The nostrils are the great gate from the wide atmosphere of heaven to the lungs.

The extreme sigh of yearning we catch through the mouth.

But the delicate nose advances always into the air, our palpable communicator with the infinite air.

Thus it has its first delicate root in the cardiac plexus, the root of its intake.
And the root of the delicate-proud exhalation, rejection, is in the thoracic ganglion.

But the nostrils have their other function of smell.