Mudras connect meridians together to rechannel how bioelectric energy (chi/prana) flows through your body. It's like connecting wires on a circuit board, and on

Mudras connect meridians together to rechannel how bioelectric energy (chi/prana) flows through your body. It's like connecting wires on a circuit board, and only has any real effect if you actually have a reasonable amount of chi flowing round your body. Mudras are supposed to have some kind of effect on your mind (although I haven't experienced much of that), but I've certainly felt urges to e.g. connect the tips of my fingers/thumbs together (as in the classic Buddhist 'palms up' meditation mudra), or touch the tip of my tongue to the roof of my mouth ("Khechari mudra" in kriya yoga) while meditating. Some yogis (ahem) even go so far as to cut the thin bit of skin that connects the tongue to floor of the mouth so that it can be pushed up inside the nasal cavity, behind the soft palette to directly touch the bones between the nostrils. The urge to do this can be great, and apparently can lead to feelings of ecstatic bliss. I feel the urge, but alas, my tongue can't quite hit the spot yet :( But even just touching the tongue to the roof of the soft palette can let you feel a strong increase in tingles entering the centre of the head. So as with much of religion, any sort of communication/symbolism related to mudras come later, and are probably created by people unaware of their biological origins.