With the relationships among the Five Phases in mind, now let's take a look at correlation among the five Jang organs and six Bu organs.

** Liver **

Liver store blood, so it is a clot of blood. Kidney can also be seen as almost a clot of blood. However, Kidney is in the shape of a seed with more rigidity than the Liver. Kidney arranges Essence and Liver stores blood, but when there is an external stimulus, more soft and big Liver is likely to react first. Lung and Heart don't have that much within themselves, and since they are repeating similar activities without rests, they are less sensitive to external stimuli. However, Liver and Kidney store Essence and blood within them and their activities change constantly. It is like the flow of money at the bank change. Spleen, being an Eum-organ, also goes through this kind of change, but not that apparently. Liver initiates the reaction but its' origin is in Kidney. This is why Liver is in between Kidney and Spleen.

As mentioned above, Liver stores a lot of blood. Blood has to keep flowing to be useful. So, Liver always has to care about blood circulation. In 『Hwangjenaegyong: The Yellow Emperor's Internal Classics』 , it says: "Liver is like a general, and plans and schemes are made from here." The "general" means that it leads the group and "plans and schemes are made from here" means that it thinks about leading the team, in here the blood. So, Liver always makes events and move forward. It this is inhibited, anger is generated. This is why Liver is viewed as the organ responsible for developments. There's an opinion on the Japanese Invasion of Korea in 1592 that Toyotomi Hideyoshi, with the overabundant soldiers after Japan was unified, started the war. Much as Toyotomi Hideyoshi was afraid of the complains from the soldiers, Heart, the head of internal organs, is afraid of Liver's complaints the most. Thus, Liver makes blood and pulse and beat to disperse the blood in Liver.

Then, what is "Metal controlling Wood", Lung inhibiting the activities of Liver? Even though Metal suppresses Wood, it doesn't mean that the activities of Liver is completely blocked. It can actually be in cooperative relationship by controlling extreme activities of Liver. Or it can also be understood this way. If you put blood in the atmosphere, a thin membrane develops. Since Lung controls skin and hair, this membrane belongs to the function of Lung. It prevents fluid from flowing out any further. Blood vessels, blood, and bodily fluids all try to spread out from the function of Liver, but with constricting function of Lung, they stop at some point. Growing in stature and stopping at some point, regularities of heartbeat, suppressing anger, or stanching blood is all through the function of Metal controlling Wood.

Then, what is "Wood controlling Soil"? As mentioned earlier, Wood pulls Essence out from Water, while Soil destroys the entire Water to absorb Yang Ki. Normally, Wood pulls moderate amount of Yang Ki from Water and help the activities of Soil. But when Wood itself is out of order, it does not send Yang Ki to Soil, but rather to Heart or muscles, which then inhibits the activities of Soil. It's same as the activation of sympathetic nerve inhibits the activation of parasympathetic nerve. Liver dislikes falling down, so when it is under circumstances where it has to fall down-when you're frightened, you say "Oh, my. My Liver was about to fall.", the Wood Ki of Liver abnormally rises upward in reaction to the falling Ki.

Conversely, what if there is no "Wood controlling Soil"? When Soil, which leads things toward Yang, is not under control, all activities of the body tilt toward Yang, and thus six Bu organs become more active than five Jang organs. And the person eats more, gains weight, and sleeps more. The characteristics of five Jang organs is to the animals, while those of six Bu organs is to the plants. Of these, the animal-like characteristic fades away and only leaves plant-like one behind. So the person rather negotiates and cooperates than compete or fight, gets more negative and passive than optimistic or active, and is conservative than innovative. This tendency is more apparent in "Soil controlling Water", so we'll talk more about it then.

