《难经》左为肾，右为命门。命门者，精神之所舍，原气之所系也，男子以藏精，女子
以系
胞。案《铜人》任脉有石门穴，一名精路，一名命门，一名丹田，在脐下二寸，三焦募也。
其
旁有足少阴四满二穴，一名髓府，去腹中行一寸，足少阴、冲脉之会，是男子之精藏于脐下
二寸也。又关元在脐下三寸，左为胞门，右为子户，去腹中行二寸五分，为足少阴、冲脉之
会。《病源》三十八，胞门、子户主子精，神气所出入合于中，黄门、玉门、四边主持关元
，
禁闭子精。关元主藏魂魄，妇人之胞，三焦之府，常所从止，是妇人之胞系于脐下三寸也。
以此推之，精宫高于胞宫一寸，非同一穴，且命门在十四椎下，去二穴远，当是《难经》混
称之故耳！其称命门者，名同实异也。男子精自石门离宫，至横骨约四寸而出于玉茎，能射
者为有力，不能射者为无力。其与女子交，则茎头当女子中极之下，龙门之次，其泻精正
当关
元，旁当胞门、子户。故《病源》有胞门、子户不受男精之论。《千金》云∶进火之时，当
至阴节间而止。《外台》云∶下精时入玉门半寸许为佳。此茎头当龙门之证。
《脉经》带下有三门∶已产属胞门，未产属龙门，未嫁属玉门。案已产之带，由胎育来
，其
属胞门易晓；若未产即已嫁，其带应由房室来，而属龙门；未嫁之带，应由邪思来，而属玉
门何故？考胞门在关元旁，去脐三寸，再下一寸为中极，一名玉泉，其下有龙门穴，内当交
骨孔中。《千金》云∶龙门在玉泉下，女子入阴内外际。《翼》云∶龙门是阴中上外际是也
。女子伤于丈夫之病，多在龙门。何以言之？《千金》云∶进火之时，当至阴节间而止。盖
谓阴内交骨节间也。《外台》云∶下精时入玉门半寸许为佳。盖玉门内半寸许，正当交骨孔
间，与男子交时，龙门以屡开而伤，故已嫁之带属此。玉门即阴门，在交骨间，无穴。若未
嫁，龙门尚未经开，其因邪思而致营热者，止为病在经络，玉门亦经络外候，故未嫁之带属
此。《脉经》分别绝精。又案《病源》云∶胞门、子户主子精，神气所出入合于中，黄门、
玉门、四边主持关元，禁闭子精。彼论三门浅深同此，则黄门当即龙门。以穴言称龙门，以
门言称黄门，各有当也。妊娠为夫所动，则龙门伤，不能持关元，即致胎堕，故《千金》、
《外台》诸书治胎落，有灸龙门者。
《难经》认为左侧为肾，右侧为命门。命门，是精神寄居的地方，也是原气（元气）系连之处，男子用它来储藏精气，女子用它来系连子宫。查考《铜人腧穴针灸图经》，任脉上有石门穴，又名精路、命门、丹田，位于脐下二寸，是三焦的募穴。其旁边有足少阴肾经的四满穴两个，又名髓府，距离腹中线一寸，是足少阴肾经与冲脉的交会穴，这说明男子的精气储藏于脐下二寸处。另外，关元穴在脐下三寸，左边称为胞门，右边称为子户，距离腹中线二寸五分，是足少阴肾经与冲脉的交会穴。《诸病源候论》卷三十八指出，胞门、子户主管精气，神气由此出入并与中焦相合；黄门、玉门及四周主持关元穴的功能，禁闭子精。关元穴主管藏纳魂魄，是妇女子宫所在，也是三焦的府库，是经常停留之处，这说明妇女的子宫系连于脐下三寸处。据此推断，精宫的位置高于胞宫一寸，并非同一个穴位，而且命门穴位于第十四椎骨下方，距离上述穴位很远，这应该是《难经》混用称呼的缘故！所谓命门，名称相同而实质不同。男子的精气从石门穴离宫出发，到达横骨穴约四寸处，然后从玉茎（阴茎）排出，能够射出说明有力，不能射出说明无力。当男子与女子交合时，阴茎头应当位于女子中极穴之下，龙门穴之旁，射精的位置正当关元穴，旁边对应胞门和子户。因此，《诸病源候论》中有胞门、子户不能容纳男子精液的论述。《千金要方》说：进火（性交）之时，应当到达阴节间就停止。《外台秘要》说：射精时进入玉门半寸左右为佳。这是阴茎头位于龙门穴处的证据。
《脉经》记载带下病分为三门：已生育过的属于胞门，未生育但已出嫁的属于龙门，未出嫁的属于玉门。查考已生育者的带下病，源于胎育而来，归属于胞门容易理解；如果未生育但已出嫁，其带下病应由房事引起，而归属于龙门；未出嫁者的带下病，应由邪思妄念引起，而归属于玉门，这是什么原因呢？考证发现，胞门位于关元穴旁，距离脐部三寸，再下一寸是中极穴，又名玉泉，其下有龙门穴，内部对应交骨孔中。《千金要方》说：龙门穴在玉泉穴下方，对应女子阴道内外交界处。《针灸资生经》说：龙门是指阴户上外侧边缘。女子被丈夫伤害导致的疾病，多发生在龙门穴。为什么这样说呢？《千金要方》说：进火之时，应当到达阴节间就停止。大概是指阴道内交骨的关节之间。《外台秘要》说：射精时进入玉门半寸左右为佳。大概玉门内半寸左右，正当交骨孔之间，与男子交合时，龙门穴因屡次开启而受伤，所以已出嫁者的带下病归属于此。玉门即阴门，位于交骨之间，没有对应的穴位。如果未出嫁，龙门穴尚未经受开启，那些因邪思导致营分有热的，只是经络病变，玉门也是经络的外候，所以未出嫁者的带下病归属于此。《脉经》对此进行了严格区分。又查考《诸病源候论》说：胞门、子户主管精气，神气由此出入并与中焦相合；黄门、玉门及四周主持关元穴，禁闭子精。彼处论述三门深浅与此相同，那么黄门当即龙门。以穴位名称称龙门，以门户名称称黄门，各有其恰当之处。妊娠期间被丈夫触动，则损伤龙门，不能固摄关元，就会导致胎堕，所以《千金要方》、《外台秘要》等书中治疗胎动不安或流产，有用灸龙门穴的方法。
The *Nan Jing* (Classic of Difficult Issues) states that the left side is the Kidney, and the right side is the Mingmen Gate (Gate of Life). The Mingmen Gate is where the spirit resides and where the Yuan Qi (Original Qi) is connected; in men, it stores essence, and in women, it connects to the uterus. According to the *Tong Ren Shu Xue Zhen Jiu Tu Jing* (Bronze Man Acupoint and Moxibustion Atlas), on the Ren Mai (Conception Vessel), there is the Shimen (Stone Door) acupoint, also known as Jing Lu (Essence Path), Mingmen, and