Appetite - emotional expression food needs. Occurs appetite based on the state of hunger (see).
The most marked changes occur in the activities of organs of digestion. There are a selection of saliva and gastric juice ("delicious", or the firing, in the words of I. P. Pavlov), and peristaltic movements of the stomach and intestines. Increased activity of the digestive system, in turn, enhances the feeling of appetite.
Manifestation of appetite depends on the excitation of food center and other structures of the Central nervous system and the body's overall health. Positive emotionscaused by a pleasant environment, particularly related to food intake, increase the appetite, strong negative emotions (fear, disgust) - suppress it. The same braking effect on appetite has the initiation of a number of nerve centers (e.g., vomiting, urinating, defecating). A person appetite often occurs under the influence of conditional stimuli associated with the ingestion: furnished, odour appearance of food, the time of its reception. Different people have individual fluctuations of appetite, depending on the kind of work, leisure, mode and conditions of the meal, its composition.
Changes in appetite observed at various common diseases (infections, metabolic and psychological diseases) and diseases of the digestive tract as towards reducing appetite to complete blindness (anorexia), and in the direction of the extraordinary increase appetite, called polyphagia. Treatment of disturbances of appetite - see Anorexia, Polyphagia

Appetite (from lat. appetitus - aspiration, desire) is the emotional expression of the body's need for nutrients. Appetite is closely connected with the state of hunger (see). However, if the condition of hunger, as a rule, is accompanied by unpleasant emotions of the character, then, in contrast, emotional manifestations of appetite always defined pleasant sensation of taste those nutrients that the body needs. Often under the appetite meant also the degree of positive emotions, which directly accompanies the meal. Appetite may occur not only when, but in the absence of real food irritation under the influence alone situational stimuli.
Unlike hunger, appetite is not innate, but acquired in individual life. The newborn appetite is formed only after the child's sense of hunger is one or more times satisfied with the meal. The result is unpleasant emotions hunger start to accompany pleasant thoughts on the future of food irritation that from the biological point of view, is a powerful factor contributing to finding food and its better assimilation by the organism.
Appetite is always formed on the basis of certain physiological mechanisms that clearly objectively manifested in the change of activity of special nerve structures, in the activities of numerous vegetative organs and motor reactions (targeted traffic to food, the contraction of mimic muscles, and so on). The most demonstrative in this case changes in the digestive organs. As a rule, the appetite by increasing the secretion of saliva and gastric juice ("delicious", or "glow", juice by I. P. Pavlov).
The emergence of appetite closely related to the work of food center (see Digestion). Numerous studies have established that the Central point of the complex food center is the hypothalamus area. There is a perception that the excitation of hypothalamic structures food center at the expense of the ascending activating effects selectively involves special cortical synaptic education and this determines the electoral feeding behavior. Appetite as subjective manifestation of excitation of food center is caused by activities not only in the nervous system of a bark of the big hemispheres, but the limbic system of the brain. Because your appetite is closely connected with the state of hunger, one of the main reasons for its occurrence is automatic irritation special receptor formations hypothalamus blood depleted nutrients ("hungry blood"). However, a significant role in the emergence of appetite play and nervous factors that can influence food center as "bottom"- from the digestive organs, and "from above" - on the part of the cerebral cortex.
There are two forms of appetite: 1) General (emotional reaction to food in General); 2) election (the body's response to certain types of food). As a rule, electoral appetite arises in connection with absence in the internal environment of an organism of those or other nutrients, acids, salts and vitamins. This appetite is often observed in children, pregnant women and patients with malignant tumors. In some cases electoral appetite can proceed in the form of perverted A. (pica), when the body begins to feel the need for such substances, which are normally not used (kerosene and even metallic objects). Often the cause of perverted appetite are psychological diseases.
Appetite disorders conditionally can be divided into two groups: 1) anorexia (see) - reduce feelings of hunger and appetite; 2) bulimia - a sharp increase in feelings of hunger and appetite. Appetite disorders are observed for tumors of the brain, while the number of endocrine diseases (diabetes mellitus, thyroid goiter disease Simmonds and others), as well as some functional diseases of the Central nervous system (hysteria, psychosis, etc.,). Often the cause of the disorder A. are diseases of the gastrointestinal tract (gastritis, enteritis, hepatitis), and avitaminosis. Various diseases are often accompanied by disorder A. that may be one of symptomatic signs.
Appetite can be suppressed various external influences and experiences: the pain, fear, anger, suspense, and so on, So the state A. may characterize a state of the person. Good A. often demonstrate his physical and mental well-being. In normal conditions improve A. you can achieve by following a strict food, quality improvement, cooking, feeding bitterness and improves the taste of food spices. For the favorable impact A. the digestive process needs during the meal to eliminate all distractions (haste, reading etc). Neglect of appetite is often the root cause of many so-called neurogenic diseases of the gastrointestinal tract. Cm. also Motivation.