Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize female ova. In humans, seminal fluid contains several components besides spermatozoa: proteolytic and other enzymes as well as fructose are elements of seminal fluid which promote the survival of spermatozoa and provide a medium through which they can move or "swim".
Semen is produced and originates from the seminal vesicle, which is located in the pelvis. The process that results in the discharge of semen is called ejaculation.
Depending on the species, spermatozoa can fertilize ova externally or internally. In external fertilization, the spermatozoa fertilize the ova directly, outside of the female's sexual organs. Female fish, for example, spawn ova into their aquatic environment, where they are fertilized by the semen of the male fish.
During internal fertilization, however, fertilization occurs inside the female's sexual organs. Internal fertilization takes place after insemination of a female by a male through copulation. In low vertebrates (amphibians, reptiles, birds and monotreme mammals), copulation is achieved through the physical mating of the cloaca of the male and female. In marsupial and placental mammals, copulation occurs through the vagina.
During the process of ejaculation, sperm passes through the ejaculatory ducts and mixes with fluids from the seminal vesicles, the prostate, and the bulbourethral glands to form the semen. The seminal vesicles produce a yellowish viscous fluid rich in fructose and other substances that makes up about 70% of human semen.[1] The prostatic secretion, influenced by dihydrotestosterone, is a whitish (sometimes clear), thin fluid containing proteolytic enzymes, citric acid, acid phosphatase and lipids.[1] The bulbourethral glands secrete a clear secretion into the lumen of the urethra to lubricate it.[2]
Sertoli cells, which nurture and support developing spermatocytes, secrete a fluid into seminiferous tubules that helps transport sperm to the genital ducts. The ductuli efferentes possess cuboidal cells with microvilli and lysosomal granules that modify the semen by reabsorbing some fluid. Once the semen enters the ductus epididymis the principle cells, which contain pinocytotic vessels indicating fluid reabsorption, secrete glycerophosphocholine which most likely inhibits premature capacitation. The accessory genital ducts, the seminal vesicle, prostate glands, and the bulbourethral glands, produce most of the seminal fluid.
Seminal plasma of humans contains a complex range of organic and inorganic constituents.
The seminal plasma provides a nutritive and protective medium for the spermatozoa during their journey through the female reproductive tract. The normal environment of the vagina is a hostile one for sperm cells, as it is very acidic (from the native microflora producing lactic acid), viscous, and patrolled by immune cells. The components in the seminal plasma attempt to compensate for this hostile environment. Basic amines such as putrescine, spermine, spermidine and cadaverine are responsible for the smell and flavor of semen. These alkaline bases counteract the acidic environment of the vaginal canal, and protect DNA inside the sperm from acidic denaturation.
The components and contributions of semen are as follows:
Gland |
Approximate % |
Description |
testes |
2–5% |
Approximately 200- to 500-million spermatozoa (also called sperm or spermatozoans), produced in the testes, are released per ejaculation. If a man has undergone a vasectomy, he will have no sperm in the ejaculation. |
seminal vesicle |
65–75% |
amino acids, citrate, enzymes, flavins, fructose (2–5 mg per mL semen,[3] the main energy source of sperm cells, which rely entirely on sugars from the seminal plasma for energy), phosphorylcholine, prostaglandins (involved in suppressing an immune response by the female against the foreign semen), proteins, vitamin C |
prostate |
25–30% |
acid phosphatase, citric acid, fibrinolysin, prostate specific antigen, proteolytic enzymes, zinc (the zinc level is about 135±40 micrograms/ml for healthy men.[4] Zinc serves to help to stabilize the DNA-containing chromatin in the sperm cells. A zinc deficiency may result in lowered fertility because of increased sperm fragility. Zinc deficiency can also adversely affect spermatogenesis.) |
bulbourethral glands |
< 1% |
galactose, mucus (serve to increase the mobility of sperm cells in the vagina and cervix by creating a less viscous channel for the sperm cells to swim through, and preventing their diffusion out of the semen. Contributes to the cohesive jelly-like texture of semen.), pre-ejaculate, sialic acid |
A 1992 World Health Organization report described normal human semen as having a volume of 2 ml or greater, pH of 7.2 to 8.0, sperm concentration of 20×106 spermatozoa/ml or more, sperm count of 40×106 spermatozoa per ejaculate or more, and motility of 50% or more with forward progression (categories a and b) of 25% or more with rapid progression (category a) within 60 minutes of ejaculation.[5]
Semen is typically translucent with white, grey or even yellowish tint. Blood in the semen can cause a pink or reddish colour, known as hematospermia, and may indicate a medical problem which should be evaluated by a doctor if the symptom persists.[6]
After ejaculation, the latter part of the ejaculated semen coagulates immediately,[7] forming globules,[8] while the earlier part of the ejaculate typically does not.[9] After a period typically ranging from 15 – 30 minutes, Prostate-specific antigen present in the semen causes the decoagulation of the seminal coagulum.[10] It is postulated that the initial clotting helps keep the semen in the vagina,[7] while liquefaction frees the sperm to make their journey to the ova.[7]
Main article:
Semen quality
Semen quality is a measure of the ability of semen to accomplish fertilization. Thus, it is a measure of fertility in a man. It is the sperm in the semen that is the fertile component, and therefore semen quality involves both sperm quantity and sperm quality.
