Vata governs movement and air. Each subtype has a seat, or physical location in the body, and is responsible for certain physiological functions. But it's not quite as simple as that, because each dosha and subdosha has emotional, spiritual and psychological role to play, and they do not strictly fit within our ideas of physical limitations. They all interact and many functions are the result of a few sub dosha working together. If one is imbalanced, others will soon follow.
Prana is the primary seat of Vata and indeed of all life. It means something like air, energy or life force. It is located between the bellybutton and the crown of the head moving downwards. Prana is internal and reflective, it receives and absorbs information, energy and substance. Prana governs inhalation, thought, learning, swallowing and creativity. Imbalanced prana may cause insomnia, anxiety or shortness of breath.
Vata Udana Udana moves from the bellybutton up, governing expression. Udana governs change and transformation, giving us will power and the ability grow. Udana is responsible for speaking, burping, sneezing, and hiccoughs. Imbalanced Udana may cause tiredness, earache or a sore throat.
Apana moves from the bellybutton downwards governing expulsion. Apana expels waste in the form of faeces and urine, but also pushes reproductive movement including semen and is responsible for child birth. It can also expel thoughts and emotions which are are negative or no longer useful. Imbalanced Apana can cause constipation or diarrhea, lower back pain or mentrual problems.
Vata Samana Samana moves in a clockwise direction towards the bellybutton. It pushes food through the GI tract. Samana aids digestion of all substances including assimilation of thoughts or experiences, absorbing air in the lungs and all sensory intake. Imbalanced Samana may cause variable digestion, cramps and malnutrition or allergies.
Vata Vyana Vyana moves clockwise away from the bellybutton. Vyana circulates blood, energy, warmth and information around the body. It moves other subdosha around the body to help them do their jobs. Vyana governs the rhythm of the heart and perspiration. Imbalanced Vyana may cause dry skin, dizziness, nervousness, pins and needles or intolerance to heat and cold.