Your Nostrils Are Amazing
How those two holes in the middle of your face share smelling duties
I’m trying to think about simple things right now: things that I might have overlooked when I cared whether my Metrocard was full; things to distract me from the feeling of despair that hangs in the air; things that are right in front of me, or even, on me, that I may have taken for granted 11 months ago. Like my nose.
When we’re not hyperventilating about the state of our country, we take around 22,000 breaths a day. And, unless you’re a mouth breather, we also inhale smells. But did you know that our nostrils are engaging in a pas de deux all day long, taking in different but complementary odors and air flows? Thinking about how they collaborate to form a cohesive and functioning nose will blow your mind every time you blow your nose.
Your right and left nostrils perceive odor differently. In a recent interview for NPR’s TED Radio Hour, we talked to art and scent historian Caro Verbeek, who told me that, as we breathe, “There’s a constant fast airflow in one of your nostrils and a slow one in the other.” Some odorous molecules are only detectable in air flows; others in fast air flows. “So in order to perceive everything, you have to use both nostrils to smell three-dimensionally.” I tested this out on my coffee. First, I smelled with just my right nostril; then my left. It was like an episode of Song Exploder for my nose: I heard a melody in one nostril and harmony in the other. One whiff was like smelling the higher notes of fruit; the other had earthy undertones. When I brought the two smells together with one big inhale, it was like combining two music tracks into a full song.
You can lose your sense of smell. And get it back. We’ve been hearing for nearly a year now that one of the first symptoms of Covid-19 is loss of smell. But Covid sufferers who have “persistent anosmia” may find their sense of smell returns years from now. In a great Buzzfeed article this month, writer Jessica Garrison explains how she lost her ability to smell after sinus surgery 20 years ago. Some people still don’t believe her when she says she can’t smell, say, a really stinky piece of cheese. She also reports that, “While doctors are hopeful many will recover this sense, it could take months to years, because the neurons in your nose have to replace themselves, and then they have to grow new axons that extend up and connect to the brain. And this takes time.”
Your nostrils take turns being dominant every three hours. Or, as this 2016 paper on “Measuring and Characterizing the Human Nasal Cycle” explains, “Nasal airflow is greater in one nostril than in the other, and the greater airflow nostril shifts between left and right over time.” These researchers posit that the change in airflow “optimizes each nostril for different odors.” Other scientists think this happens so neither nostril gets dried out, or to protect against allergies and other invaders. But no one nose for sure.