Streamlining of air flow in the upper airways and trachea.

Streamlining of air flow in the upper airways and trachea has been investigated by inhaling 81m krypton through each side of the nose separately and counting over the lung fields with a gamma camera. 81m Kr inhaled through one nostril was uniformly mixed in the air stream by the time the carina was reached. Gas mixing occurs probably by a combination of diffusion and turbulent flow.