This section is from the book "The Beverages of the Chinese; Kung-fu or Tauist Medical Gymnastics; the Population of China; A Modern Chinese Anatomist and A Chapter in Chinese Surgery.", by John Dudgeon. Also available from Amazon: Kung Fu, or Taoist Medical Gymnastics.
To understand the viscera and their structure it is first necessary to know inspiration, expiration and the alimentary canal. The ancients called the part behind the tongue the horc larynx because it waits upon the inspiration and expiration of the air. The how comes from the how of waiting.
This is the upper mouth of the lung vessel (trachea). Behind the larynx is the yen or gullet so called from the yenof swallowing. By the gullet the food enters the stomach and so forms the upper mouth of the stomach vessels (wei-kwan The yen (gullet) receives the food; the how (larynx) the air. For the last 4000 years this has been most surely believed. The book Ling-shu asserts this and no one has dared to correct or challenge the statement. All understand that what is swallowed enters the stomach but there is a serious misunderstanding about the larynx and inspiration and expiration, arising out of a want of knowledge and examination that the large faces of the two lobes of the lungs are turned to the back or spine; that above there are four apices or peaks which are directed to the chest and that below there is a small piece which also looks to the chest; that the lung vessel below divides into two branches (the right and left trachea) which enter the two lobes of the lungs; that each branch divides again into nine middle bifurcations and each of these again into nine little branches and these again into still more minute branches; that at the end of these minute divisions there are no openings; that in appearance they resemble the chi-lin a certain vegetable; that the outer skin (pleura) of the lungs has also no openings. Inside, the lungs contain light white froth. Below the lungs are no openings whatever, so the 24 holes of the ancients have no existence. The ancients said that in inspiration the lungs were filled and that in expiration they were empty. At present I need not minutely controvert this mistake. In inspiration the abdomen is enlarged and not the lungs; in expiration the abdomen becomes small and not the lungs. Inspiration, expiration, the expectoration of phlegm mucus, saliva and such like have nothing to do with the lungs.
Behind the lung vessel (trachea), in front of the stomach vessel (the oesophagus), on the right and left hollow spaces are the two roots of the air vessel, in appearance like tendons, the upper mouth is situated below the (hwei-yen (epiglottis). On the left is the air door (chi-men, on the right the right air door, and these are the vessels from which proceed the phlegm, mucus, saliva, etc.
The ancients considered cough, asthma, hooping cough as lung diseases, because they came from the chest. In treating these diseases which were owing to external causes, they used diaphoretics and so cured the malady; in treating the warm phlegm, they administered cool remedies and cured the disease; with inside inflammation, they used purgatives; in weakness of the air, they prescribed tonics; if the blood got obstructed, they used remedies to disperse it and seeing all these methods successful, they were naturally elated and left books on the subject stating that these were diseases of the lungs. In this way this belief became established; but the ancients were ignorant of the fact that two air doors, a right and left, descend on each sure half way-down on the front of the lung vessel where they unite to form one trunk, like two branches uniting to form one stem, like a tendon, it proceeds downwards and enters the heart and again about the size of a writing pencil, emerging from the heart it turns to the left and proceeds to the back of the heart. On the left side of the lung vessel it passes the lungs and enters in front of the spine and proceeds downwards to the coccyx (the caudal extremity.) This is the wei-tsung vessel (the all defending vessel), popularly called the yao(lumbar) vessel. Within the abdomen there are two vessels, like tendons, the upper goes to the c'hi-fu(air residence); c'hi-fu=to the great omentum or caul or cock's comb oil because it resembles the han-ying flower, so called from the cock's comb. The upper vessel here described may be the gastro-epiploic artery, coming from the cœliac axis or probably the superior mesenteric artery. The c'hi-fu covers and protects the small intestines. The small intestines lie horizontally in the c'hi-fu. Outside the small intestines and inside the c'hi-fu the original or constitutional air of man is stored and preserved. The original air is fire and this fire is the original air. This fire is the vital root of man's life. The food enters the stomach and small intestines and is dissolved by this original air. When this original air is sufficient digestion is easily performed and vice versa difficult. The above relates to the upper abdominal vessel. The lower or descending vessel on the other hand is connected probably with the male spermatic road and the female uterus. I took great pains to accurately observe this latter vessel. I was unable to satisfy myself that I understood it at all well, so I still remain in doubt but I hope some medical scholars who come after me, if they find a good opportunity will with diligence investigate this point and so fill up here my deficiency. This lower vessel is either the inferior mesenteric artery or spermatic arteries which rise from the aorta below the renal arteries.