what happens to interpleural pressure from the top of the lungs to the base of the lung?
intrapleural pressure becomes less negative and more positive
why does the interpleural pressure gradient happen?
because gravity pulls lung tissue downward and the weight compresses the lower pleural space which makes the interpleural pressure less negative at the base.
what does transpulmonary pressure determine?
how open the alveoli are at rest.
- higher tp = larger resting alveoli
- Lower tp = smaller resting alveoli
what does it mean dependent region?
the part of the lungs most influenced by gravity
what does it mean non dependent region?
the part of the lungs not influenced by gravity
what is the steps in radioactive xenon method for measuring regional ventilation and perfusion
- pt. inhales radioactive xenon-oxygen mixture.
- xenon is insoluble and stays in the lungs to map ventilation
- radiation detects top, middle, and bottom of lungs distribution
what is closing capacity?
the lung volume when airway closure begins
what closing volume?
closing capacity - residual
