Periodicum biologorum, Vol. 115 No. 4, 2013.
Review article
Aging
ZIJAD DURAKOVIĆ
; Department of Medical Anthropology and Epidemiology, Institute for Anthropological Research, Ljudevita Gaja Street 32, 10000 Zagreb, Croatia
Abstract
The paper deals with changes of human organism during physiological
aging. Initially changes occur in internal organ function, followed by morphological changes of particular organs. The body start showing signs of growing old at the beginning of the fourth decade. Some organs age faster as the kidneys, while others age slower such is the liver. Among the general changes which occur along with aging, body mass increases as a result of fatt tissue increase, but decreases in highly advancing age. Changes of body water also occur and is reduced by about 10–15 % in comparison to middle-aged persons. The human body contains more extracellular than intracellular
water and that is why is greater plasma volume with advancing age. The quantity of the connective tissue in heart muscle increases, particularly in the endocardium and the epicardium, while the pigment lipofuscin is deposited in the myocardium. From the beginning of the fourth decade, cardiac output decreases by about 1% yearly, stroke volume decreases for about 0.7%, and peripheral vascular resistence increases for about 1.2% yearly. In the respiratory system, from the fourth decade the number of cilia diminish, alveolar macrophages are less efficient, lung elasticity decreases, sternocostal joints
became inelastic, chest expansion is diminished, the speed of expiratory air can be reduced. In the kidneys changes in blood vessels leading to the alteration of nephron function. The number of capillaries dwindles, influencing both glomerular and peritubular parts, the total weight of the kidneys can be reduced, the connective tissue increases as the basalmembrane become thicker. Glomerular capillaries degenerate and are bridging by arterioles. Other internal
organs change with advancing age also.
Keywords
Hrčak ID:
116445
URI
Publication date:
31.12.2013.
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