Aging, the Aging Process and its Impact on Physiological Systems Flashcards
(33 cards)
What is biological ageing?
A complex biological process causing progressive decline in the body’s ability to respond to stress due to molecular, cellular, and organ-level changes.
What are the two main categories of ageing theories?
Programmed (genetic, hormonal) and stochastic (random damage, error theories).
What is the programmed theory of ageing?
Ageing is driven by a biological clock regulated by genes and hormones.
What is the non-programmed (stochastic) theory of ageing?
Ageing results from random molecular damage over time, including DNA and protein damage.
How does the evolutionary theory explain ageing?
Selective pressure acts only until sexual maturity, allowing late-onset diseases to persist.
What gene mutation causes Hutchinson-Gilford Progeria?
LMNA gene mutation affecting nuclear envelope protein lamin A.
What is Werner syndrome?
A premature ageing disorder due to WRN mutation affecting DNA helicase involved in DNA repair.
Name 9 cellular & molecular hallmarks of ageing.
Genomic instability, epigenetic changes, loss of proteostasis, mitochondrial dysfunction, deregulated nutrient sensing, cellular senescence, telomere attrition, stem cell exhaustion, altered intercellular communication.
What causes genomic instability in ageing?
External and internal DNA damage including from reactive oxygen species.
What are epigenetic changes in ageing?
DNA methylation, histone modification, and chromatin remodeling that affect gene expression.
What is proteostasis loss and how does it relate to ageing?
Impaired protein folding and clearance, leading to aggregates like amyloid and cellular dysfunction.
How does mitochondrial dysfunction affect ageing?
Leads to decreased ATP, increased ROS, and oxidative damage.
What is deregulated nutrient sensing?
Disruption in insulin/IGF and mTOR pathways, affecting metabolism and ageing.
What is cellular senescence?
Permanent cell cycle arrest; senescent cells can secrete inflammatory cytokines.
What are telomeres and their role in ageing?
DNA repeats protecting chromosome ends; shorten with each division, contributing to senescence.
What enzyme counteracts telomere shortening?
Telomerase.
What is stem cell exhaustion?
Decline in regenerative capacity of tissues due to reduced stem cell function.
What is ‘inflammageing’?
Chronic low-grade inflammation due to accumulated senescent cells and reduced immune clearance.
How does ageing affect the respiratory system?
Loss of elastic recoil, reduced surface area, reduced compliance, decreased FEV1 and tidal volume.
How does ageing affect the cardiovascular system?
Arterial stiffening, increased systolic pressure, LV hypertrophy, arrhythmias, reduced contractility, baroreceptor sensitivity.
What nervous system changes occur with ageing?
Brain volume loss, synaptic reduction, neurotransmitter decline, motor/sensory conduction loss.
What are key musculoskeletal changes with ageing?
Sarcopenia, joint stiffness, reduced bone density.
What endocrine changes occur with ageing?
Reduced hormonal responsiveness, impaired circadian rhythm, increased stress hormones.
What immune changes occur with ageing?
Immunosenescence, reduced T/B cell function, increased autoimmunity.
