Ageing of body systems Flashcards
What is ageing?
has biological and social impacts however these are individualised and differ between people
biological-
- the gradual accumulation of molecular and cellular damage overtime, leading to decrease in physiologcal function and increase in various diseases
- a general decline in the capacity of the individual, leading to death
social-
- social role, position, and relationships change
- goals and activities change
- development of new roles, viewpoints, and different social contacts
What are the 9 hallmarks of ageing?
(Lopez-Otin, et al, 2013).
- Genomic instability- the accumulation of genetic damage altering the genetic control of cellular function.
- Telomere attrition- telomeres are progressively shortened with each replicative cycle. Once lost, further replication of the cell is not possible and it will die.
- Epigenetic alteration- alterations on gene expression affects the enzymes within the cells and so change the way cells work.
- Loss of proteostasis- decline in ability of cells to maintain proper protein folding and degradation, therefore affecting function
- Deregulated nutrient sensing- reduction in control of nutrient use within the cell, leading to metaboilic dysfunction
- Mitochondrial dysfunction- decline in mitrochondryia function, effecting cells energy production
- Cellular senescence- stopping the cell cycle at a stable point, resulting in the cells no longer being able to divide, overtime tissue will accumulate senescent cells with a reduction in its function.
- Stem cell exhaustion- Reduction in the regenerative capacity of stem cells, which play a key role in tissue repair and maintenance
- Altered intercellular communication- reduces the bodies ability to response to damage and stimuli.
first 4 are causes of damage, next 3 are responses to thr damage, and last 2 are consequences that ensue with ageing.
What is the WHO definiton of healthy ageing?
(WHO, 2015)
“the process of developing and maintaining the functional ability that enables well-being in older age.”
emphasizes importance of maintaining physical, mental, and social well-being as people age.
it highlights the idea that aging is not just about lifespan, but also about quality of life.
How does ageing affect the reproductive system?
(Hall, 2021)
- testosterone decline in men
- enlarged prostate, causing problems in passing urine
- menopause ends fertility in women- men can father children later into life 60s-70s
- reduced oestrogen production in women
- libido decreases with age- can cause relationship problams if partner mismatch
How does ageing affect the endocrine system?
(Hall, 2021)
- decline in endocrine function- recued hormone sectretipn, responsiveness to hormones, and changes in central control
- this can lead to changes in other systems
How does ageing affect the renal and hepatic system?
(Hall, 2021)
- reduced filtration rates cause decline in renal function
- functional changes in renal tubules mean you are less able to concentrate or dilute urine and control excretion of drugs
- a 25% reduction in liver weight from 25-60 years
- results in reduced clearance of drugs
How does ageing affect the gut?
(Hall, 2021)
- gut microbiome changes- may cause irritation
- reduced effecincy in oesophgus causing dysphagia and reflux consequences
- stomach becomes less complaint with delayed emptying, reduced acid production and feeling full after eating small amounts
- transit time in colon is increased, reducing peristalisis, increasing water reabsorption and making people more p[rone to constipation.
How does ageing affect the nervous system?
(Hall, 2021)
- neurodegenerative and cognitive decline
- 50% of adults over 85 have Alzheimer’s
- decline in sensory functions- taste, smell, sight, hearing affected
- decline in motor functions- slower reaction time, slower central processing and movement, affect posture and balance
- slowing of central processing in NS, decline in short-term recall, however normal ageing of the brain occurs in the absense of disease
How does ageing affect the musculoskeletal system?
(Hall, 2021)
- age is biggest risk factor in oestoporosis and osteoarthritis
- increased risk of bonefracture
- loss of muscle mass
- progressive reduction in support as posture changes
- decreased strength and physical ability
How does ageing affect the cardiovascular system?
(Hall, 2021)
- raasied systolic and pulse pressures due to progressivley rigid, large elastic arteries
- increased cardiac work and oxygen demand
- left ventircular hypertrophy- as heart is working harder to move blood through systemic circulation
- delayed baroreceptor responses- causing poor adaption to pressure changes
How does ageing affect the respiratory system?
(Hall, 2021)
- decreased elastic recoil of lungs, rigid chest wall and reduced force from respiratory musculature resulting in lungs not emptying fully
- this causes an increased functional residual capacity (FRC)
- smalll airway closes at earlier, at higher volume allowing less ventiliation at the base of lung
How does ageing affect the skin?
(Hall, 2021)
- influenced by genetics, environmental exposure, hormonal changes, metabolic processes
- skin becomes thinner
- rate of regeneration becomes slower
- greater risk of breakdown
- reduction in collagen and elastin causing dermis to become thinnger, stiffer, and less malleable, less elastic
How does ageing affect the nerves?
(Hall, 2021)
- neuronal cell loss occurs
- changes in synpases
- plastcity, not replacement of neurones (rearranging the connections of lost neurones to take over functions)
How does ageing affect bone and connective tissue?
(Hall, 2021)
- decalcification of bone increases, reducing bone strength
- thinning of cartilage at joint surfaces
- elastic ligaments lose elastic element
- changed inevitable but can be delayed with exercise
How does ageing affect muscle?
(Hall, 2021)
- reduction in number of muscle fibres, fibre size, and replacing active muscle fibres with non-contractile fiburos tissue
- rapid loss of muscle mass after 60
- senile sarcopenia- increases fat, less effecient mitochondria, less blood flow, reduced number of motoneurons