Semen can be stored in diluents such as the Illini Variable Temperature (IVT) diluent, which have been reported to be able to preserve high fertility of semen for over seven days.[11] The IVT diluent is composed of several salts, sugars and antibacterial agents and gassed with CO2.[11]
Semen cryopreservation can be used for far longer storage durations. For human sperm, the longest reported successful storage with this method is 21 years.[12]
In addition to its central role in reproduction, some studies have made claims that semen may have certain beneficial effects on human health:
- Antidepressant: One study suggested that vaginal absorption of semen could act as an antidepressant; the study compared two groups of women, one of which used condoms and the other did not.[13][14]
- Cancer prevention: Studies suggested that seminal plasma might reduce breast cancer by "not less than 50 percent."[15][16] This effect is attributed to its glycoprotein and selenium content, with apoptosis being induced by TGF-Beta. A related urban legend parodied these findings and claimed that performing fellatio at least three times a week reduced the risk of breast cancer.[17]
- Preeclampsia prevention: It has been hypothesized that substances in semen condition a mother's immune system to accept the "foreign" proteins found in sperm as well as the resulting fetus and placenta, keeping blood pressure low and thereby reducing the risk of preeclampsia. A study shows that oral sex and swallowing sperm may help make a woman's pregnancy safer and more successful, because she is absorbing her partner's antigens.[18]
Other studies claim adversarial effects:
Semen can be the vehicle for many sexually transmitted diseases, including HIV, the virus that causes AIDS.
Further research, such as that by Mathur and Goust, demonstrated that non-preexisting antibodies were produced in humans in response to the sperm. These antibodies mistakenly recognized native T lymphocytes as foreign antigens, and consequently T lymphocytes would fall under attack by the body's B lymphocytes.[20]
Semen contains many proteins with potent antimicrobial activity against bacteria, fungi and virus [21] [22] [23] . But none of these proteins are not active against Neisseria gonorrhoeae, a common cause of sexually transmitted disease.
Main article:
Hematospermia
The presence of blood in semen or hematospermia may be undetectable (it only can be seen microscopically) or visible in the fluid. Its cause could be the result of inflammation, infection, blockage, or injury of the male reproductive tract or a problem within the urethra, testicles, epididymis or prostate.
It usually clears up without treatment, or with antibiotics, but if persistent further semen analysis and other urogenital system tests might be needed to find out the cause.
In rare cases, people have been known to experience allergic reactions to seminal fluids, known as human seminal plasma hypersensitivity.[24] Symptoms can be either localized or systemic, and may include vaginal itching, redness, swelling, or blisters within 30 minutes of contact. They may also include generalized itching, hives, and even difficulty breathing.
One way to test for human seminal plasma sensitivity is to use a condom during intercourse. If symptoms dissipate with the use of a condom, it is possible that a sensitivity to semen is present. Mild cases of semen allergy can often be overcome by repeated exposure to seminal fluid.[25] In more severe cases, it is important to seek the advice of a physician, particularly in the event that a couple is trying to conceive, in which case, artificial insemination may be indicated.
