Couli, a term of traditional Chinese medicine, refers to coldness of four limbs. There are cold faint and hot faint.
1. The clear yang qi of nature goes up to heaven and the unclear yin qi comes down to earth. The earth qi is evaporated and goes up to become clouds. The climate condenses and falls down as rain. Rain is transformed from clouds, and clouds are the evaporation of rain.
2. It is the same with the human body. The clear yang qi goes out from the upper orifice.
3. Unclear yin qi goes out from the lower orifice.
4. The clear yang qi fills the skin and muscles and the four limbs. The unclear yin qi moves among the five zang organs and the six fu organs.

Could you explain what you have said in detail?
It's Like this. . . .
1. The east belongs to yang. Yang qi goes up, so the vital yang qi of the human body is gathered on the upper part. This makes the upper part clever and the lower part weak, hence ears and eyes are sharp and hands and feet are clumsy.
2. The west belongs to yin. Yin qi goes down, so the vital yin qi of the human body is gathered on the lower part. This makes the lower part strong and the upper part weak, hence ears and eyes are not sharp but hands and feet are agile.
3. When the upper part of the body is infected by pathogenic wind, the right part is more seriously affected. When the lower part of the body is infected by pathogenic wind, the left side is more seriously affected.
4. This is because the yin and yang existing between the earth and heaven are not omnipotent. Neither are the yin and yang of the human body. So the evil qi will enter through the weak points.
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