L13: Physiological Aging in Adulthood Flashcards
Ageing
The time-related detoriation of physiological functions
Senescence
The ageing of cells and the organism as a whole. Biological ageing is inevitable
How does ageing manifest at the molecular level?
DNA lesions and the shortening of chromosomes’ telomeres during replication
What proportion of New Zealand’s population will be 65+ by 2050
27%
Define sarcopenia, osteopenia, and dynapenia
Sarcopenia: Loss of muscle
Osteopenia: Loss of bone
Dynapenia: Loss of strength
All are age-related
How much muscle mass is lost every decade after 30?
3 - 8%
What muscle type experiences the most atrophy with age and disuse?
Type 2
Fibrosis
The scarring and thickening of muscle fibres, which makes them thicker, weaker, and more susceptible to injury
If elderly people’s hearts tend to be larger than younger people’s hearts, why are they less healthy?
Elderly people’s hearts are likely to have a greater amount of fibrosis. Even though they appear bigger, they are weaker
Brown adipose tissue
Generates heat. Decreases with age which is why elderly people tend to be colder
White adipose tissue
Involved in lipid storage and immuno-endocrine responses
Why do elderly people tend to have more visceral fat?
Due to changes in gondal hormones
When does bone mass and density begin to decline? How does it differ between males and females?
At 50, espically for females going through menopause due to the drop in estrogen
What are osteoclasts and osteoblasts responisble for?
Osteoclasts: Breaking down old and weak bone
Osteoblast: Building new and strong bone
How does estrogen affect the balence of osteoclasts and osteoblasts?
Estrogen regulates bone metabolism. Lack of estrogen causes the proportion of osteoclasts to be greater than the proportion of osteoblasts
What proportion of myocytes are lost between 30 - 70?
35%
How does the ageing heart compensate for the loss of myocytes?
The heart increases the volume of remaining myocytes, causing hypertrophy but also stiffer walls
Why are elderly people more prone to arrythymias?
Loss of cells in the SA node
What proportion of people over 75 have hypertension?
> 80% for both males and females
What proportion of brain mass if lost every decade after 40? How does this change in older adults?
5% after 40
20% in older adults
What 3 parts of the central nervous system change with age?
- Gret matter
- Neurons
- Synapses
What are 3 effects to behaviour and neurological functioning with age?
- Slower reasoning
- Slower problem solving
- Reduced perceptual speed
Elderly people are still intelligent. They’re just slower
Why do elderly people tend to struggle with memory?
Atrophy with the hippocampus
Why do elderly people struggle with thermoregulation?
Reduced skin blood flow and sweat gland output
