Celestial Chimney

Tiantu, 天突, is the “chimney of heaven” or “what bursts toward heaven.” 天 is the upper region, the head; 突 means to burst forth, to protrude, and also, in its ancient sense, the chimney, the smoke duct that projects from the roof. Both readings coexist: Qi bursting upward, or a conduit passing through toward the heights. The point lies in the jugular fossa, where the trachea leaves the thorax and enters the neck, and the image of the chimney fits the anatomy. It is the same 突 as in ST10, Shuitu, and LI18, Futu.

The Lingshu (Spiritual Pivot) records it in the Ben Shu chapter (本輸), in its enumeration of the points of the neck: «缺盆之中，任脈也，名曰天突», in the center of the fossa between the clavicles, on the Ren Mai, is the point called Tiantu. It is a meeting point of the Ren Mai with the Yin Wei Mai and has always been used for cough and asthma. The Zhenjiu Jiayi Jing (Systematic Classic of Acupuncture and Moxibustion) gives it the alternative name 玉戶, “jade door,” and presents it as the meeting of the Yin Wei Mai and the Ren Mai, in the «中央宛宛中», the central hollow of the neck, located by lowering the head. The reference works add 天瞿.