Vata energy is divided into five types called vayus, which means air or wind: prana, udan, uyan, saman and apan.
Prana vayu functions in the head, neck and chest region, and the direction of its action is from the atmosphere to the inside of the body. It carries out functions of the sensory organs in the head and acts as a receptor of all external stimuli. Some of the functions of prana vayu are inspiration (inhaling during breathing, which helps in purifying the blood); taking in food and water; receiving impressions through the senses of smell, sound, taste and vision; interpreting these impressions and coordinating reactions to them; mental activities and grasping of knowledge. Prana vayu also keeps the consciousness intact.
Udan vayu, also located in the head, neck and chest, acts in the opposite direction of prana vayu. Its direction is upward and outward, enabling the body to vomit, spit and throw off substances such as carbon dioxide and water during expiration. It also allows us to express ourselves through talking, singing, whistling, etc.; to show emotions through laughter or tears; and to perform actions such as sneezing and blowing.
Vyan vayu functions at the chest and heart region. It acts like a pacemaker, controlling the activity of the heart, and is the initiator of all actions and movements everywhere in the body. Vyan vayu is responsible for circulation of substances in the body to activate muscular movements and to initiate mental activities.
Saman vayu is present in the area of the abdomen, where digestion takes place. Its main function is to ignite the digestive fire and activate the process of digestion by creating peristalsis in intestinal movements. It also helps in the separation and absorption of digested food and carries excretory wastes to the large intestine.
Apan vayu is the primary vayu present at the main seat of vata, in the colon. Its functions are seen in the excretory organs for defecation, in the kidneys and urinary systems, and in the area of reproductive organs. It activates and mobilizes sperm, enables performance of sexual activities, and is central to ovulation, menstruation and the process of childbirth.