Ren Mai is a channel that goes up the front of the body. It is also known as the conception channel or conception vessel (CV). It starts at the perineum (hui yin) and goes up to the base of the tongue.

Du Mai is a channel that goes up the back and over the head and meets the Ren Mai in the mouth. It is also known as the governing channel or governing vessel (GV).

Cheng ling (GB18) is located about 3 fingers out from bai hui.

Shen shu (BL23) is located about 3 fingers out from ming men (GV4).

The numbers listed above correspond to those taught in American acupuncture schools.

Zhong mai is also known as the central channel.

The lower dan tian is located 3 fingers down from the navel and 7/10 of the distance from front to back.