1.1 Flashcards
(31 cards)
What are some key contributors to increased human lifespan over the past 200 years?
Advances in public health such as improved sanitation, nutrition, clean water, economic growth, poverty reduction, and education—as well as breakthroughs in medicine (better neonatal care, antibiotics, vaccines, surgery, and device technology)—have driven the increase in lifespan.
How has life expectancy changed from the 1800s to today?
In the 1800s, the average life expectancy was about 40 years; today, it is around 70 years globally, with developed regions like Australia and Europe experiencing even higher averages.
What is ‘period life expectancy’?
Period life expectancy is a metric that summarizes age‐specific death rates in a given year, representing the average lifespan a hypothetical individual would have if the current death rates persisted throughout life.
How do public health improvements contribute to increased lifespan?
Improvements such as better sanitation, clean water, nutrition, and health education have reduced early mortality and disease burden, thereby extending average lifespan.
How has the demographic profile shifted in developed countries due to increased lifespan?
A lower reproduction rate combined with increased life expectancy has resulted in a larger proportion of older adults (over 65) and a smaller proportion of children (under 15) in developed countries.
What key age-related changes occur in the cardiovascular system?
The cardiovascular system undergoes reduced cardiomyocyte numbers, decreased heart rate and pacemaker function, increased arterial stiffness, plaque formation, and reduced wall elasticity, all culminating in compromised cardiac output.
What formula is used to estimate maximal heart rate decline with age?
Maximal heart rate is generally estimated using the formula mHR = 220 – age.
How does ageing affect the structure of the brain?
With ageing, the brain experiences a decline in total volume, deterioration of the myelin sheath, a reduction in regions like the temporal lobe and hippocampus, and an increase in ventricular volume.
What musculoskeletal changes occur as part of ageing?
Ageing leads to decreased bone mineral density (resulting in brittle bones), reduced muscle mass and power, thinning cartilage, stiffer ligaments and tendons, plus altered posture and gait.
How prevalent are fragility fractures in older adults, and why do they occur?
Fragility fractures occur in about 1 in 3 females and 1 in 5 males over 50 due to a decline in bone density and changes in bone composition.
Despite earlier declines in physical functions, why do women typically outlive men?
Although women may experience earlier drops in bone density and muscle strength, they are generally more resilient to mortality risks at every age, resulting in a higher life expectancy compared to men.
What cardiovascular chronic diseases become more common with age?
As people age, conditions like heart attacks, strokes, and other heart-related diseases become more prevalent due to reduced heart function, arterial stiffness, and the development of atherosclerosis.
What changes in the respiratory system are observed with ageing?
Ageing of the respiratory system includes decreased alveolar elasticity, enlarged alveoli, and diminished cilia function, which can reduce cough strength and overall respiration efficiency.
At what approximate rate does brain volume decline during mid-to-late life?
Brain volume typically decreases by around 3% per decade during mid-to-late life.
What is ‘inflammaging’, and how does it relate to the ageing process?
Inflammaging refers to the chronic, low-level inflammation associated with ageing, which contributes to tissue degradation and decreased organ function over time.
Why are non-human models important in lifespan research?
Non-human models allow researchers to study lifespan and the underlying mechanisms of ageing in organisms that share key genetic and physiological similarities with humans but have shorter lifespans, enabling quicker experimental cycles.
Which non-human model shares about 90% of its genetic material with humans and has a lifespan of roughly 7 years?
Mice share about 90% of their genetic material with humans and typically live for around 7 years, making them a valuable model for ageing research.
What makes C. elegans a valuable model for studying ageing?
C. elegans are ideal for ageing research because they have an extremely short lifespan (2–3 weeks) and still share fundamental genetic pathways with humans that control lifespan and ageing.
How does genetic similarity influence the choice of non-human models for lifespan studies?
Models with higher genetic similarity to humans (e.g., non-human primates with ~99% similarity) provide more directly translatable insights into human ageing, although practical factors like lifespan duration must also be considered.
What are the primary components of human health that define lifespan according to this lecture?
Key components include the health of the cardiovascular, musculoskeletal, and nervous systems—each influencing the risk of chronic diseases and overall quality of life as humans age.
In what ways have public health measures extended human lifespan?
Public health measures have reduced infectious diseases and early mortality through improved sanitation, access to clean water, better nutrition, and widespread health education.
How does brain ageing contribute to the development of dementia?
Structural declines in the brain, such as reduced volume and deteriorated myelin, along with loss of key brain regions, increase the risk of cognitive impairment and dementia.
What cellular changes are common across organs during ageing?
Common changes include a reduction in cell numbers, alterations in tissue structure, decreased cellular function, and an increase in chronic inflammation.
How do lifestyle improvements and medical advancements interact to extend lifespan?
They work synergistically—lifestyle improvements reduce the exposure to many disease risks, while medical interventions manage acute and chronic illnesses that could shorten life.
