以补金匮所未及。人身毛窍之内。则有孙络。孙络之内。则有横络。横络之内。则有经
焉。经与络皆有血也。其孙络横络之血。起于包中之血海。乃冲任脉之所主。（经云。
冲脉于脐左右之动脉是也。脐下为小腹。小腹两旁为少腹。少腹者厥阴肝脏。胞中血海之
所居也。以血海居膀胱之外。名曰胞中。膀胱居血海之内。故曰膀胱者。胞之室也。）
其血则热肉充肤。澹渗皮毛。皮毛而外。肺气主之。皮毛之内。肝血主之。盖以冲任之
血。为肝所主。即所谓血海
之血也。行于络脉。男子络唇口而生髭须。女子月事以时下。此血或表邪迫其妄行。或
肝火炽盛。或暴怒伤肝而吐者。以致胞中之血。不充于肤腠皮毛。反从气冲而上涌于胃
脘。吐此血者。其吐必多。吐虽多而不死。盖以有余之散血也。其经脉之血。则手厥阴
心包主之。乃中焦取汁以奉生身之血也。行于经隧。内养其筋。外荣于脉。莫贵于此。
必不可吐。吐多必死也。经云、阳络伤则吐血。阴络伤则便血。此血海之血也。（即上
所言络血）一息不运。则机针穷。一丝不续。则霄壤判。此经脉之血也。（营行脉中。
This serves to supplement what was not covered in the *Jingui Yaolue* (Essential Prescriptions of the Golden Cabinet). Within the hair follicles of the human body, there are Sunluo (fine collateral vessels); within the Sunluo, there are Hengluo (transverse collateral vessels); and within the Hengluo, there are Jingmai (main meridians). Both the Jingmai and Luomai contain blood. The blood in the Sunluo and Hengluo originates from the Xuehai (Sea of Blood) located in the Baozhong (uterus/cavity), which is governed by the Chongmai (Penetrating Vessel) and Renmai (Conception Vessel). (The classics state: The Chongmai is located at the pulsating arteries on either side of the umbilicus. Below the umbilicus is called the Xiaofu (lower abdomen), and the sides of the lower abdomen are called the Shaofu (hypochondrium/lower lateral abdomen). The Shaofu is the residence of the Jueyin Liver and the Baozhong Xuehai. Because the Xuehai resides outside the Pangguang (Bladder), it is named Baozhong; because the Pangguang resides inside the Xuehai, it is said that the Pangguang is the chamber of the Bao.)
This blood warms the Rou (muscles/flesh) and fills the Fu (skin), permeating into the Maopi (skin and hair). Outside the Maopi, the Feiqi (Lung Qi) governs; inside the Maopi, the Ganxue (Liver Blood) governs. This is because the blood of the Chongmai and Renmai is governed by the Liver, which is precisely the Xuehai mentioned above. It circulates through the Luomai. In men, it causes the growth of beard hair around the lips and mouth; in women, it allows menstruation to occur regularly. If this blood acts recklessly due to external pathogenic factors forcing it, or due to excessive Liver Fire, or due to violent anger injuring the Liver leading to vomiting, the blood in the Baozhong will fail to nourish the skin, subcutaneous tissue, and Maopi. Instead, it surges upward along the Qichong (Qi Surge) pathway to the Weiwann (epigastrium). Those who vomit this blood will experience massive hemorrhage. Although the volume is large, death does not ensue, as this belongs to the surplus scattered blood (collateral blood).
As for the blood in the Jingmai, it is governed by the Shoujueyin Xinbaogong (Pericardium Meridian of Hand-Jueyin). This is the life-sustaining blood derived from the juices extracted in the Zhongjiao (Middle Jiao) to nourish the body. It circulates through the Jingsui (meridian channels), internally nourishing the Jin (tendons/sinews) and externally flourishing the Mai (vessels). Nothing is more precious than this, and it must never be vomited. Excessive vomiting of this blood will inevitably lead to death. The classics state: Injury to Yang Luo results in hematemesis; injury to Yin Luo results in hematochezia/melena. This refers to the Xuehai blood (i.e., the Luo blood mentioned above). If circulation ceases for even a breath, the mechanism of life is exhausted; if a single thread of continuity is broken, the distinction becomes as vast as heaven and earth. This is the blood of the Jingmai. (Ying Qi circulates within the vessels.)