Age related changes II

Question 1

What are the physiological changes that increase the liklihood of having atrial fibrillation when you are older? [3]

Answer 1

Atrial fibrillation:
* increased fibrosis
* decreased number of pacemaker cells in SA node
* decreased sensitivity to beta-adrenergic receptor stimulation

Question 2

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]

Answer 2

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

Question 3

What happens to ejection fraction with age? [1]

Answer 3

Stays the same

Question 4

What happens to HR with age? [1]

What happens to SV? [1]

Answer 4

HR decreases
SV increases to counteract decreased HR

Question 5

What happens to maximal oxygen consumption with age? [1]

Answer 5

Decreaeses

Question 6

CV system:

What happens to beta-adrenergic and alpha adrenergic reponse with age? [1]

Answer 6

Beta-adrenergic modulation decreases

Alpha-adrenergic response normal

Question 7

What structural differences in the heart occur with ageing between men and women? [2]

Answer 7

Females: concentric hypertrophy - smaller EDV

Males: eccentric hypertrophy - get more dilated cardiomyopathy

Question 8

Why do females get concentric hypertrophy? [1]

Answer 8

menopause causes oestrogen receptors on cardiomyocytes and fibroblasts loss - oestrogen receptors normally prevent hypertrophy

Question 9

Which cardiovascular pathology are men 6x more likely to get than women? [1]

Answer 9

Abdominal aortic aneurysm (AAA)

Screening in men over age of 65

Question 10

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]

Answer 10

Trachea and central airways increase in size leading to:

• More anatomic dead space
• Decreased lung weight

Question 11

Effects of ageing on pulmonary system:

The chest wall thickens. What effects does this have?

Answer 11

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

Question 12

Effects of ageing on pulmonary system:

What happens to maximum exipiratory flow? [1]
What happens to tidal volume? [1]

Answer 12

Maximum expiratory flow: decreases

Tidal volume stays the same

Question 13

Effects of ageing on pulmonary system

What immunological change causes increase in respiratory viruses? [2]

Answer 13

Decreased levels of IgA less able to deal with respiratory viruses

Decreased numbers of neutrophil extracellular traps

Question 14

Effects of ageing on pulmonary system

What physiological changes to the lungs causes respiratory infections more likely? [3]

Answer 14

• Number of cilia and activity of remaining ones reduced
• Glandular cells in large airways reduced
• Decreased nerve endings in larynx - Cough reflex blunted

Question 15

Effects of ageing on the kidneys and renal system:

Describe the changes to the kidney structure [3]

Answer 15

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

Question 16

Why do you have a decreased ability to concentrate urine and clear drugs from body with age? [1]

Answer 16

Decline in number of renal tubular cells and thickening of tubular walls

Question 17

With increased age, what happens to: [3]

• Total GFR
• Nephron number
• Mean single nephron glomerular filtration rate (SNGFR)

Answer 17

• Total GFR decreases
• Nephron number: decreases
• Mean single nephron glomerular filtration rate (SNGFR): increases (to compensate)

Question 18

Describe how overall kidney function remains the same when older, despite total GFR decreasing

Answer 18

Loss of nephrons induces compensatory growth and hyperfunction of remaining nephrons: increases the single nephron glomerular filtration rate (SNGFR) to compensate

Question 19

Conservation of sodium is reduced due to [2]?

Answer 19

Lower plasma renin activity
Urinary aldosterone excretion

Question 20

What happens to the function of mscular ureters, urethra and bladder and why? [2]

Answer 20

Physiological changes:
* Muscular ureters, urethra and bladder lose SMC tone and fibro=collagenous elasticity

Physiological consequences:
* Bladder may retain urine
* Bladder capacity declines

Question 21

Which part of the brain mass declines with age? [1]

Answer 21

Grey matter (neurones)

Question 22

Which part of the brain has particularly bad shrinkage in Alzheimers? [1]

Answer 22

Hippocampus

Question 23

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

Answer 23

• decreased co-ordination [1]
• prolongedreaction time [1]
• impairment of short term memory [1
• decreased sensory conduction time [1]
• more permeableBBB [1]

Question 24

What happens to the shape of the ventricles in the brain in AD? [1]

Answer 24

Become fluid filled and grow larger