Fire yin is heart, pericardium and yang is small intestine, triple heater. Control cycle for these five elements goes like this. As you can see, because of these five elements work together, if one element is out of balance, it will affect other elements. Heart feeds spleen and stomach makes the Qi from food we eat. Liver feeds the Heart by circulating the Qi.
Gall bladder is yang of liver, and produce bile for digestion of the stomach and small intestine.
With strong Heart pumping Qi, lung can pump oxygen. When deficiency in Qi occurs, heat cannot supply enough Qi to Lung, and Lung cannot push fluids out. This is why many heart patients have fluids in lung. Heart is also connected with mind, emotion, and spirits. With strong heart, mind and body is peaceful and stable.