There are vessels in the body referred to as the Extraordinary Meridians, which help regulate flow of energy through the body. They do this in two ways. First, they connect the main meridians. Their connections ensure that energy flows smoothly throughout the body, and facilitate communication between the organs, supporting their proper function. Second, the Extraordinary Meridians serve as reservoirs of energy, which means they can supply deficiencies or absorb excesses in the main meridians. Because of this function, they are also called vessels.
Two of the most important Extraordinary Meridians are the Governing Vessel and the Conception Vessel. The Governing Vessel runs up the back of the body, from the perineum to the crown of the head, while the Conception Vessel runs down the front of the body, from the crown to the perineum (The perineum is the anatomical point between the sex glands and the anal sphincter). Thus, together, these two meridians encircle the body on its vertical axis. Both run very close to the surface of the body. The path of these meridians also coincides with the network of the central nervous system (CNS). Stimulating the CNS will fill the vessels, and by extension all the meridians the vessels supply.
Along these vessels, there are certain specific points where Qi—as well as blood, other body fluids, and emotions—tend to get blocked. These points are known as gates.