| 单词 | starvation | ||||||
| 释义 | starvationstar·va·tionS0713900 (stär-vā′shən)starvation(stɑːˈveɪʃən)star•va•tion(stɑrˈveɪ ʃən)n.
starvationstarve(staːv) verbstarvationstarvation,condition in which deprivation of food has forced the body to feed on itself. Causes are famine, fasting, malnutrition, or abnormalities of the mucosal lining of the digestive system. Famines are often compounded by political strifes that restrict the distribution of aid and imports, as has been demonstrated in Ethiopia, Somalia, Iraq after the Persian Gulf War, and the conflict between the Serbs and Croats in former Yugoslavia. Fasting, usually conducted as a religious discipline or political protest, results in dizziness, weakness, and loss of bone mass; these lead to malnutrition. First to be lost are fat deposits and large quantities of water. The liver, spleen, and muscle tissue then suffer the greatest loss of weight. The heart and brain show little loss proportionately. The starving person becomes weak and lethargic. Body temperature, pulse rate, blood pressure, and basal metabolism continue to fall as starvation progresses, and death eventually ensues.Starvationthe state of an organism that is completely deprived of food, has an insufficient food intake, or suffers from disturbances in its assimilation of food. Starvation as a physiological phenomenon is found in mammals during winter and summer hibernation and during cold torpor in amphibians, insects, fish, and reptiles. In these cases starvation is accompanied by the inhibition of the central nervous system and a sharp drop in the metabolic rate, which permits life to be maintained for a long time with insignificant expenditures of energy. Starvation during this period is connected with biologically produced specific reactions of the organism in its adaptation to the environment. Pathological starvation in man may arise as a result of deprivation or insufficiency of food, the impairment of digestion and assimilation of food, and especially with diseases of the gastrointestinal tract. Starvation is considered complete if only water enters the organism; incomplete, if an insufficient amount of food is entering the organism in relation to the general expenditure of energy; and absolute, when neither water nor food enter the organism. Partial or qualitative starvation may arise when there is an insufficient intake of individual nutrients (proteins, mineral substances, vitamins, and the like). Starvation began to be scientifically studied in the 19th century. It was established that in complete starvation the life of the organism is supported for a certain amount of time by the supply of nutrient material (especially fat) and products that are released as a result of the gradual atrophy of the tissues of the organism itself. It is thought that by the moment of death, about 40–50 percent of the initial amount of protein is destroyed. The general production of energy in the course of starvation gradually diminishes. The duration of life in starvation depends on body weight (the greater the weight, the greater the reserve of energy resources), age (children are more susceptible to starvation, while the middle-aged are more resistant), sex (women have greater endurance), expenditure of energy (with less expenditure— lying down—the duration of life is greater), and on individual peculiarities of the organism. The maximum length of time of starvation for a man is considered to be 65–70 days (in absolute starvation, a few days). Complete starvation is much more easily endured than absolute starvation, both as far as the painfulness of subjective sensations is concerned and the degree of impairment of metabolism. In the development of complete starvation, three stages are distinguished. The first state is that of initial adaptation of the organism (two to four days). During this period, the feeling of hunger is felt more keenly. The appetite increases sharply, as does the motor function of the stomach (up to and including the occurrence of spasms). Metabolism decreases somewhat, and use of the reserves of energetically valuable substances from depots (glycogen from the liver, fat from subcutaneous adipose cellular tissue) occurs. The proteins and energy resources of the organism are used up relatively evenly. Body weight during the first days decreases approximately by up to 1 kg per day. (Thereafter, the daily decrease in body weight becomes smaller.) The second stage is the stage of the organism’s adaptation to life under conditions of starvation (the longest stage). The feeling of hunger weakens, and the appetite disappears; the tongue becomes covered with a white coating (furred), and the mouth and skin begin to give off an odor of acetone. Thirst diminishes, and the pulse becomes slower. The motor function of the stomach decreases. The digestive juices assume the nature of a spontaneous secretion; the sight of food does not cause an intensification of secretion. The juices are rich in proteins, which then split up into amino acids in the intestine. Reverse absorption of amino acids provides a plastic material for subsequent synthesis of necessary protein substances. Urination is regular, but somewhat diminished. There is some accumulation of water in the organism. In the beginning, apparently owing to acidosis, increased irritability, headaches, poor sleep, and later, a decrease in excitability, sluggishness, apathy, and drowsiness are all observed. Mental activity is completely preserved, while muscular activity gradually weakens. With starvation, vital functions progressively decrease in intensity. Toward the beginning of the second stage of starvation the oxidation of carbohydrates sharply decreases, and the basic mass of energy is formed due to the increased oxidation of fat. After using its own fat reserves, the organism begins to expend the proteins of its muscles and internal organs. At first the proteins of the less vitally important tissues are expended, and only in the final (terminal) stage does the