doctrine of the "causes" of disease. Under the general banner Ethyol. factors usually appear and the grounds and the reasons for it, b, and a variety of related conditions conducive to their emergence, and finally a variety of reasons to exercise more or • a b-no. Attempts to differentiation of all these, so different in their theoretical and practical factors znachoniyu although I found, but due to the wrong methodological orientations do not lead to any satisfactory results. So for example. Martius (Martius) came to the conclusion that the sole cause of any disease is a • constitution of the sick, on which Bauer (J. Bauer) quipped that according to this theory is the cause of burn skin. Bauer himself distinguishes between mandatory and optional conditions and causes, and causes the value recognizes only a factor that can not be replaced by any other; He refuses to recognize the cause of pneumonia, colds, as an injury or other factor may appear in some cases instead of cold.
Pathogenesis (pathos - "suffering" + genesis - "emergence") - the doctrine of the mechanisms of disease and pathological processes. Pathogenesis largely depends on the etiologic factors that are triggering mechanism, and in some cases are critical throughout the illness. Examples include endocrine, hereditary diseases, most infectious diseases. Pathogenesis study at both the origin and development and the completion stage of the disease.
By reason of deviation in development, as indicated by the EM Mastyukova understand the impact on the body adverse external or internal factor, which determines the specific lesion or developmental disorders of psychomotor functions. Almost any more or less long-term adverse effects on the developing brain of a child can lead to deviations in psychophysical development. Their effects will be different - depending on the time of the negative effects of its length, the body structure of hereditary and particularly central nervous system (CNS) as well as socio-cultural conditions to those in which the child is brought. All of these factors in combination determine the leading defect that may manifest itself in the form of intelligence failure, speech, vision, hearing, motor skills disorders of emotional and volitional behavior.
The defect (from the Latin defectus -. Defection, decay, lack of) development - a physical or mental defect, causing disruption of the normal development of the child, that does not mean only the presence of negative symptoms. He does not deny some positive trends in the development of abnormal children who depend on external conditions, such as the appropriate training, and are the result of the child's adaptation to the environment (natural compensation). For example, a blind child exacerbated hearing, touch, smell and thermal sensitivity, help him to navigate in space. Deaf child picks up movement, music by vibrating sensations.
Thus, the nature of mental and physical development, different from the norm leads to a significant qualitative features of the formation of the child's personality. In the first place, it is relying on better preserved function that allows you to overcome the conditions of the special education or the most biologically smooth due to failure.
In some cases, there may be several violations, then talk about the complex defect (blind-deaf dumbness). Complicated defect characterized by a combination of two or more violations to the same extent determine the structure of the atypical child development and challenges in implementing educational practices in relation to it. When complex defects can be released leading or major violations and complicating his frustration. Lead and complicating defects may have the character of damage or underdevelopment. Often they are combined.
Feature of a child's brain is that even his small lesion is not partial, local as can occur in adults, and has a negative effect on the whole process of maturation of the central nervous system (53). It defines the uniqueness of the child's development. For example, increasing the size of one of the ventricles of the brain causes an increase in intracranial pressure that causes hyperactivity, hyperexcitability child. This, in turn, leads to the breakdown of perception, attention, memory and thinking.
Defects can be differentiated (from the Latin differentia -. The difference, division, dismemberment) with respect to time occurrence on congenital and acquired. At birth defects adverse effects on the body occurs in utero (prenatal) or during labor and delivery (natal). Acquired defects are the result of pathological factors after birth (postnatal).
The occurrence of abnormalities associated with the effect of various environmental factors and hereditary effects. The former include various infections, intoxication, injuries. Depending on the time of exposure is isolated prenatal pathology - exposure in utero (mother's diseases: measles, rubella, chicken pox, hepatitis, influenza, bruised fruit, hypoxia, incompatibility Rh factor of mother and fetus, fasting mother, alcoholism, drug addiction) natal pathology - lesions at delivery (forceps wrong fetal head, asphyxia, clinical death) and postnatal - adverse effects after birth (infectious disease: encephalitis, meningitis; inflammatory diseases of the brain - as a consequence of the transferred measles, scarlet fever, chicken pox, cranio injuries, somatic diseases, which do not allow the child to learn how ordinary children).
