It comprises lips, tongue, teeth, oral cavity, pharynx, larynx, esophagus, stomach, liver, spleen and small intestine (duodenum, jejunum and ileum). Within six hour, the digestive process transforms the food to its necessary nutrients, which in a period of thirty-five days provide nourishment to seven bodily tissues (dhatus). The digestive biological fire (agni) has its centre in the stomach and governs all the metabolism in the body. The optimal metabolism therefore ensures good digestion, absorption and transformation of food as well as sensual perceptions, nourishment of bodily tissues and cells, strong immune system, vitality, good health, visual perception, body temperature and the colour of the skin. This may therefore become a source of joy, enthusiasm and contentment, stamina, courage and confidence, enhanced stability and patience, stimulating clear thinking, logical reasoning and maintaining cellular intelligence. When the psychosomatic principles of Vata, Pitta and Kapha are in their balance in accordance with the individual constitution, then the harmonic metabolism functions in the body.