四十三难曰∶人不食饮，七日而死者，何也？
然∶人胃中常有留谷二斗，水一斗五升。故平人
日再至圊，一行二升半，日中五升，七日五七三斗五升，而留水谷尽矣。故平人不食饮，七日而死
者，水谷津液俱尽，即死矣。
此《灵枢·平人绝谷篇》文，言人之脏腑形骸，精神气血，皆借水谷以资养生，水谷绝则形
与气俱绝矣。平常无病之人，胃满则肠虚，肠满则胃虚，日夜消化，止留三斗五升。人一日食
五升，考《后汉书·南蛮传》曰∶人禀五升。注∶古升小，故曰五升也。若七日不饮食，其所留
之水谷尽，则精气津液皆尽，故死。然病患不饮食，七日不死者，以水谷留积故也，盖留积则为
病矣。
四十四难曰∶七冲门何在？然唇为飞门，齿为户门，会厌为吸门，胃为贲门，太仓下口为幽
门，大肠小肠会为阑门，下极为魄门，故曰七冲门也。
冲者，通要之地。门者，户也。此承上文食饮之入，稽其通行之门径也。唇为飞门者，飞，古与
扉通，扉，户扇也。盖齿为户门，唇为之扇，故曰扉门。《灵枢·忧恚无言篇》曰∶唇者，音声之
扇也，此即其义。会厌为吸门者，会厌为物之所会聚，又能掩闭，勿使误入也。吸者，吸纳处也，
言为五脏声音之出入，呼吸之门户也。胃为贲门者，胃能聚物如仓廪，故曰太仓。贲，犹奔也，贲门
在胃上口，言物入于胃，疾奔而下太仓也。胃之下口接小肠处曰幽门，言深隐之地，与上下出入处
至远也。大肠小肠会为阑门者，会，合也。小肠之下，大肠之上，相接处分阑精血糟粕，各有所归
也。下极为魄门者，魄门即肛门也。魄，古与粕通。《庄子·天道篇》曰∶古人之糟魄已夫？言食
饮至此，精华已去，止存形质之槽粕，故曰魄门也。此七者，皆食饮出入，冲要之道路也。
第四十三难问道：人如果不吃不喝，七天就会死亡，这是为什么呢？
回答说：人的胃中通常留有谷物二斗，水一斗五升。所以健康的人每天两次去厕所排便，每次排出二升半，一天共排出五升，七天共排出三斗五升，这样胃中留存的水谷就排尽了。因此，健康的人如果不吃不喝，七天就会死亡，这是因为水谷津液都耗尽了，所以死亡。
这段文字出自《灵枢·平人绝谷篇》，讲的是人的脏腑形体骸骨、精神气血，都依靠水谷来滋养生命，水谷断绝则形体与气也同时断绝了。平常没有疾病的人，胃满时肠子空虚，肠满时胃子空虚，日夜消化，只留存三斗五升。人每天吃五升食物，考证《后汉书·南蛮传》说：“人禀受五升。”注释说：古代的升比较小，所以说五升。如果七天不饮食，其中留存的水谷就会耗尽，那么精气津液也就都耗尽了，所以死亡。然而病人如果不吃不喝，七天却没有死，是因为水谷在体内留积的缘故，大概留积就成为病了。
第四十四难问道：七冲门在哪里？
回答说：嘴唇是飞门，牙齿是户门，会厌是吸门，胃上口是贲门，太仓（胃）下口是幽门，大肠和小肠交接处是阑门，肛门是魄门，所以称为七冲门。
冲，是交通要道之地。门，就是门户。这是承接上文关于饮食进入的话题，考察其通行的门径。嘴唇称为飞门的，飞，古时候与“扉”相通，扉，就是门扇。因为牙齿是户门，嘴唇就像它的门扇，所以叫飞门（扉门）。《灵枢·忧恚无言篇》说：“嘴唇，是发出声音的门扇”，这就是其中的含义。会厌称为吸门的，会厌是食物汇聚的地方，又能掩闭，防止误入。吸，是吸纳之处，说是五脏声音出入、呼吸的门户。胃称为贲门的，胃能聚集食物像仓库一样，所以叫太仓。贲，通“奔”，贲门在胃的上口，意思是食物进入胃，迅速奔向下面的太仓。胃的下口连接小肠的地方叫幽门，意思是深隐之地，距离上下出入的地方很远。大肠和小肠交接处叫阑门的，会，就是合。在小肠之下，大肠之上，相接处分隔精华、血液和糟粕，各自有归处。肛门称为魄门的，魄门就是肛门。魄，古时候与“粕”相通。《庄子·天道篇》说：“古人的糟粕已经……”意思是饮食到这里，精华已经去除，只剩下形质的糟粕，所以叫魄门。这七个部位，都是饮食出入、交通要道的路径。
Difficulty 43 asks: Why does a person die after seven days without food or drink?