** Heart **

The organ of Fire, Heart, is described in 『Hwangjenaegyong: The Yellow Emperor's Internal Classics』 as "Heart is like the King, and Spirits(神明) originates from it." Comparing Water with Fire, Water is clear but dark while Fire is bright but gets turbid easily. It is from this brightness of Fire that Spirits(神明) originates from. Within the arrangements of the Five Phases, Fire is located in the South, which is, in Asian philosophy, the direction of highest altitude. Likewise, in a person, the head is located on the top, so it is pretty much clear that Spirits(神明) comes from Fire.

What does Heart do in accordance with other organs? Liver manages growth, while Heart controls promotions. Now let's look at what "promotions" actually mean here. At night, most blood of a person goes into Liver. Only a small amount remains outside to flow with the pulse. When morning comes, blood within Liver all come out through blood vessels and disperses all around the body. At this moment, liver gets the help of Essence to send blood out, but this is impossible without the help of Heart. Especially Lung, the organ of Metal, always tries to suppress the activities of Liver, and thus when Heart, the organ of Fire cannot put Metal under control, it is impossible to supply blood throughout the body.

Then, is Heart supplying blood throughout the body only for provision of energy and removal of waste materials, as it is in Western medicine? Of course, supplying energy and removing waste materials are important. But this is not all. As mentioned earlier about relationships among the Five Phases, when the activities of Fire reaches climax, Eum and Yang get together at the position of Soil. All creatures repeat the activity of putting Eum and Yang together and parting them again. This can more apparently observed in plants. Humans, like plants, continue receiving Ki from outside to combine and then part Eum and Yang. Our bodies go through changes with seasons. For instance, our hair differs in summer and winter. Also our skins get more dense in the winter and less dense in the summer to adjust to the environment. The functions of organs and Meridians might as well change with season.

**Spleen**

Organ of Soil, Spleen, is the master of a live creature. The world of unconsciousness is under the control of Kidney and Heart, but in the world of consciousness, where there is greed and will, Spleen has the lead. Korean proverbs, ‘It takes a full stomach to appreciate even the best of scenery.‘ or 'An envious man waxes lean with the fatness of his neighbor.' all express the human characteristics, which is all related to Spleen.

"Soil controlling Water" means that it prohibits Yang Ki from hiding into the body. Spleen pulls Yang Ki out within Water to send to Liver, Kidney, Heart, and Lung for activation. It is like the manager providing the workers with materials and promoting the environment. It especially refers to activities we can consciously notice, like eating food and digesting. Blood circulation or respiration, which are under control of Heart and Kidney continue while we are sleeping, but digestion is only active while we are awake.

To say that Spleen, the Soil, is the master of mentality refers to the fact that it controls the world of consciousness, not the unconsciousness. Since Spleen is Soil, it manages the combination of Eum and Yang. This combination is just a clot of blood, so when it is left alone it will soon break apart. Lung has to help after the two are combined. Lung, with abundant Ki, manages to cover it and also provide Ki to the clot of blood to harden the cover for continuity of the combination.

Let's take a clinical example on the function of Spleen. Kwibitang(decoction for invi gorating the Spleen) is prescribed for forgetfulness. "Kwibi(returning to the Spleen)“ means that it leads back into Spleen. In normal life, the consciousness of human is supposed to follow the intention of Spleen. But when there is a problem in the body, one's consciousness cannot follow as Spleen directs. This leads to palpitation, loss of sleep, and even forgetting the names of close friends, in other words, forgetfulness. In this kind of cases, where the Ki and Blood is no more under control of Spleen, the function of Spleen should be enhanced, and Heart calmed down to put Ki and Blood back to under the control of Spleen.

