When a warrior starts practicing the cultivation, he would first attempt to clear his meridians after his soul was reaching the peak mortal realm. It was the first step on the path of cultivation.
A human's channels consisted of twelve regular meridians and eight special meridians.
The twelve regular meridians spread throughout a person's limbs. They were the three-arm yin meridians (lung, pericardium, heart), three-arm yang meridians (large intestine, triple burner, small intestine), three leg yang meridians (stomach, gall bladder, bladder), and three leg yin meridians (spleen, liver, kidney).
As for the eight special meridians, they spread throughout the body. The two most critical special meridians were the conception and governor's vessels.
The position of the conception and governor's vessels is in the central axis line of a person and will be seen as a straight line from the front.