Age related changes II Flashcards
What are the physiological changes that increase the liklihood of having atrial fibrillation when you are older? [3]
Atrial fibrillation:
* increased fibrosis
* decreased number of pacemaker cells in SA node
* decreased sensitivity to beta-adrenergic receptor stimulation
Describe the physiological changes to your heart as you age [2]
What happens to diastolic filling rate & why? [2]
What happens to systolic BP? [1]
Heart:
* Size stays the same
* Heart wall thickens with age
Diastolic filling rate:
* decreases with atrial contribution to ventricular filling normal
Systolic BP at rest:
* increases with end systolic volume and ejection fraction not significantly altered
What happens to ejection fraction with age? [1]
Stays the same
What happens to HR with age? [1]
What happens to SV? [1]
HR decreases
SV increases to counteract decreased HR
What happens to maximal oxygen consumption with age? [1]
Decreaeses
CV system:
What happens to beta-adrenergic and alpha adrenergic reponse with age? [1]
Beta-adrenergic modulation decreases
Alpha-adrenergic response normal
What structural differences in the heart occur with ageing between men and women? [2]
Females: concentric hypertrophy - smaller EDV
Males: eccentric hypertrophy - get more dilated cardiomyopathy
Why do females get concentric hypertrophy? [1]
menopause causes oestrogen receptors on cardiomyocytes and fibroblasts loss - oestrogen receptors normally prevent hypertrophy
Which cardiovascular pathology are men 6x more likely to get than women? [1]
Abdominal aortic aneurysm (AAA)
Screening in men over age of 65
Effects of ageing on pulmonary system:
What happens to the size of trachea and central airways? [1]
What is the physiological effect of this? [2]
Trachea and central airways increase in size leading to:
- More anatomic dead space
- Decreased lung weight
Effects of ageing on pulmonary system:
The chest wall thickens. What effects does this have?
Loss of elastic recoil in the lung: inspire to the same level but the lung doesn’t recoil to the same level: leads to senile hyperinflation
Effects of ageing on pulmonary system:
What happens to maximum exipiratory flow? [1]
What happens to tidal volume? [1]
Maximum expiratory flow: decreases
Tidal volume stays the same
Effects of ageing on pulmonary system
What immunological change causes increase in respiratory viruses? [2]
Decreased levels of IgA less able to deal with respiratory viruses
Decreased numbers of neutrophil extracellular traps
Effects of ageing on pulmonary system
What physiological changes to the lungs causes respiratory infections more likely? [3]
- Number of cilia and activity of remaining ones reduced
- Glandular cells in large airways reduced
- Decreased nerve endings in larynx - Cough reflex blunted
Effects of ageing on the kidneys and renal system:
Describe the changes to the kidney structure [3]
Kidney size decreases:
-
number of glomeruli decreases
THIS LEADS TO A - A loss of renal tubules, as they are not needed if no glomeruli
- Decline in number of renal tubular cells and thickening of tubular walls
Why do you have a decreased ability to concentrate urine and clear drugs from body with age? [1]
Decline in number of renal tubular cells and thickening of tubular walls
With increased age, what happens to: [3]
- Total GFR
- Nephron number
- Mean single nephron glomerular filtration rate (SNGFR)
- Total GFR decreases
- Nephron number: decreases
- Mean single nephron glomerular filtration rate (SNGFR): increases (to compensate)
Describe how overall kidney function remains the same when older, despite total GFR decreasing
Loss of nephrons induces compensatory growth and hyperfunction of remaining nephrons: increases the single nephron glomerular filtration rate (SNGFR) to compensate
Conservation of sodium is reduced due to [2]?
Lower plasma renin activity
Urinary aldosterone excretion
What happens to the function of mscular ureters, urethra and bladder and why? [2]
Physiological changes:
* Muscular ureters, urethra and bladder lose SMC tone and fibro=collagenous elasticity
Physiological consequences:
* Bladder may retain urine
* Bladder capacity declines
Which part of the brain mass declines with age? [1]
Grey matter (neurones)
Which part of the brain has particularly bad shrinkage in Alzheimers? [1]
Hippocampus
Brain mass and cerebreal blood flow in the brain causes what biological consequences for:
- co-ordination [1]
- reaction time [1]
- short term memory [1
- sensory conduction time [1]
- BBB
- decreased co-ordination [1]
- prolongedreaction time [1]
- impairment of short term memory [1
- decreased sensory conduction time [1]
- more permeableBBB [1]
What happens to the shape of the ventricles in the brain in AD? [1]
Become fluid filled and grow larger
