AIIMS MCQ for Medical PG Preparations .. NIME | insipiration the main current of airflow in a normal nasal cavity MCQ

During insipiration the main current of airflow in a normal nasal cavity is through
A. Middle part of the cavity in middle meatus in a parabolic curve
B. Lower part of the cavity in the inferior meatus in a parabolic curve
C. Superior part of the cavity in the superior meatus
D. Through olfactory area

Ans. A.

• During quite respiration inspiratory air current pass through middle part of the nose between the turbinates 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 converts it into eddies under cover of inferior and middle turbinates and this ventilates the sinuses through the Ostia