Old age, aging

Old age and aging. Old age is imminent, the coming change of maturity period of life of humans and animals, characterized by reduction of compensatory opportunities and the reactivity of the organism.
Old age is the result of a dynamic process of aging.
Ageing is a long biological process of aging of the organism, beginning long before old age, and inevitably leading to a gradually increasing restriction of adaptive opportunities of an organism and increase the chance of death. Age-related changes at the cellular and sub-cellular and molecular levels, in different organs and systems develop at exactly the same speed and uneven.
Aging is internally inconsistent. Along with the decline, the weakening of one process is the strengthening of the other. Thanks to develop new compensatory mechanisms can, however, only to a small extent replace any pre-existing compensation mechanisms.
There are two types of aging - physiological, mentioned above, and pathological (premature). Premature or pathological aging occurs at a relatively young age as a result of prolonged action on the human organism of some of the harmful factors of the external and internal environment (sickness, injury, severe domestic and industrial conditions, alcoholism, adverse heredity, etc.), accelerating the course of normal physiological aging.
The nature and course of physiological aging largely determine the duration of the natural life of man. It is believed that the potential lifespan of a person must exceed 100 years. However, cases of physiological, i.e. natural, old age is still rare. The average life expectancy is currently in the USSR is for men to 65 years and for women - 74 years. Study of age-related changes in various organs and tissues of the human body allowed to come to the conclusion that the elderly are people aged 60 to 74 years, and old age begins after 75 years. People 90 years and older are called long-livers.
What prevents a person to live a life possible longevity? There are numerous theories as to the cause of aging. Followers of some theories of the old age is explained by changes of any internal organ or system: the endocrine system, nervous system, connective tissue. Adherents of other theories acknowledge the leading factor in aging-intoxication of an organism products of an exchange. Many researchers have suggested on the accumulation throughout the life cycle of the organism so-called errors synthesis of proteins and nucleic acids, which is reflected in the structure of the molecules of these compounds.
The old man is characterised by significant changes in various organs and systems. Changing the look, mind, behavior. Movement loose their smoothness, joint mobility is limited, reduced muscle strength. Hair's turning gray, becoming rare and fragile. Skin becomes thin, becomes less elastic, wrinkles appear. Among the elderly is reduced mental performance, easier occurs fatigue, weakened memory, sleep disturbance. The sensitivity of tissues and organs to nerve influences diminish, and by humoral - rises.
In old age, there are significant changes in the function of the cardiovascular system. The heart rate slows down, vascular reactions become more inert. The arteries become thick, brittle, tortuous. The formed elements of blood and red bone marrow is the spongy bones not undergo any significant morphological changes. In the lymph nodes develop atrophic processes. In light of older people observed senile emphysema, resulting in reduced their vital capacity. With age disturbed activity of the gastrointestinal tract. The mucous membrane of the mouth becomes very thin teeth comes out. The stomach is reduced by old people, mucous membrane it thinned, smoothed the folds. Tooth decay affects the mechanical processing of food in the mouth. Receipt in the gastrointestinal tract badly chewed food is bad for the digestion of food. Coming in old age change the function of the digestive system may be one reason for the development of vitamin deficiency.
Pathological processes flowing slowly and sluggishly. For this reason the hidden currents of diseases, their frequent bessimptomnom indicating about a General decline in the levels of reactive processes. Decided to allocate the disease, the development of which is directly associated with the aging process. These diseases as a disease of old age, the so-called degenerate, especially frequent in the circulatory system and musculoskeletal apparatus.
The study of aging of the organism involved in biomedical science - gerontology (see), its clinical branch was named geriatrics (see).