16. McArdle ch. 12 Flashcards
what is tidal volume? (Vt)
volume of air inspired or expired with each normal breath.
what is inspiratory reserve volume(IRV)?
extra volume of air that can be forcefully inspired over and above VT.
what is expiratory reserve volume(ERV)?
maximum extra volume of air that can be forcefully expired over and above VT.
what is residual volume(RV)?
volume of air remaining in lungs after forceful expiration.
what does residual lung volume allow for?
Allows an uninterrupted exchange of gas between the blood and alveoli, which prevents fluctuations in blood gases during phases of the breathing cycle
how does residual lung volume increase temporarily?
increases from an acute bout of either short-term or prolonged exercise due to:
- Closure of the small peripheral airways
- Increase in thoracic blood volume
what are the 4 pulmonary capacities?
- inspiration capacity(IC)
- functional residual capacity(FRC)
- forced vital capacity(FVC)?
- total lung capacity(TLC)
what is inspiration capacity(IC)?
maximum amount of air that can be inspired from end of normal expiration (= VT + IRV).
what is functional residual capacity(FRC)?
amount of air remaining in lungs after normal expiration (= ERV + RV).
what is forced vital capacity(FVC)?
maximum amount of air that can be forcefully inspired and expired (= IRV + VT+ ERV).
what is total lung capacity(TLC)?
maximum amount of air comprised in the lungs (= IRV + VT + ERV + RV).
what doe dynamic ventilation depend on?
-Maximum “stroke volume” of the lungs (FVC)
-Speed of moving a volume of air (breathing rate):
which is Determined by lung compliance, or the resistance of the respiratory passages to air and the “stiffness” imposed by the chest and lung
what does max voluntary ventilation evaluate?
-Evaluates ventilatory capacity with rapid and deep breathing for 15 seconds
:Extrapolated to the volume if the subject continued for 1 minute
what is the gender difference in lung measures?
women have a reduced lung size and airway diameter, a smaller diffusion surface and static and dynamic lung function measures
what does a smaller lung size lead to in women?
This leads to expiratory flow limitations, greater respiratory muscle work and use of ventilatory reserve during maximal exercise, particularly in highly trained women
Does regular endurance exercise stimulate large increases in the functional capacity of the pulmonary system?
Regular endurance exercise does not stimulate large increases in the functional capacity of the pulmonary system
Dynamic lung function tests indicate the severity of obstructive and restrictive lung diseases, but provide _____ information about aerobic fitness or exercise performance when values fall within the normal range
little info
how can minute ventilation be increased?
by an increase in the rate or depth of breathing, or both
In moderate exercise, well-trained athletes maintain alveolar ventilation by increasing ____ with only a small increase in breathing rate
tidal volume
true or false? Attempts to modify breathing during running or other general physical activities offer no benefit to exercise performance
true
what is the ventilation/perfusion ratio?
the ratio of alveolar ventilation to pulmonary blood flow
avg=0.84 ratio
what is anatomical dead space?
anatomical structures of the respiratory system that are not directly involved in gas exchange, generally ranges between 150-200 mL
what is physiological dead space
The portion of the alveolar volume with a ventilation–perfusion ratio that approaches zero:
the alveoli may not function adequately in gas exchange because of:
-Underperfusion of blood
-Inadequate ventilation relative to the alveolar surface
In certain pathologic situations, physiologic dead space increases to ___% of the tidal volume
50%
