The movements of the body are first generated from the heart, and all the activities of the body are made possible by the senses, powered by the ten kinds of air within the body. The ten kinds of air are described as follows: The main air passing through the nose in breathing is called prāṇa. The air which passes through the rectum as evacuated bodily air is called apāna. The air which adjusts the foodstuff within the stomach and which sometimes sounds as belching is called samāna. The air which passes through the throat and the stoppage of which constitutes suffocation is called the udāna air. And the total air which circulates throughout the entire body is called the vyāna air.
Subtler than these five airs, there are others also. That which facilitates the opening of the eyes, mouth, etc., is called nāga air. The air which increases appetite is called kṛkara air. The air which helps contraction is called kūrma air. The air which helps relaxation by opening the mouth wide (in yawning) is called devadatta air, and the air which helps sustenance is called dhanañjaya air.
All these airs are generated from the center of the heart, which is one only. This central energy is superior energy of the Lord, who is seated within the heart with the soul of the body, who acts under the guidance of the Lord. This is explained in Bhagavad-gītā (15.15) as follows:
sarvasya cāhaṁ hṛdi sanniviṣṭo
mattaḥ smṛtir jñānam apohanaṁ ca
vedaiś ca sarvair aham eva vedyo
vedānta-kṛd veda-vid eva cāham
The complete central force is generated from the heart by the Lord, who is seated there and who helps the conditioned soul in remembering and forgetting. The conditioned state is due to the soul’s forgetfulness of his relationship of subordination to the Lord. One who wants to continue to forget the Lord is helped by the Lord to forget Him birth after birth, but one who remembers Him, by dint of association with a devotee of the Lord, is helped to remember Him more and more. Thus the conditioned soul can ultimately go back home, back to Godhead.
Reference:- SB 3.6.9
