Ageing L26 Flashcards
What is the worldwide average life expectancy
67.2
Why do women live longer than men
1) Delayed onset of cardiovascular disease in women
2) Women have lower iron levels than men (due to menstruation) – iron is involved in the formation of damaging free radicals
3) Young men engage in risky behaviour
4) 2 X chromosomes makes it less likely that some deleterious mutations on the X chromosome are expressed
What is thought to be the reason why women have a delayed onset of cardiovascular disease in women
Oestrogen production
What is ageing
Decline in the function of various bodily systems
Humans are unlikely to live beyond 100-110 years due to what factors
1) genetically programmed cessation of mitosis
2) damage to the body’s DNA,
3) breakdown in the accuracy of protein synthesis,
4) changes in neuroendocrine function,
5) decline in immune function,
6) an increase in cellular free radical injury.
What are the cellular/morphological changes associated with ageing
1) Cell loss (significant in amitotic tissue such as corneal endothelium) and loss of skeletal and smooth muscle (e.g. iris dilator muscle
2) Changes in cellular organelles (e.g mitochondria and ER)
3) Accumulation of lipfuscin
4) Accumulation of Advanced Glycation End products (AGEs)
5) Irreversible DNA damage
What does accumulation of advanced glycation end products do
Cause cross-linking between proteins (cross-linking between crystallines is associated with cataract)
What is a telomere
Repetitive nucleotide sequence at the ends of chromosomes
What happens to telomeres as people age
Telomere length declines in dividing cells as we age
What are the connective tissue changes associated to ageing
1) Elastic tissue changes (e.g wrinkles and loss of arterial elasticity leads to increase blood pressure)
2) Enzymes that destroy collagen up regulated
3) Changes in cartilage
4) Loss of bone
5) Hair
What are the reproductive system changes associated to ageing
1) Menopause
What are the multi sensory detoriations associated to ageing
1) Vision, semicircular canals, hearing (presbycusis), taste, smell, pressure, temperature, proprioception & pain (loss of corneal sensitivity with age)
What are the risks of associated with immune system decline
1) Increase chance of infection in the elderly
What does the proximate cause mean
An immediate trigger
What does the ultimate cause mean
The evolutionary explanation
