Ageing

Ageing

1. Sarcopenia

   • Metabolic changes in sarcopenia
     • FR mitochonrial damage
     • Decrease PS
     • altered metabolism
   • cellular changes in sarcopenia
     • Atrophy
     • sarcomere disorganisation
     • denervation
   • general facts
     • 3-8% muscle loss per decade
     • makes more likely to fall
     • decreased PS (Test, IGF, GH)
   • 30-60 years = increase in body fat but > 60 years = decline in body mass

2. Ageing and genetics

   • Chromosome replication failures
     • Telomere shortening
       • Defective Werners protein is conditions that kills you before 50 - acerbated telomere shortening
   • DNA redundancy failures
     • Loss of redundant sequences
   • Progeria - LMNA gene defect

3. Causes of ageing

   • Free radicals
     • Formed when covalent bond splits and unpaired electron left on molecule - Fe3+ + H202 ---> :OH- + Fe2+ + H20.
       • MALONDIALDEHYDE attacked by FR which destabilises membrane
     • Vitamin C & E trap FR once membrane bound
   • Apoptosis

4. CVS changes

   • Poor blood flow
     • Sympathics attack on blood vessels
   • Heart problems
     • Desensitised adrenergic receptors by catecholoamines
     • Inceased collagen so stiffer muscle
     • Necrosis and apoptosis of tissue over time
   • Vessel problems
     • Arteries become stiffer as more collagen
     • Thickening of intimata in veins

5. Ageing and special senses

   • Vision
     • Presbyopia - stiff and thicker sense cannot convex.
     • Cataracts = deterioration of sense so it becomes opaques
   • Hearing
     • Presbycusis - Universal deterioration of hearing starting with high frequencies

6. Thermoregulation

   • Cannot regulated body temperature properly
   • Decreased muscle mass
   • reduced efficiency of effector responses
   • atrophy of sweat glands
   • thinner skin

7. Osteroporosis

   • Porous bones due to clack of calium
   • More common in women
   • prevention = 1000mg of supplement per day

8. Growth and development terminated by death

9. Scenescence - post repoductive decline in viability acommpanied by age