adinatha wrote: Namdrol wrote:
So then what goes down the sides of the neck and into the heart? I see vagus and phrenic nerves. Vagus powers the heart; phrenic the diaphragm.
Optic nerve connects directly into the brain. The way it is described is that this channel is in the central channel. it goes up into the brain and then branches out to the eyes.
Tibetan yogis were pretty good at anatomy (better than Indian yogis, actually), but not perfect -- so yes, Vagus nerve connects to the so called "precious heart" (tsitta rinpoche, in which is located the anahata bindu) from the brain , the basis for the visions.
Well vagus is attached to the cranial nerve nucleus along with the optic, and the phrenic is not. But the phrenic and vagus seem to work together with regard to cardio-pulmonary motor function. So there may be a combination of function described here.
You've said before that the central channel is the arterial system, and the side channels are the venal system and spinal cord. Is this a Dzogchen special description?
Just from looking at them; it appears right and left channels are venal and arterial systems respectively; central channel would be the spinal cord. This would account for the interaction with the optic, vagus and phrenic nerves in the function of Ati yoga sadhana.
In human body it is about bilateral symmetry, only when visualized. But in Ati, there is no visualization of these channels.
Spinal column and nerves develop from father white element, hence they belong to the lalana system. Venous belongs to rasana system. Arterial belongs to Avadhuti system. This is more or less how it is understood in Tibetan medicine
However, there are different ways of explaining avadhuti, outer, inner secret, unique to certain Dzogchen systems.
OTOH, this is not so important -- these channels are only explained in order to differentiate the kati from them and explain that it is not a blood channel or lymphatic channel. Also the element of the kati is fire in Dzogchen, unlike other three which are considered earth (lalana), water (rasana) and air (avadhuti). Confusing, no? Also in some Dogchen texts, lalana is red, rasana is white, so even more confusing.