Airway resistance = Flow Resistance - pick the wrong statement
Laminar flow in the acinus - low velocity and Reynolds number is low
Trachea-bronchi - turbulent flow - high velocity and high Reynolds number
decrease in the radii of the bronchioles in half, which increases their resistance by 4-fold
Airway resistance is the highest in the 3rd to 5th generation bronchi
Effects of lung volume on airway diameter
Airway resistance decreases as lung volume increases during inspiration and vice versa during expiration
Airways are elastic so they increase diameter when Pleural pressure goes up
This is why it takes longer to exhale during passive breathing than to inhale
all of the above are correct
Lung volume and airflow
Inspiration is effort dependent
During expiration increase in effort produces increases in flow only during the initial quarter of the expiratory vital capacity
During expiration at low and moderate lung volumes - flow is maximal and is effort independent
At Equal Pressure Point
When the pressure in airway is equal to pleural pressure Paw = Ppl
During Forced expiration - Upstream of EPP (toward alveoli) driving pressure, PA-P mouth - will move air out of the lungs
During Forced expiration - Downstream of EPP (toward mouth) PA -Ppl
Patients with emphysema have lungs that are easy to inflate, but they don't generate enough elastic recoil pressure to get the air out which causes airways collapse and air trapping
