Basic science Flashcards
Normal aging
- Decline and deterioration of functional properties at cellular, tissue and organ level
Successful aging
- Physical, mental and social aging in old age
Biological aging
- Using biological principles to explain the process that occur as the body ages
- Apoptosis/ DNA repair
- Dysregulation of cellular pathology
- Senescence
- Increased inflammatory markers
Aging
- Progressive decline in cellular mechanisms of homeostasis
- Decreased ability to adapt to stimuli, disease and mortality
Disease
- Disorder of structure or function
- Produces signs and symptoms
Age associated disease
- Increasing disease frequency with increase senescence
Frailty
Genetic syndrome
- Weakness, wt loss, low activity
- 5 criteria:
- Exhaustion, slowed speed, weakness, wt loss, low phys activity
Biology of frailty
- Apoptosis dysregulation
- Pro-inflammatory states, senescence
- Tissue repair deficits
Senescence- definition
- Irreversible arrest in cellular proliferation
- Normal cellular response to cancer like events
- Telomere shortening
Senescence- Influence on aging
- Accumulate with old age, present at sites of pathology
- Contribute to pro-inflammatory state
Apoptosis- Definitions
- Orderly process of programmed cell death
- ATP dependent process
Apoptosis- Infuence
- Failure leads to rogue cell proliferation
- Decrease in ATP leads to necrotic cell death over apoptosis
- Increase in inflammation and frailty
Inflammation- Def
- Sentinel response to stressors
- Heat, pain, redness, swelling and loss of function
Inflammation- Influence in aging
- Deregulated in frailty
- Affect growth hormone axis- fatigue, malaise, sleep, disinterest
- Facilitates disease progression
Epi/genetic aging theory
- Chemical reactions that direct transcription, gene expression
- Methylation increases with age, hypermethylation leads to transcription silencing
- Increased senescence
Somatic mutation
- No selective pressure on older, post-reproductive age
- Decline in force of natural selection with age
- Detrimental effects of late acting genes lead to aging
Error- catastrophe theory/ protein error
- RNA is damaged during aging
- Leads to protein destabilization, loss of molecular function
- Protein loss leads to biologic changes associated with aging
Free radical
- Free radical exposure increases through lifespan
- Mechanisms to handle free radicals decrease through lifetime
- by metabolic rate
Replicative senescence/ telomere senescence
- Gradual loss of telomere activity
- Cells enter senescence
- Pro-inflammitory cytokines increase
Mitochondrial damage
- Change in mtDNA has adverse effect on mitochondria
- Less energy, more free radicals, accumulation of harmful molecules
Wear and tear/ rate of living
- Finite amount of vital substance
- Death = using all that substance
- Rate of metabolism?
Immunologic
- Declining immune fxn disrupts homeostasis
- loss of thymus, T-lymph, ability to produce abs
Natural selection
- Aging is adaptive to allow survival of young, at detriment of post-reproductive people
- Detrimental late-acting genes build up over time
GI organ changes
- Increased dysphagia, less HCl
- Increased transit time, diverticula constipation
- Decreased vit B12, iron, Ca absorption
CV organ changes
- Increased fatty deposits, increased myocardial hypertrophy
- Heart more stress, less quick to respond
Urologic organ changes
- Decreased kidney size & fxn, GFR
- Cant resorb glucose, concentrate urine- dehydration
Musc organ changes
- Decreased contractility, smaller fibers, fewer type II fast twitch, strength
- Decreased bone density, stiffer joints, degeneration
Cognitive organ changes
- Fewer neurons, speed of processing
- Atrophy of cortices, lobes and structures
- Slower at tasks, rxn times
Resp organ changes
- Decreased elastic activity, vital capacity
- Increased residual volume
- ## Begins to decline after 35 yrs
Integumentary
- Skin thins, loss of elasticity
- Wrinkling, dryness
- Envt exposure increases aging
- Loss of fat later
Endocrine/ reproductive
- Decreased testosterone and estrogen = increase fat, decrease muscle
- Increased dryness, pH
- Hypertrophy of prostate
