kathy
it is a nasal passage. And yes, it makes a circuitous route.Using distilled water and some special saline packet, one can effectivelykeep their nasal cavities opened up so they drain properly and you don;t have to go have sinus cavity surgery like I did a few years back. ALL my cavities need to be opened up. After the surgery I cleaned them all every day using this method that navage uses.
It works. I still do this once a week to keep my breathing passages open naturally...