Scientists at Utrecht University studied the condition whereby some men "get flu-like symptoms such as feverishness, runny nose, extreme fatigue and burning eyes immediately after they ejaculate. Symptoms can last for up to week."[26] This condition is termed post orgasmic illness syndrome or POIS, and it was discovered that this stemmed from an allergy to their own semen, its effects could be cured using hyposensitization therapy or allergen immunotherapy.[26]
A recent study has suggested that semen acts as an antidepressant in women, so that women physically exposed to semen are less likely to suffer from depression. It is thought that the psychological effects of semen are a result of its complex chemical make-up including several mood-altering hormones (testosterone, oestrogen, follicle-stimulating hormone, luteinizing hormone, prolactin and several different prostaglandins). In a scientific survey of 293 college women it was also found that those who did not use condoms were most likely to initiate sex and to seek out new partners as soon as a relationship ended, suggesting that the chemical dependency to semen creates a "rebound effect". The effect of semen on a male sexual partner (as the receiver of semen) is not known.[14][27][28]
Qigong and Chinese medicine place huge emphasis on a form of energy called 精 (pinyin: jīng, also a morpheme denoting "essence" or "spirit")[29][30] – which one attempts to develop and accumulate. "Jing" is sexual energy and is considered to dissipate with ejaculation so masturbation is considered "energy suicide" amongst those who practice this art. According to Qigong theory, energy from many pathways/meridians becomes diverted and transfers itself to the sexual organs during sexual excitement. The ensuing orgasm and ejaculation will then finally expel the energy from the system completely. The Chinese proverb 一滴精,十滴血 (pinyin: yì dī jīng, shí dī xuè, literally: a drop of semen is equal to ten drops of blood) illustrates this point.
The scientific term for semen in Chinese is 精液 (pinyin: jīng yè, literally: fluid of essence/jing) and the term for sperm is 精子 (pinyin: jīng zǐ, literally: basic element of essence/jing), two modern terms with classical referents.
In Ancient Greece, Aristotle remarked on the importance of semen: "For Aristotle, semen is the residue derived from nourishment, that is of blood, that has been highly concocted to the optimum temperature and substance. This can only be emitted by the male as only the male, by nature of his very being, has the requisite heat to concoct blood into semen."[31] According to Aristotle, there is a direct connection between food and semen: "Sperms are the excretion of our food, or to put it more clearly, as the most perfect component of our food."[32]
The connection between food and physical growth, on the one hand, and semen, on the other, allows Aristotle to warn against "engag[ing] in sexual activity at too early an age ... [since] this will affect the growth of their bodies. Nourishment that would otherwise make the body grow is diverted to the production of semen.... Aristotle is saying that at this stage the body is still growing; it is best for sexual activity to begin when its growth is 'no longer abundant', for when the body is more or less at full height, the transformation of nourishment into semen does not drain the body of needed material."[33]
Additionally, "Aristotle tells us that the region round the eyes was the region of the head most fruitful of seed ("most seedy" σπερματικώτατος), pointing to generally recognised effects upon the eyes of sexual indulgence and to practices which imply that seed comes from liquid in the region of the eyes."[34] This may be explained by the belief of the Pythagoreans that "semen is a drop of the brain [τὸ δε σπέρμα εἶναι σταγόνα ἐγκέφαλου]."[35]
Greek Stoic philosophy conceived of the Logos spermatikos ("seminal word") as the principle of active reason that fecundated passive matter.[36] The Jewish philosopher Philo similarly spoke in sexual terms of the Logos as the masculine principle of reason that sowed seeds of virtue in the feminine soul.[37]
The Christian Platonist Clement of Alexandria likened the Logos to physical blood[38] as the "substance of the soul,"[39] and noted that some held "that the animal semen is substantially foam of its blood".[40] Clement reflected an early Christian view that "the seed ought not be wasted nor scattered thoughtlessly nor sown in a way it cannot grow."[41]
In some pre-industrial societies, semen and other body fluids were revered because they were believed to be magical. Blood is an example of such a fluid, but semen was also widely believed to be of supernatural origin and effect and was, as a result, considered holy or sacred.
Dew was once thought to be a sort of rain that fertilized the earth and, in time, became a metaphor for semen. The Bible employs the term “dew” in this sense[citation needed] in such verses as Song of Solomon 5:2 and Psalm 110:3, declaring, in the latter verse, for example, that the people should follow only a king who was virile enough to be full of the “dew” of youth.[citation needed]
It was widely believed, in ancient times, that gemstones were drops of divine semen which had coagulated after having fertilized the earth. There is an ancient Chinese belief that jade, in particular, was the dried semen of the celestial dragon.
