The Compendium of Bheḷa 1.6.39

1.6.39

varcaḥkarmoddhato vāyurgalamūrdhaśirogataḥ | prāṇānādhmāpayati vā sa dhūmenānulomyate ||

Wind raised up by the act of defecation, gone to the throat, top of the head, or cranium, / or blowing up the vital breaths, is moved downward normally by smoke.