Shiva Purana
अवाङ्नयत्यपानाख्यो यदाहारादि भुज्यते ॥ व्यानो व्यानशयत्यंगान्यशेषाणि विवर्धयन् ॥ ३७ ॥
Apāna is the vital air that takes the food lower down. Vyāna is diffused through the limbs and it develops them.
english translation
avAGnayatyapAnAkhyo yadAhArAdi bhujyate ॥ vyAno vyAnazayatyaMgAnyazeSANi vivardhayan ॥ 37 ॥
hk transliteration by Sanscript