Based upon the resemblance of dandelion juice to human semen, it was historically believed that the flower magically promoted the flow of sperm. (This belief probably derives from the doctrine of signatures.)
The orchid’s twin bulbs were thought to resemble the testicles, and there was an ancient Roman belief that the flower sprang from the spilled semen of copulating satyrs.
Barbara G. Walker recounts these examples of sacred semen in The Woman’s Dictionary of Symbols and Sacred Objects, the thesis of which is that myth and folklore show a pre-patriarchic rule by women that was later supplanted by masculine culture.[42]
In primitive mythology around the world, semen is very often considered analogous to breast milk in some way. In the traditions of Bali, it is considered to be the returning or refunding of the milk of the mother in an alimentary metaphor. The wife feeds her husband who returns to her his semen, the milk of human kindness, as it were.[43]
In some systems of medical philosophy, such as traditional Russian medicine and the Vital Force theory of Herbert Nowell, semen is regarded as the product of a complex physiological interaction between a man and a woman (rather than merely the product of the male reproductive system).[citation needed]
Semen stain on carpet seen with and without ultraviolet light
When the British Secret Intelligence Service discovered that semen made a good invisible ink, Sir George Mansfield Smith-Cumming noted of his agents that "Every man (is) his own stylo".[44]
Some reasons for human ingestion of human or other semen are erotic gratification and physical and spiritual benefits.
There is no risk in ingesting the semen of a healthy man. Swallowing semen carries no additional risk other than those inherent in fellatio. Fellatio does carry some transmission risk for sexually transmitted diseases such as HIV or herpes, especially for people with bleeding gums, gingivitis or open sores.[45]
Even if semen is cold before the individual ingests it, viruses can stay active for a long period of time once outside the body.
Research has suggested that performing unprotected oral sex on a person infected with human papillomavirus (HPV) might increase the risk of oral or throat cancer. The study found that 36% of the cancer patients had HPV compared to only 1% of the healthy control group. It is believed that this is due to the transmission of HPV because this virus has been implicated in the majority of cervical cancers.[46]
The volume of semen ejaculate varies. A review of 30 studies concluded that the average was around 3.4 milliliters (ml), with some studies finding amounts as high as 4.99 ml or as low as 2.3 ml.[47] In a study with Swedish and Danish men, a prolonged interval between ejaculations caused an increase of the sperm count in the semen but not an increase of its amount.[48]
In some cultures, semen is attributed with special properties of masculinity. Several tribes of Papua New Guinea, including the Sambia and the Etoro, believe that semen provides sexual maturation among the younger men of their tribe. To them, sperm possesses the manly nature of the tribal elders, and in order to pass down their authority and powers, younger men of their next generation must fellate their elders and ingest their semen. This custom commences among prepubescent males and postpubescents.[49][50] This act may also be attributed to the culturally active homosexuality throughout these and other tribes.[51]
The church father Epiphanius records that the Borborites[52] and other libertine Gnostic sects[53] consumed semen as the Body of Christ. The Pistis Sophia[54] and Testimony of Truth[55] harshly condemn such practices.
In the modern St. Priapus Church, consumption of semen in the presence of others is a form of worship.[56][dubious – discuss]
There are several sexual practices involving the ingestion of semen. They can be done with one or more partners, like snowballing, felching and creampie eating, or with multiple partners, like the practices of bukkake and gokkun, which originate from Japan.
Some dietary supplements have been marketed with claims to increase seminal volume. Like other supplements, including so-called herbal viagra, these are not approved or regulated by the Food and Drug Administration (as licensed medications would be), and none of the claims have been scientifically verified. Similar claims are made about traditional aphrodisiac foods, with an equal lack of verification.
A huge variety of euphemisms and dysphemisms have been invented to describe semen. For a complete list of terms, see sexual slang.
- ^ a b Mann, T (1954). The Biochemistry of Semen. London: Methuen & Co; New York: John Wiley & Sons. http://www.archive.org/stream/biochemistryofse00mann#page/n5/mode/2up
- ^ Guyton, Arthur C. (1991). Textbook of Medical Physiology (8th ed.). Philadelphia: W.B. Saunders. pp. 890–891. ISBN 0-7216-3994-1.
