الفهرس 
PHYSIOLOGY OF AGINGOnly 14 pages are availabe for public view
 |  | from | 170 |  |  |
| | | from | 170 | | |
Abstract
Aging is a progressive universally prevalent physiological process that produces measurable changes in the structure and decremental alteration of the function of tissues and organs.
Changes that are not universal or that do not increase in severity or magnitude in proportion to chronologic age are probably not manifestations of aging but, rather, are usually signs or symptoms of age-related disease. Example of major changes that are considered physiological in elderly subjects include, altered cerebral blood flow autoregulation, decline in afferent and efferent nerve conduction velocities and the rate of signal processing within brain stem and spinal cord, elevated both plasma epinephrine and norepinephrine at rest and in response to stress, reduced responsiveness of autonomic end-organs, decreased response of the cardiovascular system to beta-adrenoreceptor stimulation, decrease in lung recoil, decreases chest-wall compliance, maldistribution of pulmonary blood flow relative to distribution of tidal volume, linear decrease in arterial oxygen tension, decrease in anesthetic requirements and altered pharmacokinetic and pharmacodynamics of many of the drugs used in anesthesia.