Unformatted text preview: Inspiratory capacity (1C) - approximately 75 % of vital capacity (VC)
Total lung capacity = vital capacity plus residual volume In maximal aerobic exercise, breathing frequency can increase up to 60
breaths per minute and tidal volume can increase up to 50% of vital
capacity. Alveolar ventilation(V A) - the volume of air that reaches the alveoli per minute. This value is very important because this is the only air that
participates in gas exchange with the blood. VA=(VTXFR)-(VDXFR)
= 500le 12 -150le12
= 6000 ml - 1800 ml
= 4200 ml/min. Most volumes and capacities decrease when a person lies down and increase when standing. Reasons: 1. Abdominal contents push up against diaphragm 2. There is an increase in intrapulmonary blood volume in the horizontal
position which decreases the space available for pulmonary air. IV. Pulmonary Disorders Pulmonary function test norms are usually based on sex, age, and height.
It is important to know the size and make-up of the population used to
construct the norms. Problems with pulmonary function norms:
- don’t consider the “size” of the subject, particularly the chest size
- would be better to use sitting height rather than standing height Chronic pulmonary dysfunctions can be divided into two categories: 1. Obstructive disorders - blockage or narrowing of the airways causing
increased airway resistance - asthma, bronchitis, emphysema. ...
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- Spring '09