One role of the Liver is to mobilize Yang upward to assist the Spleen in raising the "clear" Nutritive Qi to the Lung. Also, the arousal of Qi, via the Gall Bladder (bile), activates the digestive and peristaltic activity of the Stomach and Intestines, further assisting the Spleen in the generation and distribution of Nutritive Qi. In relation to the Liver, the role of the Spleen is to transform the digestate of the Stomach, facilitate the descension of impure Qi into the Lower Burner, and the ascension of "clear and pure" Qi to the Upper Burner. The impure Qi is either further purified and concentrated by the Kidney, or collected and discharged by the Bladder and Large Intestine, while the Pure Qi is transmuted by the alchemy of the Lung (after mingling with the Heavenly Qi of the atmosphere) into the "Righteous" Qi that benefits life. Through their relationship, the Liver and Spleen organize the processes of digestion, transformation, assimilation, and the distribution of finer and coarser substances. Smooth interaction between these Organ Networks maintains nourishment and the unobstructed passage of Qi, Moisture, Essence, and Blood through the Middle Burner.*