अथ योऽयमूर्ध्वमुत्क्रामतीत्येष वाव स प्राणोऽथ योयमावञ्चं संक्रामत्वेष वाव सोऽपानोऽथ योयं स्थविष्ठमन्नधातुमपाने स्थापयत्यणिष्ठं चाङ्गेऽङ्गे समं नयत्येष वाव स समानोऽथ योऽयं पीताशितमुद्गिरति निगिरतीति चैष वाव स उदानोऽथ येनैताः शिरा अनुव्याप्ता एष वाव स व्यानः ॥२.७ ॥
In plain words
Now that which goes upward is the out-breath; that which moves downward is the down-breath; that which sets the coarsest part of the food in the down-breath and carries the finest evenly to every limb is the even breath; that which brings up and swallows down what has been drunk and eaten is the up-breath; and that by which these channels are pervaded is the diffused breath.