Dantian, located two cun below the umbilicus, which is the Mu-Alarm point of the San Jiao (Triple Burner). Beside it are two Saiman (Four Fullness) acupoints of the Foot-Shaoyin Kidney Meridian, also known as Sui Fu (Marrow Mansion), one cun away from the midline of the abdomen, representing the intersection of the Foot-Shaoyin Kidney Meridian and the Chong Mai (Penetrating Vessel); this indicates that male essence is stored at two cun below the umbilicus. Additionally, the Guanyuan (Gate of Great Origin) acupoint is three cun below the umbilicus; its left side is called Baomen (Womb Gate), and its right side is called Zihu (Child's Household), located two cun five fen away from the midline of the abdomen, serving as the intersection of the Foot-Shaoyin Kidney Meridian and the Chong Mai. Volume 38 of the *Bing Yuan* (Source of Diseases) states that Baomen and Zihu govern essence, with Shen Qi (Spiritual Qi) entering and exiting and combining in the middle; Huangmen (Yellow Gate), Yumen (Jade Gate), and the four sides manage the Guanyuan acupoint, sealing and storing zijing (uterine/seed essence). Guanyuan manages the storage of Hun and Po (Soul and Corporeal Soul), is the location of the woman's uterus, and is the mansion of the San Jiao, a place where it frequently rests; thus, the woman's uterus is connected to three cun below the umbilicus. From this, we can deduce that the Jing Gong (Palace of Essence) is one cun higher than the Bao Gong (Uterus), and they are not the same acupoint. Furthermore, the Mingmen acupoint is located below the fourteenth vertebra, far from these points; this is likely due to the mixed usage of terms in the *Nan Jing*. The term "Mingmen" has the same name but different substance. Male essence leaves the palace at Shimen, travels about four cun to the Henggu (Horizontal Bone) acupoint, and exits through the Yujing (Jade Stem/Penis); being able to ejaculate indicates strength, while inability indicates weakness. When copulating with a woman, the glans penis should be positioned below the Zhongji (Central Pole) acupoint and next to the Longmen (Dragon Gate) acupoint; ejaculation occurs precisely at Guanyuan, adjacent to Baomen and Zihu. Therefore, the *Bing Yuan* contains discussions on Baomen and Zihu failing to receive male essence. The *Qian Jin* (Thousand Gold Formulas) states: during intercourse, one should stop when reaching the junction of the yin organs. The *Wai Tai* (External Cabinet) states: for ejaculation, entering about half a cun into the Yumen is optimal. This serves as evidence that the glans penis corresponds to the Longmen acupoint.
