Ageing Flashcards
What are the 2 theories of ageing
- programmed theory
2. error theory
what are the 3 theories that fall under programmed theory
- programmed longevity
- endocrine theory
- immunological theory
define programmed longevity
ageing is the result of genes being switched off over time
define endocrine theory
the biological clock acts through hormones to control rate go ageing
define immunological theory
immune system is programmed to decline over time. Leading to an increase in infectious disease and death
what are the 4 theories that fall under error theory
- wear and tear theory
- cross linking theory
- free radical theory
- somatic DNA damage theory
define wear and tear theory
cells and tissues wear out from repeated use
define cross linking theory
accumulation of cross linked proteins damage cells and proteins
define free radical theory
free radicals cause damage to macromolecular components of cells - which causes accumulative damage, impaired function and cell ageing
define somatic DNA damage theory
accumulation of DNA damage to cells causing ageing. Talameres shorten with each division of cells
define primary ageing
changes that we expect, even if remaining healthy
define secondary ageing
the degenerative diseases which become more common with age
what happens to blood supply in the nervous system as a result of ageing
blood supply decreases which is associated with a decline in brain mass
list the age related changes of the lens
- thickens
- yellows (calls for an increase in light to stimulate receptors)
- clouds
- less elastic
(also the cornea thickens and pupil size declines)
what are the 2 conditions that affect accomodation
- presbyopia
2. hyperbola
define presbyopia
hyperbola caused by a decline in elasticity of the lens
define hyperbola
being unable to focus pictures on the back of the eye
what is a cataract
clouding of the lens that disperses light entering the eye
what are the 2 categories of hearing loss
- conductive
2. sensory neural (cochlea or nerve damage)
list some of the changes to hearing that occur due to ageing
- decline in elasticity of the tympanic membrane
- impaired articulation of the ossicles
- loss of neurones in the auditory cortex
- accumulation of noise damage
- high pitch more difficult to hear
list some of the changes to balance that occur due to ageing
- loss of hair cells
- degeneration of otiliths (?decline in proprioception) \
what are the 3 physical characteristics of the cardiovascular system,
- distensibility
- contractility
- elasticity
what are the 3 clinical functions
- blood pressure
- cardiac output
- heart rate
how is blood pressure affected as a result of ageing
blood pressure is influenced by peripheral resistance.
Peripheral resistance > with age = > BP
what are the 3 factors that determine cardiac output
- contractility
- end diastolic volume
- heart rate
list the change that occurs to End Diastolic Volume as a result of ageing
An increase in age leads to a < in diastolic filling due to L ventricle stiffness which can lead to atrial fibrillation and ultimately heart failure
what change occurs with heart rate as a result of ageing
a decline in HR in response to exercise, secondary to a decline in response to adrenaline/noradrenaline
how is the baroreceptor function and postural hypertension affected as a result of ageing
- baroreceptor reflex declines with age
- a decline in this reflex can lead to postural hypotension and fainting
list some of the changes to the respiratory system as a result of ageing
- loss of elastic lung recoil due to damage to fibres in alveolar walls
- thinning and disruption of alveolar walls = < alveolar surface
- rib cartilage becomes calcified = more muscle effort required
what imbalances can a decline in globular filtration lead to (renal system)
- electrolyte imbalance
- acid base balance
- reduced creating clearance
- reduced clearance of toxins
what can lead to an incline in incontinence (renal system)
- decline in elasticity and volume of bladder
- loss of sphincter tone
- poor control
list some changes of the gastrointestinal tract due to ageing
- decline in food intake
- decline in calorific requirement
- decline in senses
- decline in peristalsis = constipation
define sarcopenia
muscle atrophy and decline in mass
list causes of sarcopenia
< exercise < hormone levels < motor neurons < fibres = > fat < effectiveness of mitochondria
how can sarcopenia be prevented
- continuing activity
- weight lifting as it encourages osteoblasts to deposit calcium
list some changes to the skin due to ageing
- < contact between epidermis and dermis results in easy separation by simple trauma
- < melanocytes = grey hair
- < sweat glands = > heat stroke
