L29 Respiratory Responses to Exercise Flashcards
Define Inspiratory reserve Volume
the maximal amount of additional (above tidal volume) air that can be drawn into the lungs
Define Tidal Volume
the amount of ait which enters the mungs during a normal breath in at rest
Define Expiratory reserve volume
the amount of extra air exhaled above tidal volume during a forceful breath out
Define Residual Volume
the amount of air left in the lungs after maximal exhalation
Define inspiratory capacity
tidal volume + inspiratory reserve volume
The most you can physically breathe in
Define functional residual capacity
the amount of air left in your lungs after a normal breath out (vital capacity)
Define vital capacity
the most air you can exhale after taking the deepest breath you can
Define forced vital capacity
The amount of air which can be forcibly exhaled after taking the deepest breath in as possible
Define maximal voluntary ventilation
the point you reach after a maximal exhalation - when only the residual volume is left
Explain the non-linear increase in ventilation at higher exercise intensity
IRV and ERV decrease during exercise as TV increases
Describe how ventilation increases in exercise
As ventilation increases it becomes increasingly costly in terms of O2 uptake
As you breathe more, your ventilatory muscles use more of the O2 inspired, therefore less o2 to your working muscles. Minute ventilation dramatically increases during exercise - despite a huge minute ventilation, tidal volume rarely exceeds 60% of VC.
During exercise both rate and depth increase. Initially larger increases in depth occur so that tidal volume increases, this is then followed in increased in rate and depth
This ventilatory relationship as submax does not continue above the breakpoint
Explain why arterial hypoxaemia may occur in some athletes
Arterial hypoxaemia = lower than normal O2 content in arterial blood
Problem = reduced max oxygen uptake
Cause? = dead space, ventilation/perfusion ratios. Mean transit time too short to allow full O2 saturation
Discuss whether ventilation is a limiting factor for maximal oxygen uptake
no, Maximum Voluntary Ventilation averages 25% more than what it would be in VO2 max
- @ steady state exercise additional anaerobic exercise raises ventilation
- Subjects can voluntarily raise their ventilation while exercising @ maximum workload
Describe how the oxygen cost of breathing during exercise differs in men and women
- Women have smaller lung function measures than men
- Highly fit women must work harder to maintain adequate alveolar-to-arterial O2 exchange
