During insipiration the main current of airflow in a normal nasal cavity is through

* During quite respiration inspiratory air current pass through middle pa of the nose between the turbinatcs and nasal septum. * Very little air passes through inferior meatus or olfactory region of the nose. * Therefore weak odorous substances have to be sniffed before they reach olfactory area. * During expiration air current follows the same course as during inspiration but the entire air current is not expelled directly through the nares. * Friction offered at lumen nasi conves it into eddies under cover of inferior and middle turbinates and this ventilates the sinuses through the Ostia