[ **up: [[Human body]] | [[Reproduction and reproductive systems]]** ] --- # Menstruation [[2025-0314. 'The first day of menstrual bleeding is customarily defined as day one of the menstrual cycle.'|'The first day of menstrual bleeding is customarily defined as day one of the menstrual cycle.']][^1] --- [[2025-0314. 'The first day of menstrual bleeding is customarily defined as day one of the menstrual cycle.'|’In most mammals, endometrial tissue is digested by lysosomal lytic enzymes and extracellular proteases and reabsorbed without external bleeding. In menstruating primates, however, about a third of the endometrial tissue is shed as the menses together with blood from the ruptured microvasculature.’]][^2] [[2025-0314. 'The copious menstrual bleeding of catarrhines is probably not adaptive, but is instead a side effect of ... nourishing the tissue that supports implantation and, ultimately, the fetus itself.'|'The copious menstrual bleeding of catarrhines is probably not adaptive, but is instead a side effect of the design of the microvasculature for its major function: nourishing the tissue that supports implantation and, ultimately, the fetus itself. As a result of this design, catarrhines appear to have too much blood for efficient reabsorption, and copious bleeding is the consequence.']][^3] [[Re. menses – “The copious bleeding of humans and chimps can be attributed to the large size of the uterus relative to adult female body size and to the design of the microvasculature in catarrhines.”]][^4] --- ## Evolution [[2025-0314. 'The function of menstruation is a central enigma of mammalian, and especially primate, reproductive physiology.'|'The function of menstruation is a central enigma of mammalian, and especially primate, reproductive physiology.']][^5] [[2025-0314. 'The function of menstruation is a central enigma of mammalian, and especially primate, reproductive physiology.'|’Each cycle the uterus builds a glandular epithelium with a high secretory capacity and an elaborate microvasculature, only to reabsorb or void it with the menses if implantation does not occur. Why does the endometrium not maintain a steady state of readiness for implantation by the blastocyst? What is the selective advantage of cyclical regeneration and regression?’]][^6] --- ## Primates with Overt Menstruation > - Presbytis entellus > - Papio hamadryas > - Papio c. anubis > - Papio c. papio > - Papio c. ursinu > - Papio c. cynocephalus > - Macaca sinica > - Macaca radiata > - Macaca fascicularis > - Macaca cyclopis > - Macaca mulatta > - Macaca fuscata > - Macaca silenus > - Erythocebus pataas > - Cercopithecus talapoin > - Hylobates lar > - Hylobates hoolock > - Hylobates concolor > - Pan troglodytes > - Homo sapiens > > [^7] --- ## Euphemisms Terminology from Thomas Taylor: [[The “infant in the womb is naturally adapted to be animated in seven months, as an event most paradoxical. For offspring that are born in the seventh month live; but those that are born in the eighth month for most part die.”|“the menstrual purgations.”]][^8] ### Chinese euphemisms for menstruation > - 大姨妈 - Eldest aunt > > - 来事 - The thing comes > > - 例假 - Regular holiday > > - 倒霉 - Bad luck > > - 来那个 - That comes > > - 好朋友 - Good friend > > - 老朋友 - Old friend > > - m到 - M arrives > > - 特殊情况 - Special situation > > - 不方便 - Not convenient > [^9] --- > The term 大姨妈(dà yímā) literally means “older aunt” and is used to refer to “that time of the month” or menstruation. The origin of this term can be traced back to a story from the Han dynasty. There was a girl who was in love with a young man, but she would always use the excuse that her older aunt was visiting whenever he wanted to kiss her. On their wedding night, when the young man saw the girl’s menstrual blood, he asked what was wrong, and she told him that her older aunt had come. As a result, the young man refrained from having sex. Since then, 大姨妈(dà yímā) has been used to refer to menstruation. Additionally, because menstruation occurs regularly every month, it is also called 例假(lìjià) in Chinese. In some regions, people simply say 来事儿了(lái shìr le) to imply menstruation without explicitly mentioning it.