These are the subcategories of the Vata Dosha. Vata is responsible for movement, and each vayu governs a different aspect of movement of prana. Note that prana vayu is different from prana. Prana by itself refers to vital life force energy; prana vayu refers to the movement of prana or vital life force energy into the head and chest areas from the crown.
Vayu – Area of Body – Function
prana – head, chest – governs intake, respiration, inspiration, forward momentum
Apana – pelvis – governs elimination, downward movement
Samana – navel – governs assimilation, absorption of food and mental impressions, discernment
Udana – throat – governs speech, expression, growth, muscle movement, upward movement
Vyana – heart & whole body – governs circulation from heart to exterior, expansion