Jett, Ch. 3)
Programmed Aging Theories correct answers Suggest aging is the result of predictable
cell death. Commonly referred to as the Hayflick Limit or the Organs have a biological
clock. Suggests limited number of cell replications.
Neuroendocrine Control or Pacemaker Theory correct answers Explains aging as
programmed decline in the functioning of the nervous, endocrine, and immune systems.
Cells don't die, rather they lose their ability to reproduce. This process is called
replicative senescence.
Immunity Theory correct answers Failure to recognize self & tied to free-radical theory.
Describes aging as a programmed accumulation of damage & decline in immune
system function; also known as immunosenescence. The damage is thought to be the
result of oxidative stress.
Error Theories correct answers Propose that the aging phenotype is the result of an
accumulation of random errors in the synthesis of cellular DNA & RNA. Each replication
produces more errors until the cells no longer function.
Wear & Tear Theory correct answers One of the EARLIEST theories. Proposes that
cell errors are the result of "wearing out" over time because of continued use. Internal &
external stressors, pollutants, free radicals, metabolic by-products, etc. may cause
progressive decline in cell function.
Cross-linkage Theory correct answers Affects WOUND HEALING. Suggests aging to
be the result of accumulated damage from errors associated with cross-linked proteins.
Such AGE's (advanced glycation end-products). By a process known as glycosylation or
glycation, cellular glucose attaches to protein creating a stiff and thick bond.
Oxidative Stress Theory (Free Radical Theory) correct answers First proposed by D.
Harman(1956). Suggest that the errors are the result of random damage from free
radicals. Free radicals are highly reactive to molecules in the cell membrane.
Mitochondrial DNA appears to be most affected by oxidative damage. Simply, over time
the production of free radicals increases and the body's ability to remove them
decreases. THEY ARE BYPRODUCTS OF CELLULAR METABOLISM.
Promoting healthy aging correct answers Slowing or reducing cellular damage -most
potential