The conchae divide each nasal cavity into four air channels (Fig. 8.230C,D): an inferior nasal meatus between the inferior concha and the nasal floor, a middle nasal meatus between the inferior and middle concha, a superior nasal meatus between the middle and superior concha, and a spheno-ethmoidal recess between the superior concha and the nasal roof.
These conchae increase the surface area of contact between tissues of the lateral wall and the respired air.