The answer is: The human stomach usually retains two dou of grain and one dan five sheng of water. Therefore, a healthy person defecates twice a day, with each bowel movement expelling two and a half sheng, totaling five sheng per day. Over seven days, this amounts to three dou five sheng, exhausting the retained food and fluids in the stomach. Thus, when a healthy person abstains from food and drink for seven days, they die because the food, fluids, and Jin-Ye (Body Fluids) are completely exhausted.
This passage originates from the *Ling Shu* chapter "Ping Ren Jue Gu" (Normal Persons Without Grain), explaining that the body's zang-fu organs, form, bones, spirit, Qi, and blood all rely on food and drink to nourish life; if food and drink cease, both form and Qi perish. In ordinary, disease-free individuals, when the stomach is full, the intestines are empty, and when the intestines are full, the stomach is empty; through day-and-night digestion, only three dou five sheng remain. A person eats five sheng daily. According to the *Book of Later Han*, Biography of the Nanman, "Humans are endowed with five sheng." The commentary notes that ancient sheng units were smaller, hence the reference to five sheng. If one does not eat or drink for seven days, the retained food and fluids will be exhausted, causing Jing-Qi (Essence-Qi) and Jin-Ye to deplete, leading to death. However, if a patient does not eat or drink for seven days yet survives, it is due to the retention and accumulation of food and fluids within the body; such retention constitutes pathology.
Difficulty 44 asks: Where are the Seven Rush Gates located?
The answer is: The lips are the Fei Men (Flying Gate); the teeth are the Hu Men (Household Gate); the epiglottis is the Xi Men (Inhaling Gate); the upper opening of the Stomach is the Ben Men (Rushing Gate); the lower opening of the Tai Cang (Great Granary, i.e., Stomach) is the You Men (Secluded Gate); the junction of the Large Intestine and Small Intestine is the Lan Men (Screen Gate); and the anus is the Po Men (Chaff Gate). Hence, they are called the Seven Rush Gates.
"Chong" refers to a vital thoroughfare. "Men" means gate. This section follows the previous discussion on the entry of food and drink, examining their pathways of passage. The lips are called the Fei Men because "Fei" was anciently interchangeable with "Fei" (door leaf/shutter). Since the teeth act as the household gate, the lips serve as its shutters, thus termed Fei Men (Shutter Gate). The *Ling Shu* chapter "You Hui Wu Yan" states: "The lips are the shutters of voice," which elucidates this meaning. The epiglottis is called the Xi Men because it is where substances gather and can close off to prevent misdirection. "Xi" denotes the place of inhalation/absorption, serving as the portal for the emergence and exit of the voices of the Five Zang Organs and for respiration. The Stomach is called the Ben Men because the Stomach gathers food like a granhouse, hence named Tai Cang. "Ben" implies rushing; the Ben Men is at the upper opening of the Stomach, indicating that food enters the Stomach and rushes swiftly downward into the Tai Cang. The lower opening of the Stomach connecting to the Small Intestine is called the You Men, signifying a deep and hidden location far from the points of entry and exit above and below. The junction of the Large and Small Intestines is called the Lan Men; "Hui" means convergence. Located below the Small Intestine and above the Large Intestine, this junction separates essence, blood, and waste, directing them to their respective destinations. The anus is called the Po Men; "Po Men" is synonymous with the anus. "Po" was anciently interchangeable with "Po" (chaff/waste). The *Zhuangzi* chapter "Tian Dao" mentions: "The chaff of the ancients..." implying that by the time food reaches here, its essence has been removed, leaving only the physical residue or chaff, hence named Po Men. These seven sites constitute the critical pathways for the entry and exit of food and drink.