LC 3.2 - Changes in Structure and Function with Ageing

Question 1

At what age does FEV.1 level peak?

Answer 1

30 years

Question 2

What four effects does ageing have on lung and chest-wall function?

Answer 2

Decreased lung elastic recoil
Decreased respiratory muscle strength
Increased chest wall stiffness
Decreased intervertabral space

Question 3

What three effects does ageing have on lung gas exchange?

Answer 3

Decreased pulmonary capillary volume
Decreased pulmonary artery dispensability
Decreased lung surface area

Question 4

What three effects does ageing have on the lungs ventilatory control?

Answer 4

Decreased responsiveness to hypoxia/hypercapnia
Decreased sensitivity to elastic and resistive loads
Decreased protective airway reflexes (leading to increased disease susceptibility)

Question 5

What is the only organ to enlarge with age?

Answer 5

The heart (left ventricle)

Question 6

Why does systolic blood pressure increase with age?

Answer 6

Larger elastic arteries become thicker and stiffer with age

Question 7

What two effects does ageing have on cardiac function?

Answer 7

Stiffening of main arteries leads to left ventricular hypertrophy
Decreased beta-adrenergic stimulation decreases the hearts efficiency at increasing cardiac output when required (exercise)

Question 8

What effect does ageing have on cardiac ejection fraction?

Answer 8

Ejection fraction does not change

Question 9

What is postural hypo-tension?

Answer 9

Change in position (supine - standing) causes a temporary reduction in blood flow and therefore a shortage of O2 to the brain

Question 10

Why is postural hypo-tension more common in the elderly?

Answer 10

ANS baroreceptors do not function as well with age and therefore the vasoconstriciton reflex which usually counters postural hypo-tension no longer occurs

Question 11

Why is postural hypo-tension more dangerous in the elderly?

Answer 11

Risk of falls and blackouts increases

Risk of fractures and injuries increases

Question 12

Where are baroreceptors located?

Answer 12

In the carotid sinuses

Question 13

What do baroreceptors respond to?

Answer 13

Stretch in blood vessels

Question 14

Define carotid sinus syndrome?

Answer 14

More blood to the head = more stretch detected by baroreceptors, they trigger vasodilation and decreased HR to compensate. In CSS baroreceptors respond to both internal stretch and EXTERNAL factors including shaving and turning of the head

Question 15

What five effects does ageing have on the gastrointestinal system?

Answer 15

Decreased teeth
Decreased taste-buds
Decreased saliva
Decreased HCL production
Decreased gut motility

Question 16

What effect does ageing have on the control of blood glucose?

Answer 16

Insulin works less efficiently to ‘pack away glucose’ via insulin resistance and decreased tissue sensitivity to insulin.
Risk of DIABETES increased

Question 17

What effect does ageing have on osmoregulation?

Answer 17

Decreased sensation of thirst as production of ADH is less effecient, therefore old people have a poorer response to water deprivation.
Risk of DEHYDRATION increased

Question 18

What effect does ageing have on drug handling bioavailability?

Answer 18

Decreased first pass metabolism via decreased liver size and blood flow, therefore more lipid soluble drugs are able to enter the circulation

Question 19

What effect does ageing have on drug handling distribution volumes?

Answer 19

Decreased body water
Increased fat - can lead to the ‘hangover effect’ with sedative drugs as they may be retained in the fat the morning after leading to increased risk of falls

Question 20

What four effects other than bioavailability and distribution does ageing have on drug handling in the body?

Answer 20

Increased passage across blood-brain-barrier
Increased tissue sensitivity
Decreased renal clearance
Decreased hepatic clearance

Question 21

What four effects does ageing have on the immune system?

Answer 21

Decreased number and function of T-helper lymphocytes
Reduced size of thymus gland at 60
Reduced antibody production via B-cells
Decreased IgE production (less allergies)

Question 22

Which latent virus has a 5-fold increased chance of re-activation in patients aged 45-85?

Answer 22

Shingles (re-activation of varicella-zoster-virus)

Question 23

What four effects does ageing have on the renal system?

Answer 23

Decreased renal blood flow
Decreased kidney size
Decreased GFR
Decreased renin and aldosterone levels

Question 24

What is presbyopia?

Answer 24

Difficulty with near vision onset usually post 50 - reading glasses required

Question 25

What is presbyacusis?

Answer 25

loss of high frequency hearing due to degeneration of the cochlear cells

Question 26

What type of memory loss is commonly found through increased age?

Answer 26

Declarative memory loss

Question 27

Why do women have accelerated bone loss?

Answer 27

Menopause