**Lung**

Now let's look at the functions of Lung. Lung entirely covers up the heart, but in some senses, it also covers liver, spleen, and kidney as well. This is not unrelated to the fact that Lung manages skin and hair and also functions to suppress Ki in the movement of Ki. Heart is to the engine of a car, and Lung is to the cooler. When extreme exercise make us gasp for breath, and we're like to take it as from lack of oxygen. However, we should also not neglect the fact that it's also to cool the heated heart. by taking cool air into Lung. Sighing when we feel oppressed in the chest is also to cool the heated Heart. So when Liver tries to move forward, Lung calms it down and puts it under control. If a person is very impulsive and cannot control him of herself, the person is likely be with weak Lung function. This kind of person should exercise for Lung to even change the personality. Danjun-breathing exercise and Zen-Buddhist meditation are all for controlling respiration, which is medically speaking, for the enhancement of Lung functions. Respiration exercises enhances Lung and suppress the functions of Liver or Heart and thus calm the person down and accumulate energy in the body. Taking deep breaths is not only for cooling Heart but also for Liver, Spleen, and Kidney to calm the body down. In contrast, when we need to exert a lot amount of strength, we have to hold breath to heat up the Lung. The same applies to a weight lifting person adjusting breath before lifting the barbell or a sprinter holding breath. But it's needless to say that these are bad for health.

Holding breath is not always bad. When saliva gets cold and shivering gets excessive, one should talk less and close the mouth and control breath to boost up physiological activities in the body. "Controlling breath" means to inhale more air than exhaling, as if there is remaining air within the lung. This way, the temperature in the lung goes up to raise the physiological temperature for liver and kidney. The most significant role of Lung is to manage Eum and Yang combined at Soil through to activated stage of Wood. Although Eum and Yang are combined at Soil, it is still a clot of blood, which needs Ki and process of drying, cooling, and covering with thick rind, all performed by Lung.

Difficulty in urination is very likely to be referred to as problem in kidney. But this is not always true. It can also originate from dysfuntion of Lung. As dew falls only after temperature goes down in autumn, urine is also seen as moisture that has gone upward falling down with suppressing function of Lung. The urine is discharged through kidney, but its' generation originates from Lung. This is why Korean Medicine treats difficulty in urination by enhancing the functions of Lung. Lung belongs to Metal, and since Metal is metal and mineral, talc or gypsum, which are from stones, is used to help Lung in suppressing function. Medicine from plants with shape of stone or crushed stone are also used: Poria, Fritillariae cirrhosae bulbus, Alismatis Rhizoma, Polyporus, Pinelliae Tuber, Arisaematis Rhizoma, and Trichosanthis Radix. These medicine are mostly white in color and acts on the Ki. Urine is produced from Blood, but is discharged by the function of Ki, so medicine acting on Ki should be used. In contrast, stool is more related to Blood than Ki, so when there is difficulty in bowel movement, medicine acting on Blood should be chosen that acts on Liver and Kidney than on Lung.

A point to think over is that Spleen absorbs nutrition, which is then dispersed throughout the body by Liver and Heart, but which is actually all under the control of Lung. What does this mean? Liver puts Ki out to muscles and Heart provides nutrition to the body through Blood, but this is all controlled by respiration. Lung controls Ki and Blood circulation and also the pathway of the two, the Meridians. This is why Danjun-breathing exercise can control the twelve Meridians.

**Kidney**

Now let's take a look at Kidney. In 『Hwangjenaegyong: The Yellow Emperor's Internal Classics』, Kidney is described as "strength-producing organ where finesse originates from." "Strength-producing organ" refers to the fact that it is the servant for the King, Heart. In the character 腎, there is already 臣 in it. "Strength-producing" means to provide strength to Heart, the master for Kidney. The dignity of the King, the Heart, depends on how much Kidney supports the Heart. "Finesse" means that Kidney performs actual work in place of Heart. In other words, Heart manages brain work, while Kidney manages physical works.

Heart is Yang, like a husband and Kidney is Eum like a wife. Heart takes control of the works outside the body, while Kidney manages the work inside the body. Heart gathers information from outside the body and analyzes it to react through all the organs of the body. This is why Kidney, Liver, Lung, Spleen, six Bu organs, and Meridians all follow Heart. But some jobs are under control of Kidney. Heart puts 精 in custody of Kidney, and Kidney manages child birth and fostering.