How an Acupuncture needle?

The function of  Three organs
- Stomach, spleen, and lung

Beverages enter stomach
Overflowing essence qi
is transported upward to the spleen.

The spleen qi spreads the essence.
with turns upward to the lung.

[ The latter] frees and regulates the passageways of the water,
it transports [ the water] downward to the urinary bladder.

The essence of water is spread to the four [directions],
it moves through all the five conduits simultaneously.

Added the Kidney

Water [ consumed as ] beverage flows downward [ in the body ] and reaches the triple burner. [There] the water is transformed to finest essence which rises and turns into clouds and fog.
Clouds and fog disperse and flow into the spleen....

[ The qi of ] water and solar transformed together. They rise to nourish the metal of the lung. The metal qi penetrates to the kidneys. Hence [ the text states;] it regulates the waterways. It turns around and flows into the lower burner. The urinary bladder stimulates transformations, which leads to urination.

The basic technique of Acupuncture

Press and rub[the affected area] continuously and [at the same time] apply the needle without pushing [ into the depth]. [In this way] move the qi to the [ place of] insufficiency and the spirit qi may recover.

- Wang Bing, Huang Di Nei Jing Su Wen

A theory of Yin-Yang

Heaven was created by an accumulation of Yang; the Earth was created by an accumulation of Yin. Water and fire are the symbols of Yin and Yang; Yin and Yang are the source of power and the beginning of everything in creation. Yang ascends to Heaven; Yin descends to Earth. Hence the universe represents motion and rest, controlled by the wisdom of nature. Nature grants the power to beget and to grow, to harvest and to store, to finish and to begin anew.
-Nei Ching