The consequences of intrauterine infections of the nervous system include microcephaly, hydrocephalus, spastic (increased muscle tone), paralysis and paresis, obsessive involuntary movements (hyperkinesia).
The second group (hereditary), transmitted through the chromosomes of parents (now it is 6-7 children per 1,000 live births) include: mental retardation (50%), blurred vision, hearing, speech, locomotor system. Usually this complex defects. The most striking example of chromosomal imbalance is disease - Down's syndrome ( "mongolism") when chromosomal human cells lacking one or has an extra chromosome (21th). In this disease the prevailing intellectual disabilities are imbecility and idiocy. Such people are usually good-natured, affectionate, friendly. The originality of the appearance and the presence of characteristic physical features of children with Down syndrome was the reason for physicians as NB notes Lurie, nothing to talk about the diagnosis and recognition of such patients. They often are stunted; the head they usually have a circular shape; neck flattened, chamfered. Face several flattened. The nose is short, small, with a depressed nasal bridge. Cheeks wide, round, often covered with a blush. The lower jaw protrudes. There is an increased secretion of saliva. Lips thickened. Language wide, large and often protruding from the half-open mouth. In most cases, it is riddled with deep furrows, for which he received the name of the geographical. Eye slit placed obliquely above the inner corner hangs a skin fold - epicanthus. Hands and fingers are short - clumsy. In addition, , hair loss, muscle hypotonia, and "laxity" of the joints, so that these people can, for example, throw a leg over the head. Occurrence: 1 in 600 newborns. The risk of having a child with this disorder is greatest when women aged 35 years and older.
By hereditary disorders also include genetic diseases, when the number and structure of chromosomes remain unchanged. A gene is a microsite of the chromosome that controls the development of a specific hereditary trait. gene stability is high, but not absolute. Under the influence of unfavorable external influences (radiation) gene can mutate and further development program feature on pathological basis. If struck by a single locus (microsite) chromosome, say the monogenic forms of abnormal development, if more - polygenic forms.
The above reasons psychophysical developmental disabilities are organic, because organic cause damage of the cerebral cortex. Defects can be caused by the development and functional reasons: the socio-cultural and psycho-pedagogical neglect, lack of emotional and verbal communication with an adult child, bilingualism in the family, the speech of others. In this case, there will be a deficiency of development.
Each type of abnormal development, according to B.P Puzanov, characterized by systemic manifestations, which are distinguished primary and secondary deviation.
For example, a primary defect may be a lesion of the cerebral cortex of various localization, secondary - violation in the development of mental and physical processes, and tertiary - the deviation in the emotional-volitional sphere, the formation of personal qualities. Secondary and tertiary structure of the deviation depends on the nature of the defect, and driving them is caused. For example, children with impaired hearing will be observed violation of an understanding reverse speech, the slow formation of the active vocabulary and connected speech. Secondary developmental disorders affecting primarily the most intensively developing in the preschool mental functions: speech, fine motor skills, spatial representation, arbitrary regulation of movements.
Undiagnosed developmental abnormalities such as mild sensory impairment, especially delayed the pace of mental development of the child, and may also promote the formation of secondary emotional and personality disorders in children (42). Such a child who is in regular school are often observed a situation of failure, low self-esteem, low aspirations.
1. Give a definition of the defect.
2. Give examples of complex defects.
3. What is the difference between a primary defect of the secondary?
4. What groups of disorders or pathologies emit, depending on time of influence of adverse factors?
5. What kind of pathological factors may act on the child's body in the prenatal period?
6. List the reasons natal pathology.
7. What are the adverse factors may cause malformations of the body of the child after birth?
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