The Ageing Process

Question 1

what is the definition of ageing?

Answer 1

progressive, generalised impairment of function resulting in loss of adaptive response to disease

Question 2

what causes ageing?

Answer 2

random molecular damage during cell replication

reduction in body’s adaptive reserve capacity (resilience)

Question 3

what increases cell damage during replication?

Answer 3

inactivity
poor diet
inflammation

Question 4

what leads to cells senescence (cells cease to divide)?

Answer 4

telomeres shorten with each cell replication until they become too short to sustain replication

Question 5

what is the name given to the theory which is suggested as a limit to ageing?

Answer 5

the hayflick limit

Question 6

what is the downfall of the hayflick limit?

Answer 6

most human cells do not divide enough for this to be a limiting factor

nevertheless, telomeres is still a marker of age

Question 7

what is the ribonucleoprotein complex that can re-extend shorten telomeres?

Answer 7

telomerase

Question 8

in what kind of cells is telomerase more active?

Answer 8

cells such as immune cells and stem cells which need to divide more times

Question 9

what type of macromolecule damage also contributes to ageing?

Answer 9

DNA mutation 
breaks 
lipid peroxidation 
protein misfolding 
aggregating 
crosslinking

Question 10

what causes damage to macromolecules?

Answer 10

ionising radiation
reactive oxygen species (diet, radiation, inflammation)
extrinsic toxins (bisphenols)

Question 11

damage to cells causes what 4 main cellular responses?

Answer 11

repair
apoptosis
senescence
malignant transformation

Question 12

what is the disposable soma hypothesis?

Answer 12

once reproduction has occurred, there is little evolutionary value in repairing and maintaining body as genes have been passed on so damage not repaired at same rate it accumulates

Question 13

what is the alternative theory of antagonistic pleiotrophy?

Answer 13

genes have benefit early but have deleterious effects late in life. These genes inherited as benefit early but act as “timebomb” in later life, contributing to cell senescence and death of organism

Question 14

what is frailty?

Answer 14

loss of homeostasis and resilience

increases risk of falls, delirium, disability and death

Question 15

what are the two most common models for operationalising frailty?

Answer 15

deficit accumulation (rockwood)

phenotype (fried score)

Question 16

what are the medical characteristics of old age?

Answer 16

multimorbidity 
multiple medications 
illness can present in atypical ways 
falls, immobility, delirium 
need for rehabilitation