This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
During insipiration the main current of airflow in a normal nasal cavity is through 
Select and explain. 
A. Middle pa of the cavity in middle meatus in a parabolic curve, B. Lower pa of the cavity in the inferior meatus in a parabolic curve, C. Superior pa of the cavity in the superior meatus, D. Through olfactory area
A: Middle pa of the cavity in middle meatus in a parabolic curve
Answer: A: Middle pa of the cavity in middle meatus in a parabolic curve 
Explanation: * 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