Aging (or senescence) is that period of life, characterized by a series of progressive irreversible changes affecting the cells,
tissues and organs, therefore of the whole organism, which begin when this, once development is complete, has reached a
adulthood, and continue to manifest themselves, culminating in death, which occurs as a consequence of them and not by
the intervention of external factors. Gerontology is the biological discipline that studies this process, which can be
considered both physiological, because it is normally present in the life span, and pathological because it causes disturbances.
he senile alterations, found in many organs are quite distinct from the pathologies affecting the elderly; the branch of
medicine, called Geriatrics, deals with the study of these whose appearance is certainly facilitated by the modifications caused
by aging. Lifespan: he reduction in life span seems to always be due to a greater production of free radicals (defined as ROS =
Reactive Oxygen Substances). In reality, a certain amount of ROS is physiologically formed in the body’s cells, hence the
excessive production of these or their poor elimination has been considered one of the most significant causes of aging due to
the fact that these free radicals interact with nucleic acids, proteins, and lipids, altering them structurally and functionally. the
only cells that can have a maximum life span equal to that of the organism to which they belong are perennial or post-mitotic
cells (neurons and muscle cells), that is, those without replicative activity.