Neuroscience Speech

Memory in aging (Topic 1-3)

Topic1 physiological changes

In the last three decades the older adult population (>65 years of age) has grown twice as fast as the rest of the population. The Australian Census conducted in 2001 found that 12.5% of the populations were aged 65 or older. Several factors have led to this overall increase in the older population worldwide. Those such as the immigrant from World War II are now grown older and also the improvement in technology and medicine. Drug therapies including antibiotics and chemotherapy, and improved public health and nutrition have contributed to the increase in life span. Therefore life expectancy has rise and most Australian can expect to live as average of 80 years. Males and females born in 2001 can expect to live for 77 and 82 years, respectively.

From a biological view, aging can be defined as the progressive loss of function. This age related decrease occurs along with decreasing fertility and increasing mortality. Biological aging is clearly a multifactorial process involving genetic, oxidative stress, diet and environment.

Aging does not inevitably lead to disease and disability. Many older people remain functionally independents despite the increasing prevalence of chronic diseases. However, chronic diseases do increase the older adult’s vulnerability. Age-related changes affect every body system. Those changes are normal and occur as people age. The table below presents age-related physiology changes and associated clinical manifestations

SYSTEM | EXPECTED AGING CHANGES | CLINICAL MANIFESTATIONS |

Cardiovascular * Cardiovascular output * Structural changes | * Force of contraction decreased * Fat and collagen increased * Heart muscle decreased * Ventricular wall thickened * Aortic valves sclerotic and calcified * Baroreceptor sensitivity decreased | * Myocardial oxygen demand increased * Stroke volume and CO decreased * Fatigue, Shortness of breath, tachycardia...