“In Bhagavad-gita (7.4-5) it is stated that the eight elements earth, water, fire, air, sky, mind, intelligence and false ego are all products of the Lord’s inferior energy, whereas the living entities, who are seen to utilize the inferior energy, originally belong to the superior energy, the internal potency of the Lord. The eight inferior energies work grossly and subtly, whereas the superior energy works as the central generating force. This is experienced in the human body. The gross elements, namely, earth, etc., form the external gross body and are like a coat, whereas the subtle mind and false ego act like the inner clothing of the body.
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 prana. The air which passes through the rectum as evacuated bodily air is called Apana. The air which adjusts the foodstuff within the stomach and which sometimes sounds as belching is called Samana. The air which passes through the throat and the stoppage of which constitutes suffocation is called the Udana air. Aid the total air which circulates throughout the entire body is called the vyana air. Subtler than these five airs, there are others also. That which facilitates the opening of the eyes, mouth, etc., is called naga air. The air which increases appetite is called krkara air. The air which helps contraction is called kurma 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 dhananjaya air.
All these airs are generated from the center of the heart, which is one only. This central energy is the 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-gita (15.15) as follows:
sarvasya caham hrdi sannivisto mattah smrtir jnanam apohanam ca
vedais ca sarvair aham eva vedyo vedanta-krd veda-vid eva caham
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.
Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Third Canto, Chapter 06 – Text 09