[^10] --- ## Belief, legend, idiom ### Ancient Greece #### Hippocratic school [[“When a woman vomits blood, menstruation is a cure.”]][^11] ### Chinese - [[Periods, in China, were often referred to with various euphemisms such as 'the red news' and 'the first tide'.]][^12] + [[Old Chinese folklore formula uses menstrual cloths as one ingredient when seeking to ward off dark magics.]][^13] - [[2024-0727. It was said, in ancient China, said that the menstrual blood of virgins was of medicinal use when it came to sexual troubles.]][^14] ### English [[The “infant in the womb is naturally adapted to be animated in seven months, as an event most paradoxical. For offspring that are born in the seventh month live; but those that are born in the eighth month for most part die.”|“Again, the menstrual purgations in women are for the most part supplied in seven days ...”]][^15] [^1]: Beverly I. Strassman, ‘[[Strassman. ‘The Evolution of Endometrial Cycles and Menstruation’, 1996.|The Evolution of Endometrial Cycles and Menstruation]]’, *The Quarterly Review of Biology*, vol. 71, no. 2 (June 1996), p. 183. [^2]: Beverly I. Strassman, ‘[[Strassman. ‘The Evolution of Endometrial Cycles and Menstruation’, 1996.|The Evolution of Endometrial Cycles and Menstruation]]’, *The Quarterly Review of Biology*, vol. 71, no. 2 (June 1996), p. 183. [^3]: Beverly I. Strassman, ‘[[Strassman. ‘The Evolution of Endometrial Cycles and Menstruation’, 1996.|The Evolution of Endometrial Cycles and Menstruation]]’, *The Quarterly Review of Biology*, vol. 71, no. 2 (June 1996), p. 198. [^4]: Beverly I. Strassman, ‘[[Strassman. ‘The Evolution of Endometrial Cycles and Menstruation’, 1996.|The Evolution of Endometrial Cycles and Menstruation]]’, *The Quarterly Review of Biology*, vol. 71, no. 2 (June 1996), p. 181. [^5]: Beverly I. Strassman, ‘[[Strassman. ‘The Evolution of Endometrial Cycles and Menstruation’, 1996.|The Evolution of Endometrial Cycles and Menstruation]]’, *The Quarterly Review of Biology*, vol. 71, no. 2 (June 1996), p. 181. [^6]: Beverly I. Strassman, ‘[[Strassman. ‘The Evolution of Endometrial Cycles and Menstruation’, 1996.|The Evolution of Endometrial Cycles and Menstruation]]’, *The Quarterly Review of Biology*, vol. 71, no. 2 (June 1996), p. 181. [^7]: Beverly I. Strassman, ‘[[Strassman. ‘The Evolution of Endometrial Cycles and Menstruation’, 1996.|The Evolution of Endometrial Cycles and Menstruation]]’, *The Quarterly Review of Biology*, vol. 71, no. 2 (June 1996), p. 191. [^8]: Thomas Taylor, *[[Taylor. 'The Theoretic Arithmetic of the Pythagoreans', 1816.|The Theoretic Arithmetic of the Pythagoreans]]* (London: J. Valpy, 1816; York Beach, ME: Samuel Weiser, 1972), p. 229. Citations refer to the 1972 edition. [^9]: ’Top euphemisms for “period” by language’, *Clue*, updated 11 March 2016, https://helloclue.com/articles/culture/top-euphemisms-for-period-by-language. [^10]: Cecilia He, ‘Read Between the Lines: 15 Common Chinese Euphemisms’, *Dig Mandarin*, updated 31 August 2023, https://www.digmandarin.com/euphemisms-in-chinese.html. [^11]: *[[Hippocrates. 'Hippocrates. Volume IV', trans. Jones, 1931.|Hippocrates. Volume IV: Heracleitus. On the Universe]]*, translated by W. H. S. Jones (London: William Heinemann, 1931; reprinted in 1967), p. 167. [^12]: Wolfram Eberhard, *[[Eberhard. 'A Dictionary of Chinese Symbols', 1986.|A Dictionary of Chinese Symbols: Hidden Symbols in Chinese Life and Thought]]* (London: Routledge, 1986), s.v. ‘Menstruation’. [^13]: Wolfram Eberhard, *[[Eberhard. 'A Dictionary of Chinese Symbols', 1986.|A Dictionary of Chinese Symbols: Hidden Symbols in Chinese Life and Thought]]* (London: Routledge, 1986), s.v. ‘Menstruation’. [^14]: Wolfram Eberhard, *[[Eberhard. 'A Dictionary of Chinese Symbols', 1986.|A Dictionary of Chinese Symbols: Hidden Symbols in Chinese Life and Thought]]* (London: Routledge, 1986), s.v. ‘Menstruation’. [^15]: Thomas Taylor, *[[Taylor. 'The Theoretic Arithmetic of the Pythagoreans', 1816.|The Theoretic Arithmetic of the Pythagoreans]]* (London: J. Valpy, 1816; York Beach, ME: Samuel Weiser, 1972), p. 229. Citations refer to the 1972 edition.