Sum of all changes occurring in an organisms over time phase of normal life cycle
or: Sum of all changes occurring with time and leading to functional impairment and death
or: Changes with time in membranes, cytoplasm and/or nucleus
Outline of first lecture:
Demography of aging:
* Increasing in average lifespan from middle of 18th cantury to end of 20th century.
* Increased lifespan in all countries (Developed and Underdeveloped)
* Longer lifespan in women than men
* Fastest growing proportion of the population +80 years
* Increased maximal lifespan
* Compression of morbitity (pg. 26 PBAG)
|Country/Time Period||Life expectancy (at birth)||Infant mortality (per 1000)|
Life expectancy in the U.S. in 1900: Men 45 and Women 48
Life expectancy in the U.S. in 1990: Men 73 and Women 78
|United Kingdom 78.7||5.0|
Genetic (XX vs. XY phenotype)
Environmental (geography, country, income)
Some causes include:
1. Lesser life stress in females, hence lower incidence of cardiovascular diseases
2. Less smoking (although the numver of women smokers is on the increase in several countries)
3. Protective action of estrogens (e.g. on cardiovascular system)
4. Higher gene recombination frequency
5. Lesser accumulation of mDNA deletions.mutations with better proection against oxidative damage
* decreased physiological competance with aging?
* increased pathology and mortality with aging (Gompertz Law pg. 24)
"The older we get, the faster we get old"
* however, great heterogeneity of the aging process has led to three trajectories:
* mechanism of successful aging include:
* Previously, most people died from acute infectious diseases, often in childhood.
* Currently, most people die from chronic degenerative diseases, usually at older ages.