The Circulation of the Light

The microcosmic orbit
The ch'i is guided up the back, and then is brought down the front of the body, completeing the circuit
sketch from  Mantak and Maneewan Chia Awaken Healing Light of the Tao (Healing Tao Books, 1993), p.425. Blogger Ref  Link http://www.p2pfoundation.net/Multi-Dimensional_Science Instead of a simple ascent of the life-force along the spine to the top of the head, as in Indian Tantra, the Taoist practitioners of "Internal Alchemy" (Nei-Tan) refer to a continual circulation of the ch'i (vitality principle) up the primary yang (positive), back or Governor Channel (tu mai or du mo) and down the primary yin (negative), front or Functional Channel (jen mai or ren mo) of the body.   This is called "The Circulation of the Light," or "The Lesser Heavenly Cycle" (as opposed to the greater cycle of the rotation of stars and constellations) or "Microcosmic Orbit".
However, Ferran Blasco Aguasca has pointed out to me (in an email) that the circulation along the Microcosmic Orbit and the circulation in the center running back and forth from perineum to crown are two different things. There are practices in Chinese Alchemy that emphasize working with the chong channel, the thursting or central channel, which seem to be more similar to what the Indian Tantrics refer to in kundalini yoga

The microcosmic orbit and the channels of control and function

A, G, D, J are the four cardinal points of the microcosmic orbit A-B, A-C, A-E, A-F are the four phases of ascent of positive fire in the channel of control G-H, G-I, G-K, G-A are the four phases of descent of negaative fire in the channel of function M = Heart O = Fire (in the stove - Tan Tien) grafic from Lu K'uan Yü, Taoist Yoga - Alchemy and Immortality,  Rider and Company, London, 1970, p.13

Once the circulation or orbit is established, the ch'i-energy is then guided inward to the centre of the body, where it is progressively refined and transmuted through three centres, the lower, middle, and upper "elixir fields" or tan t'iens; the goal being to create an immortal spirit body through which the adept can function on a higher plane of existence than the ordinary physical body.  Because of the emphasis on the dynamic flow and circulation of ch'i energy, very little importance is placed on the actual chakras themselves, these being at most points or stations of attention within the overall microcosmic orbit.  One can however associate the three tan t'iens - located below the navel, behind the solar plexus, and in the centre of the head - and the heart centre (sometimes also considered the middle tan tien) with chakras.
An excellent book on the basic practice of the Microcosmic Orbit, written in clear language for the modern-day person, is Awaken Healing Light of the Tao by Mantak and Maneewan Chia (Healing Tao Books, 1993).

Taoism	Internal Alchemy	Chakras