Biology of Ageing

Question 1

name the two theories of ageing

Answer 1

‘programmed’ ageing

random damage

Question 2

explain ‘programmed’ ageing

Answer 2

genes to turn on ageing - similar to control of development

Question 3

explain the random damage theory of ageing

Answer 3

accumulation fo 'wear and tear' 
major focus on cell damage
paradoxically essential for life:
oxygen 
cell division 
glucose

Question 4

explain the ‘oxygen’ part in the random damage theory of ageing

Answer 4

ageing is caused by an accumulation of oxidative damage that is not removed or repaired
major reactive oxygen species (ROS) attach to proteins/lipids which then attach to the mitochondria which caused the mitochondria to dysfunction
if this carries on, it eventually damaged the nucleus rendering it useless
less ATP being made

Question 5

explain the ‘cell division’ part in the random damage theory of ageing

Answer 5

cells can only divide a set number of times

when cells are still alive but cannot divide anymore they have reached ‘Hayflicks limit’

Question 6

explain the ‘glucose’ part in the random damage theory of ageing

Answer 6

spontaneous chemical reactions between sugar and proteins: Maillard reaction
advanced glycosylation end: A.G.E products result: protein strands are randomly cross linked making them stiff and irregular

Question 7

name some phycological effects of ageing (hepatic and GI, renal, respiratory and cardiovascular)

Answer 7

hepatic and GI - liver size decreases = reduced capacity
reduce in stomach absorption
renal - renal tubules function less efficiently. enlargement of the prostate gland
respiratory - partial obstruction in inspiration. loss of elastic support around the bronchioles
cardiovascular - pacemaker cells reduce: leads to AF. atrial walls stiffen: raises blood pressure. valves become thicker

Question 8

name some phycological effects of ageing (nervous system, cognition, locomotor, reproduction and senses)

Answer 8

nervous system - lose of vagal tone and reduced sympathetic response. decrease in brain weight and reduce in size due to neurone loss
cognition - mental functions like, attention, memory, recall, orientation
locomotor - loss of skeletal muscle fibres. fat deposited in muscle
reproduction - reproductive organs decrease in size
sense - hearing impairment. blurred vision (presbyopia), cataracts