Small airways have laminar air flow because:: (A) Reynold's number > 2000, (B) Very small diameter, (C) Extremely low velocity, (D) Low cross sectional area
Answer is C. Small airway have low reynold number, large cross sectional area, large diameter and air flows at a very low velocity. Ref: Physiology of respiration By Michael P. Hlastala, Albe J. Berger, Page 52; Review of Medical Physiology by William ganong, 22nd edn/page 583