肾 Shèn

[Golden Dragon Shining]

Found a good resource, sharing.

From http://www.itmonline.org/5organs/kidney.htm

All the essences and fluids of the body's various pathways pour into the kidney. After the kidney has assembled the essential fluids of the body's vessels, it also experiences two ways of drainage: one way is through the sexual urge which draws the essence downward to the sexual centers; once it exits from here it cannot come back into the system, so this is just like the ocean "going to ruins." The other way is the upward dispersal by way of the suctioning affect of true qi, which draws the body's combined essences all the way up to the flower pond (mouth); from here it moves down through the throat into the stomach, lubricating the five organ networks, nourishing all of the body's pathways, and finally returning to the kidney. This is the microcosmic process of ascending and descending that can be compared to the ocean 'dwelling with the stars.'
 

Those who are knowledgeable in the art of nourishing life take care to shut off the lower exit [of jing via ejaculation] while striving to keep the upper pathway [of jing, nourishing the organs and brain] open and unobstructed. In this fashion, there will be a nourishing cycle that is free of leaks. Physical vitality (jing) and mental clarity (shen) will be abundant, nutritive qi (ying) and protective qi (wei) will be strong, inside (water essence) will be sufficient to control fire, and outside (qi) will be sufficient to ward off noxious influences. This is what the art of expelling disease and the art of longevity is all about.

Edited September 19, 2015 by Sionnach

[Marblehead]

Although I do not practice internal alchemy I think some important things were said above.  Things that should be considered by those who do practice.