Nostrils
Apparently, the right nostril constricts when your nervous system needs to calm down. I always wondered why my right nostril would close off at night when I was trying to fall asleep. I either had to sleep on my left side, use Vick's Sinex Severe every day, and I had a surgery on my nose to reduce the size of my turbinates. Nothing worked.
Now, somehow, I'm breathing much easier. I wonder if it's because I've been working for so long on creating a healthy nervous system, or maybe the desert environment agrees with me? I'm not sure, but I know that I no longer have to take a spray for my nose, and I'm no longer anxious about not being able to sleep at night.
I appreciated learning about how nostrils alternate in size to help calm our minds. Without that knowledge, I would not trust that my body was working correctly. I'm starting to think of working with my body rather than my body working against me.