Week 12 Flashcards
With ageing, the number of alveoli and corresponding capillaries _____
decrease
With ageing there is an _____ in size of surviving alveoli
increase
With ageing, elastic properties comprised due to changes in collagen (which ______) and elastin (which _____)
increases, decreases
With ageing, bronchioles _____ which increases ______ to airflow
narrowing, resistance
With age, Increased ______ of peripheral airways which can reduce expiratory flow rates
collapsibility
With age, there is a ______ of larger pulmonary arteries
thickening
Residual volume—>
amount of air in lungs after forced exhalation
Functional residual capacity —>
volume of air in lungs after a passive exhalation
Compliance of chest wall _____ with ageing
decreases
Lung elastic recoil _____ with ageing (i.e. increase in compliance)
decreases
Calcifications of the costal cartilages and chondrosternal junctions, and degenerative joint disease of dorsal spine contribute to …?
Chest wall stiffening
Structural changes of chest wall and lung elastic recoil lead to:
- static air trapping (increased residual volume)
- Increased functional residual capacity
- Increased work of breathing
Residual volume can increase by as much as ___%
30%-50%
By age 70, vital capacity may decrease by as much as ____%
40-50%
Intercostal muscle mass and force are _____ with ageing. __ _____ in diaphragm thickness but a decrease in the curvature and this its force-generating capacity
reduced, no change
Possible reasons for decline in respiratory muscle function:
- Changes in shape of rib cage
- Nutritional status
- cardiac function
- sarcopenia
Ability to perform spirometry to test pulmonary function can be comprised by reduced cognitive function, such as with dementia. This can lead to…??
underdiagnosis and undertreatment of chronic obstructive pulmonary disease in older people
- Measurement of airway resistance using the forced oscillation technique (FOT) is an alternative for assessing COPD in older patients with cognitive disorders
Total lung capacity increase/decreases/remains constant with ageing
remains fairly constant
The increase in residual volume with ageing means there is a progressive ____ in vital capacity to approx 75% with ageing
decrease
flow volume curves and peak expiratory flow with ageing….?
- Reduced peak expiratory flow in older individuals
- Changes in expiratory flow volume curve with ageing suggest obstruction to airflow
- Likely due to changes in small peripheral airways and loss of supporting tissue
The ageing respiratory system is associated with:
- decreased cough reflexes
- an increased likelihood of sleep apnoea
- Increased susceptibility to pulmonary inflammation
Decreased cough reflexes are due to…?
- less forceful and productive in swallowing and cough reflexes in ageing
- This lack of sensitivity may change at level of bronchioles, nerves or brain
- Airway clearance less effective due to less strength in muscle
An increased likelihood of sleep apnoea is due to…?
- % of time in REM is less, light sleep more frequent, circadian rhythms are weaker
- melatonin decreased
- Defective chemical feedback control has been suggested to contribute
- Some evidence suggests that ventilatory drive to the pharyngeal muscles is reduced, leading to narrowing of the airways
The Increased susceptibility to pulmonary inflammation is due to….?
- weaker immune system
- reductions in ciliary motility and mucous cel production
Ageing is associated with reduced alveolar surface area, fewer pulmonary capillaries and mismatches between _____ and ____.
ventilation and perfusion
High ventilation, low perfusion =
wasted ventilation/physiologic dead space
Low ventilation, high perfusion =
wasted perfusion of blood/’venous admixture’/’physiological shunt’
How do the elderly compensate for altered compliance and gas exchange?
By breathing more rapidly at lower tidal volume to maintain alveolar ventilation
- Greater ventilatory response to CO2 during exercise to compensate for greater dead space
- During hypercapnea the CO2 threshold for increased inspiratory effort is reduced
VO2 max generally ____ with age
declines
What factors affect decline in vo2max most?
Circulatory factors (decreased max HR, muscle mass) > pulmonary factors
The expiratory flow limitation and concomitant increase in expiratory resistance (flow resistive work) in the older subject cause the ventilatory work to ___ curvilinearly with exercise.
increase
Compliance of chest wall and lung elastic recoil decrease with age, resulting in static air trapping (increased residual volume), _____ functional residual capacity, and ____ work of breathing
increased
Reduced alveolar surface area and greater mismatching of ventilation and perfusion may jeopardise ___ _____, although mechanisms exist to compensate for this.
gas exchange
Older people tend to breathe at higher lung volume–> inspire the same volume but it is closer to total lung capacity because their residual volume is _____
greater
What increases with ageing during adulthood?
Residual volume
Which of the following changes to the respiratory system does NOT typically occur with ageing during adulthood?
- A reduction in size of alveoli
- A decrease in the compliance of the chest wall
- Reduced elastic recoil
- A decline in respiratory muscle strength
A reduction in size of alveoli (FALSE)
- decrease number, not size
