Physiology Flashcards
What is the definition of ageing
Progressive, generalised impairment of function resulting in a loss of adaptive response to disease
What causes ageing
Random molecular damage during cell replication
Inactivity, poor diet, inflammation increase damage
Overall this reduces the body’s adaptive reserve capacity
Loss of biological reserve
What is cell senescence
The point where they stop dividing
How do telomeres contribute to ageing
Telomeres are found at the end of each chromosome and shorten slightly each time the cell divides
It is though the telomeres have a protective quality
As we age, cells divide more and more and eventually the telomeres become too short to sustain replication
Can telomeres be used to estimate age
YES
They can give a rough estimate
What can cause damage to macromolecules such as DNA and impact ageing
Ionising radiation
Reactive oxygen species - come from diet, radiation and inflammation
Extrinsic toxins
Cellular damage leads to 1 of 4 responses, what are these 4
Repair
Apoptosis
Senescence
Malignant transformation
What are some the evolutionary explanations of ageing
Maintaining a body takes up a lot of energy and resources
Once we have reproduced there is less need for this so limited resources go to offspring
What does frailty increase your risk of
Falls Delirium Disability Death Hospital complications Takes a lot longer to recovery from illness/trauma
How can lifestyle choices affect ageing
A healthy lifestyle can increase survival
Physical activity, not smoking and being in a social network increase chance of survival
How does ageing affect weight and muscles
Decrease of muscle mass - particularly in quads due to immobility
Loss of bone mass
Increase in fat and fibrous tissue
Overall deconditioning
Associated condition - sarcopenia
How does ageing affect the brain and cerebrovascular system
Decrease in cerebral blood flow and autoregulation becomes more defective
Daily neuronal loss and decrease in brain weight
Associated conditions - TIA, stroke, delirium, dementia
How does ageing affect the autonomic nervous system
Becomes less reactive which affects the control of BP and temperature
Associated condition - Hypothermia, Postural hypotension (increase risk of fall)
How does ageing affect bones and joints
You get a gradual and progressive loss of bone from age 35
Lots of elderly have symptoms of OA
Associated conditions - osteoporosis, decrease mobility, arthritis
How does ageing affect the cardio-respiratory system
Decreased CO, SV, HR An increase in intracellular collagen leads to LVH and decreased LV compliance Decreased vessel wall distensibility Calcification of heart valves Decreased lung compliance, capacity
Associated conditions - loss of fitness, HTN, cardiac failure
