The yang organs are full of chi. Chi often changes. This means that they are sometimes full and sometimes empty. The yang organs play an important role in digestion. A yang organ can be removed without causing death.
Every yin organ is related to a yang organ with a similarly function.
The 5 elements The theory of the 5 elements was developed after the theory of yin and yang and is adding something to it. They are related in a creating and a control cycle. The seasons are for example shown in the creating cycle. The theory is a help for the therapist to understand what he or she is observing. The theory is based on observations and not the other way round.