inside the heart - Tissue-paper thin but tough, the valves of the human heart open and close to pump 6 quarts of blood a day through miles kilometers) of vessels. That’s equivalent to 20 treks across the United States from coast to coast.
Svatmarama, Hatha Yoga Pradipika ~ When the breath wanders the mind also is unsteady. But when the breath is calmed the mind too will be still, and the yogi achieves long life. Therefore, one should learn to control the breath.