"Prana: Vital energy; life-breath; life-force. In the human body the prana is divided into five forms: 1)Prana:the prana moves upwards; 2) Apana: The prana that moves downwards producing the excretory functions in general; 3)Yvana: The prana that holds prana and apana together and produces circulation in the body; 4)Samana: The prana that carries the gosser material of food to the apana and brings the subtler material to each limb; the general forces of digestion; and Udana: The prana which brings up or carries down what has been drunk or eaten; the general force of assimilation."