Correspondences between the body and the universe have historically not only been seen in terms of the Five Elements, but also of the "Great Numbers" (大數)For example, the number of acu-points has at times been seen to be 365, in correspondence with the number of days in a year; and the number of main meridians – 12 – has been seen in correspondence with the number of rivers flowing through the History of China|ancient Chinese empire.
<br>While the change of yin and yang may seem random, they actual follow a pattern known Xu Xing or the Five Phases, which shows how and when yin will shift to yang and vice versa. Typically, Xu Xing is used to describe the change of seasons and states of elements. For example, Spring giving rise to Early Summer, which turns into Late Summer, which then becomes Fall, then Winter, then Spring again.
[[File:Wu Xing pattern.png|thumb|350px|left|]]<br>In terms of the human body, the organs follow a similar Wu-Xing pattern, called Zang-Fu. Zang refers to organs that are yin in nature. They are the pericardium, heart, liver, spleen, lung, and kidneys. Fu refers to organs that are yang. They are the triple burner, small intestine, large intestine, gall bladder, urinary bladder, and stomach. Each zang has a fu, and every zang-fu pair corresponds to one of the five phases. The diagram below better explains this relationship.<br><br><br><br><br><br><br><br><br><br>
[[File:Zang fu 5 elements.jpg|thumb|450px|left|]]<br>
The chart below shows the analogous relationships between the Xu Xing and Zang-fu organs.
[[File:Xu xing table.png]]
The purpose of the Zang-fu Organs is to produce the Five Vital Substances, which are the five building blocks of life: Qi, Xue (Blood), Jinye (Body Fluids), Jing (Essence), and Shen (Spirit).
==Diagnosis==