The Conception Vessel is the second of the eight extraordinary vessels to carry its own points, and the counterpart of the Governing Vessel. It runs up the midline of the front of the body from the perineum to just below the lower lip, and the tradition calls it the sea of yin, the vessel that governs all the yin channels, exactly mirroring the Governing Vessel's relation to the yang.
Its Chinese name, Ren Mai, is more interesting than the usual English rendering suggests. Ren carries a sense of taking on, bearing or being responsible for, and the vessel's associations in the classical literature include conception and gestation but are not limited to them. Conception Vessel is a serviceable translation of one part of the meaning that has quietly narrowed the term, and some modern translators prefer Directing Vessel or leave it as Ren Mai for that reason.
The tradition associates the vessel with the reproductive and developmental cycles it describes in sevens and eights, and with the front midline points used in a great deal of classical practice.
With the Governing Vessel it forms the microcosmic orbit of Daoist internal alchemy. The atlas describes that as a practice of a living tradition and does not present it as instruction, and as everywhere in this atlas it makes no physiological claim and gives no guidance.