The Chinese character of Yin originally referred to the shady side of the mountain, whilst the character for Yang referred to the sunny side of the mountain.
As it wasn’t seen to be good practice to walk with the sun shining directly onto the face, people tended to try and walk with their back to the sun, resulting in the front of the body being shaded.
The front of the body is therefore seen as being Yin and we as go deeper into the body, it is seen as becoming more Yin.
All the Yin channels flow along the front of the body, whilst the Yang channels flow along the back of the body.
Cold and Damp (being Yin substances) are also generally seen to affect the body, especially below the waist.
We also have the idea of Yin organs which store vital substances and rely on the Yang organs.
The Yin organs are called Zang organs and are the Heart, Spleen, Lungs, Kidneys and the Liver. Each Yin organ is paired with a Yang organ into a system called the Zang-Fu – the pairing is as follows:
- Heart and Small Intestine.
- Spleen and Stomach.
- Lungs and Large Intestine.
- Kidney and Bladder.
- Liver and Gall Bladder.
Blood and Body Fluids, being dense (relative to other substances) are seen as Yin substances and a form of Qi – nutritive Qi – which circulates in the internal organs is also seen as Yin.
