Effects of ageing on NS Flashcards
what is Alzeimers
form of dementia
reduced cognitive ability associated with gradual death of brain cells
Familial onset
-inherited
-some alleles cause early onset
what are the alleles that tend to AD mutations
amyloid precursor protein
presenilin 1 & 2
what causes sporadic AD
Most are this
Other genetic differences
Repeated head injury
Stroke
Low levels of intellectual stimulants
what causes vascular dementia
High BP
Smoking
High blood cholesterol
-cognitive impairment occurs due to reduced blood flow to brain
symptoms of AD in MRI
Reduction in size of different brain regions
Symptoms of AD
Progressive memory loss
Plagues: deposits of B amyloid between neurones
Tangles: Tau tangles within neurones
Cells in region of plages & tangles: secrete less Ach
what are Tau proteins
Proteins that stabilise microtubules
How do Tau protein contribute to development of AD
Build-up in the cytosol
Accumulation of tangles
Microtubules disintegrate
Disrupts neurone transport system
Disrupts biochemical communication eg. vesicles can’t fuse with pre-s membrane
Plaque formation for AD
B amyloid
Fewer & shorter dendrites
Treatments to help with AD
Drugs that inhibit acetylcholinesterase- slow down rate of decline of Ach
Vaccines tested in mice which breaks down plaques:
-antigen abnormal part of AB
-antibodies bind to AB
-removed by phagocytes
how can memory loss be reduced
frequent exercise
social interaction
good diet
managing stress
intellectual stimulus eg learning language
what is presbycusis
age related hearing loss. Affects high frequencies
Causes presbycusis
sensitive hairs in cochlea damaged & die
neurones in auditory nerve damaged & die
what is age-related macular degeneration (ARMD)
a severe reduction in vision that cannot be corrected with glasses or contact lenses and reduces a persons ability to function at tasks
Major effect on lifestyle e.g. reading, recognising faces
dry ARMD
cellular debris accumulates between retina & choroid and causes retina to become detached
wet ARMD
Abnormal growth of blood vessels in the choroid
which leak of fluid onto retina
scarring of the macular
retina can detach
how is wet AMRD treated
laser coagulation
what is cataracts
a loss of transparency of lens, resulting in cloudy vision
factors that contribute to cataract development
age
smoking
alcoholism
diabetes
how to treat cataracts
removing the cloudy lens and replacing it with a clear plastic one during surgery
what is glaucoma
damage of the optic nerve due to increased pressure and a lack of drainage
chronic open glaucoma
blocked drainage channels
aqueous humour cannot drain away
increase intraocular pressure
primary angle closure glaucoma
edge of iris and cornea come in contact with each other
pressure rises suddenly as aqueous fluid cannot reach drainage channels