The *Mai Jing* (Pulse Classic) categorizes leukorrhea into three gates: for those who have given birth, it belongs to Baomen; for those who have not given birth but are married, it belongs to Longmen; and for those who are unmarried, it belongs to Yumen. Regarding leukorrhea in those who have given birth, originating from pregnancy and childbirth, attributing it to Baomen is easy to understand. However, for those who have not given birth but are married, the leukorrhea should stem from sexual activity and thus belong to Longmen; for the unmarried, it should stem from illicit desires and thus belong to Yumen. Why is this? Examination reveals that Baomen is beside the Guanyuan acupoint, three cun from the umbilicus. One cun further down is the Zhongji acupoint, also known as Yuquan (Jade Spring). Below Yuquan is the Longmen acupoint, internally corresponding to the opening of the pubic symphysis bone. The *Qian Jin* states: Longmen is below Yuquan, corresponding to the inner and outer junction of the female vagina. The *Yi* (Supplement to the Essentials) states: Longmen refers to the upper outer edge of the vulva. Diseases in women caused by their husbands often occur at Longmen. Why? The *Qian Jin* states: during intercourse, one should stop when reaching the junction of the yin organs, referring to the joint space between the internal pubic bones. The *Wai Tai* states: for ejaculation, entering about half a cun into the Yumen is optimal. This half cun inside the Yumen corresponds exactly to the space between the pubic bones. During intercourse, Longmen is injured due to repeated opening, hence leukorrhea in married women is attributed to this. Yumen is the vulva, located between the pubic bones, and has no specific acupoint. For the unmarried, Longmen has not yet been subjected to opening; if illness arises from illicit desires causing heat in the Ying (Nutritive) level, it remains a disease of the meridians. Yumen is also an external manifestation of the meridians, so leukorrhea in the unmarried is attributed to this. The *Mai Jing* makes clear distinctions. Furthermore, the *Bing Yuan* states: Baomen and Zihu govern essence, with Shen Qi entering and exiting and combining in the middle; Huangmen, Yumen, and the four sides manage Guanyuan, sealing and storing zijing. Since the discussion of the depth of the three gates is similar here, Huangmen must be Longmen. Called Longmen when referring to the acupoint, and Huangmen when referring to the gate, each term is appropriate in its context. If a pregnant woman is disturbed by her husband, Longmen is injured and cannot secure Guanyuan, leading to miscarriage. Therefore, texts such as the *Qian Jin* and *Wai Tai* include moxibustion of Longmen in the treatment of threatened abortion or miscarriage.