destruction extend to the myocardium and the central nervous system. The final stage is one of preagonal disruption of metabolism and the vital functions of the organism (five to seven days). During this stage depression of the central nervous system is manifested, the appetite is absent, and there is noticeable weakness and apathy, leading to a deep coma. The body temperature before the moment of death drops to 28°C. Starvation victims can be revived through feeding. No detrimental effects are observed after enduring starvation once. Incomplete starvation differs from total starvation in the economical destruction of the organism’s own proteins and the prolonged maintenance of nitrogen equilibrium. Complete and relative starvation is used in the treatment of obesity, and more rarely, of other diseases connected with disturbances of metabolism, such as rheumatism, gout, diabetes mellitus, hypertensive disease, atherosclerosis, gastric and duodenal ulcers, and bronchial asthma. There are not many observations concerning the use of complete and prolonged starvation for therapeutic purposes in various diseases. Investigations conducted by the Czechoslovak scientists V. Dolezal and M. Pipal revealed that in a number of persons who used restricted diets in connection with obesity, psychic disturbances were noted (euphoria, agitated state, and depression). The headaches, dizziness, nausea, sensation of weakness, and poor sleep that sometimes arise after three or four days of starvation are apparently explained by increasing acidosis. They easily pass after cleansing enemas, general massage, strolls, and the drinking of alkaline mineral waters (Bor-zhomi). The Soviet scientist A. N. Bakulev obtained a favorable effect by using starvation for four to 18 days in treating acute inflammatory diseases of the pancreas and biliary tracts, chronic coronary insufficiency, gastric and duodenal ulcers, and obesity. There has been no success in establishing the advantages of complete starvation over restricted diets. Restricted diets, in comparison with prolonged starvation, are more easily endured by the patient. Partial starvation that includes so-called reducing rations is used with favorable results for various diseases (for example, diseases of the cardiovascular system). In the early stages of complete starvation, there occurs an adaptive rise in the activity of the enzyme tributyrinase, which reflects to a certain degree the state of lipid metabolism. In respect to time, this coincides with the intensified mobilization of fat from depots. At later states of starvation the activity of tributyrinase decreases, which is apparently connected with the depletion of reserves of easily mobilized fat. These facts point out the necessity of limiting the length of starvation treatment to the precise moment when decrease in the activity of the lipolytic enzymes and increase in the activity of the aminotransferases begin. The clinical indexes indicating that the course of treatment by starvation is completed are the appearance of a hearty appetite, the disappearance of furred tongue, which then becomes dark red and moist, and an increase in the respiratory quotient while, at the same time, the level of basal metabolism remains the same. During the first days after the end of treatment by starvation, an achloride (low-salt, low-sodium, and low-chlorine), vegetable and milk diet, one containing a maximum amount of vitamins and mineral salts (excluding sodium chloride) is used, along with a gradual increase in the quantity and caloric content of the food. A repeated starvation treatment is easier to endure. Treatment by starvation may be carried out only under hospital conditions. REFERENCESMolchanova, O. P., and E. N. Ezhova. “Izuchenie dlitel’nogo golodaniia.” Trudy 1 Moskovskogo meditsinskogo in-ta, 1939, issue 16.Studies of Undernutrition: Wuppertal, 1946–49. (Medical Research Council, Special Report Series, No. 275). London, 1951. I. S. SAVOSHCHENKO starvationStarvationDefinitionDescription
Causes and symptoms
TreatmentPrognosisKey termsResourcesBooksPeriodicalsstarvation[stahr-va´shun]star·va·tion(star-vā'shŭn),starvation(stär-vā′shən)Neurology A paucity of neurologic activity Nutrition A condition resulting from prolonged deprivation of food, which occurs in abnormal environmental conditions—e.g., during war or famine—or in normal society through wilful neglect of others—e.g., children, the disabled or elderly by parents, family, care-givers or guardians—or by self-neglect in the elderly, mentally feeble, anorectics, or those who, irrespective of means, choose to live in apparent poverty; without food and water, the body loses 4–5% of its total weight/day and few survive > 10 days; when water is provided, a starving person may survive up to 60 days starvationNutrition A condition resulting from prolonged global deprivation of food, which occurs in abnormal environmental conditions–eg, during war or famine, or in normal society through willful neglect of others–eg, children, the handicapped or elderly by parents, family, care-givers or guardians, or by self-neglect in the elderly, mentally feeble, anorectics, or those who, irrespective of means, choose to live in apparent poverty; without food and water, the body loses 4-5% of its total weight/day and few survive > 10 days; when water is provided, a starving person may survive up to 60 days Clinical Hypovitaminoses, malnutrition, ↓ subcutaneous fat with thin, dry and hyperpigmented skin stretched over bone prominences, atrophy of organs, marked attenuation of the GI tract, with an enlarged stone-laden gallbladder. See Fasting, Minnesota experiment Neurology A paucity of neurologic activity. See Motion starvation, sensory deprivation.starvationLong-term deprivation of food and its consequences. These are severe loss of body fat and muscle, changes in body chemistry with KETOSIS and constant hunger.star·va·tion(stahr-vāshŭn)starvation
Synonyms for starvation
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