अथ यदा सुषुप्तो भवति यदा न क-स्यचन वेद हिता नाम नाड्यो द्वासप्त-तिः सहस्राणि हृदयात्पुरीततमभिप्रति-ष्ठन्ते ताभिः प्रत्यवसृप्य पुरीतति शेतेस यथा कुमारो वा महाराजो वा महा-ब्राह्मणो वातिघ्नीमानन्दस्य गत्वा श-यीतैवमेवैष एतच्छेते ॥ १९ ॥
In plain words
Now, when a person falls into deep, dreamless sleep — when he is aware of nothing at all — seventy-two thousand fine channels called the 'hita' veins run from the heart out to the pericardium. Through them he slips quietly down and comes to rest there, in the pericardium. And just as a young prince, or a great king, or a great brahmin might lie down having reached the very height of bliss, so exactly does he rest now.
Close to the Sanskrit
Now, when he is soundly asleep, when he knows nothing whatsoever, the veins called 'hita,' seventy-two thousand in number, extend from the heart to the pericardium; through them, having glided down, he rests in the pericardium. Just as a prince, or a great king, or a great brahmin might lie down, having reached the utmost point of bliss, so exactly does he rest.