Restrictive Ventilstory Defect Flashcards
How is compliance calculated?
Volume divided by pressure.
What causes tension in alveolar walls?
Surface tension of alveoli and elastic fibres.
What does surfactant do to surface tension?
Reduced it by increasing compliance, thus reducing the work of breathing.
What is pulmonary fibrosis?
Where elastin fibres are replaced by collagen fibres, causing lung compliance to decrease. Restrictive defect.
What happens in respiratory distress of a premature newborn?
There’s decreased lung compliance due to a deficiency of surfactant.
What happens in emphysema?
Lung compliance increases due to loss of elastin and destruction of alveolar walls. Airway resistance increases. Obstructive defect.
What happens to lung volumes in a restrictive ventilators defect?
All lung volumes are reduced. Minute volume is preserved at start, but also fails as disease progresses.
