Week 2 Flashcards
(30 cards)
What is the immunological theory
Aging is controlled by the immune system
Aging is a mild, prolonged, auto-immune disorder
Inflammation can lead to cell death
Explain how the prevalence of Chronic Disease Increases with age
after our 40s-50s, chronic disease risk increases because of a decrease in our immune system
What are major events in the immune system that happen as we age? (NON-Specific/general response to pathogen)
- skin cells deteriorate (therefore weakened barriers, easier for pathogens to enter)
- phagocyte dysfunction (protein concentration decreases, fewer overall)
What are major evens in the immune system that happens as we age? (Specific to certain pathogens)
- bone marrow decreases; b-cell production decreases
- thymus mass decreases; t-cells decrease
What are b-cells? Do they divide through life?
B-cells are made in the bone marrow and attack pathogens outside the cells.
They do divide throughout life
What are t-cells? Do they divide throughout life?
T-cells are made in the thymus
They attack infected cells inside muscle cells
They do divide throughout life
What are phagocytes? Do they divide throughout life?
Phagocytes are the first line of defence if a pathogen gets passed the skin barrier
It does NOT divide throughout life
How can we prevent the decline in the immune system?
Exercise and nutrition
Reduce inflammation
Anti-inflammatories
Explain the flowchart of aging and the immune system
decreased barrier, phagocyte function, b-cells and t-cells - decreased immune system functioning - results in increased inflammation (low levels, starts negative cycle of immune system functioning)
ROS increase - contributes to elevated inflammation
What are other contributing factors in promoting chronic inflammation?
age-related frailty
cancer
cvd
ocular disease
autoimmune disease
pulmonary disease
neurodegenerative disease
periodontitis
metabolic syndrome
Describe the difference between programmed longevity theory and the immunological theory of aging
Programmed Longevity = biological clock, telomeres shorten and cells die
Immunological Theory = cells die as a result of inflammation
What is not subject to hayflicks limit, but is susceptible to the biological clock?
b cells
phagocytes
skin barrier
What is the endocrine theory?
Changes in endocrine control of homeostasis results in age-related changes in physiology
What is the hypothalamus?
Connects the NS system with the endocrine system through the pituitary gland
It stimulates or inhibits functions to maintain homeostasis
What happens to the hypothalamus as we age?
The number of cells in the hypothalamus decreases and therefore decreases hormone production
Also an increase in calcification (results in non-functional tissue), more calcium means organs are less able to function
The endocrine is responsible for maintaining homeostasis in……
metabolism
growth and development
sexual function and reproduction
heart rate
blood pressure
appetite
sleeping and waking cycles
body temp
The endocrine is responsible for maintaining homeostasis in……
metabolism
growth and development
sexual function and reproduction
heart rate
blood pressure
appetite
sleeping and waking cycles
body temp
How could you test the importance of hypothalamus cell numbers on aging?
most ideal: tracking the same individual over time and looking at the changes in their hormone levels
most direct way: increasing/decreasing the number of cells and evaluating the effects
What happens when we increase hypothalamus cells vs when we decrease hypothalamus cells in mice
increase cells: we have enough already, increasing does not give benefits in performance
decreasing cells: substantial declines in mice, has an affect on physical, cognitive and social contexts
What is the similarity between the endocrine and immunological theories of aging?
- all lead to a reduction in cells
- all involve damage to cells that result in a loss of functioning
- endo not functioning; things being our of homeostasis , increased inflammation, immune system declines
Describe the relationship between the programmed longevity theory, immunological theory and the endocrine theory of aging
– all lead to a reduction in cells
- all involve damage to cells that result in a loss of functioning
- endo not functioning; things being our of homeostasis, increased inflammation, immune system declines
- biological clocks involved in all 3; reduction in hypo cells not subject to hayflicks limit
What is the wear and tear theory?
- progressive damage to cells and tissue due to use over time
- vital parts “wear out”
- e.g., free radical theory (damage to tissue due to disuse over time)
What are free radicals?
- atoms with an uneven number of electrons
- the unpaired electron makes them unstable (looking for something to bind to)
- easily reacts with healthy atoms
What are reactive oxygen species?
Free radicals that contain oxygen
