of water in a pipe. When the water is flowing in one direction placidly,
silt and other things may be deposited at the bottom and are not dis-
turbed to any marked extent by the water. But try to force the water in
opposite directions alternately and you at once disturb the deposit, and if
the process is continued long enough the pipe gets cleaned ultimately.^63Each of the five pr ̄aÓnasor v ̄ayus, vital ‘breaths,’ ‘airs,’ or ‘forces,’ is re-
sponsible for functions within a particular region of the body, as shown
in the table below. Ap ̄ana vayu, ̄ the ‘downward air’ also has the meaning
of displaced pra ̄Óna. When a person is unsteady, confused, or otherwise
disturbed, his pra ̄Ónais not confined within him, but is scattered beyond
his body. A yogin, on the other hand, is “one whose pra ̄Ónais within the
body.”^64 Apana v ̄ ayu ̄ can also refer to impurities in the body, which can be
reduced at the subtle level of pr ̄aÓnic energy by the cleansing force of
pra ̄Ónay ̄ ̄ama. Invoking the HaÓtha Yoga Prad ̄ıpik ̄a’s image of the center of
the body as ‘the seat-of-fire’ [HYP 3.65–66], Desikachar maintains that
defilements in the body interfere with pr ̄aÓnaentering the body. On inha-
lation, pra ̄Ónain the air surrounding the body is drawn into the body
where it meets the apana ̄ or impure air. On exhalation, the apana ̄ moves
toward the pra ̄Óna. The powers of respiration, digestion, and metabolism
in the center of the body are likened to flames, and the energy of pr ̄aÓnain
120 religious therapeutics
The Five V ̄ayusor Vital Forces
Ud ̄ana Vayu: ̄ Rising Air
Operates between throat and top of head, responsible for processes
including speech.
Pra ̄Óna V ̄ayu:Vital Air
Operates between throat and navel, controls, respiration and
circulation.
Samana V ̄ ayu: ̄ Equal Air (carries nutriment, etc., equally to all parts of body)
Operates between navel and heart; its main responsibility is con-
trol of digestion.
Vyana V ̄ ayu: ̄ Pervading Air
Operates throughout the whole body, assisting other vayus ̄. It controls
body movement, gross nerves, and the subtle nad ̄ ̄ısor energy channels.
Apana V ̄ ̄ayu:Downward Air
Operates from navel to soles of feet; controls excretion, and sexual
and reproductive functions.
YBh 3.38^65