- ^ Harvey, Clare (20 November 1948). "Relation between the Volume and Fructose Content of Human Semen". Nature 162 (4125): 812–813. DOI:10.1038/162812a0. http://www.nature.com/nature/journal/v162/n4125/abs/162812a0.html. Retrieved 22 August 2011.
- ^ Canale D, Bartelloni M, Negroni A, Meschini P, Izzo P.L, Bianchi B, Menchini-Fabris G.F (December 1986). "Zinc in human semen". International Journal of Andrololgy 9 (6): 477–80. PMID 3570537
- ^ World Health Organization (2003). Laboratory Manual for the Examination of Human Semen and Semen–Cervical Mucus Interaction, 4th edition. Cambridge, UK: Cambridge University Press. p. 60. ISBN 0-521-64599-9. http://books.google.com/?id=QBW1LBr-gpUC&pg=PP1&lpg=PP1&dq=Laboratory+Manual+for+the+Examination+of+Human+Semen+and+Semen%E2%80%93Cervical+Mucus+Interaction.
- ^ Blood in Semen – What could cause blood in my semen?
- ^ a b c Gallup, Gordon G; Burch, Rebecca L (2004). "[Semen Displacement as a Sperm Competition Strategy in Humans"]. Evolutionary Psychology 2 (5): 12–23. http://www.epjournal.net/articles/semen-displacement-as-a-sperm-competition-strategy-in-humans/. Retrieved 10 January 2012.
- ^ Dean, Dr. John. "Semen and sperm quality". http://www.netdoctor.co.uk/menshealth/facts/semenandsperm.htm. Retrieved 2006-12-07.
- ^ Baker, Robin R; Bellis, Mark A (1993). "[Human Sperm Competition: ejaculate adjustment by males and the function of masturbation]". Animal Behaviour 46 (5): 861–885. DOI:10.1006/anbe.1993.1271.
- ^ Balk SP, Ko YJ, Bubley GJ (January 2003). "Biology of prostate-specific antigen". J. Clin. Oncol. 21 (2): 383–91. DOI:10.1200/JCO.2003.02.083. PMID 12525533.
- ^ a b Watson, P. F. (1993). "The potential impact of sperm encapsulation technology on the importance of timing of artificial insemination: A perspective in the light of published work". Reproduction, Fertility and Development 5 (6): 691. DOI:10.1071/RD9930691. edit
- ^ Planer NEWS and Press Releases > Child born after 21 year semen storage using Planer controlled rate freezer 14/10/2004
- ^ Jesse Bering (2010), "An ode to the many evolved virtues of human semen", Scientific American, http://www.scientificamerican.com/blog/post.cfm?id=an-ode-to-the-many-evolved-virtues-2010-09-22
- ^ a b Gordon Gallup (2002), "Does Semen Have Antidepressant Properties?", Archives of Sexual Behavior 31: 289–293, ISSN 0004-0002, http://www.springerlink.com/content/wrkl9lc5ueu43rh8
- ^ Lê, Monique G.; Annie Bacheloti, Catherine Hill (1989). "Characteristics of reproductive life and risk of breast cancer in a case-control study of young nulliparous women". Journal of Clinical Epidemiology 42 (12): 1227–33. DOI:10.1016/0895-4356(89)90121-2. PMID 2585013. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T84-4BRKM0D-4T&_coverDate=12/31/1989&_alid=459778230&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5076&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=e80bcbf5baa4f3a9ba95d6bb197659a2. Retrieved 2009-08-13.
- ^ Gjorgov, Arne J. (1978). "Barrier contraceptive practice and male infertility as related factors to breast cancer in married women". Medical Hypotheses 4 (2): 79–88. DOI:10.1016/0306-9877(78)90051-8. PMID 642850. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WN2-4C0CYXX-S7&_user=10&_coverDate=04/30/1978&_alid=459739520&_rdoc=228&_fmt=summary&_orig=search&_cdi=6950&_sort=d&_st=13&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=8ccc92fa1c1ceb0fd5057380d50e2fba. Retrieved 2009-08-13.
- ^ "Fellatio Breast Cancer Reduction". http://www.snopes.com/inboxer/hoaxes/fellatio.asp. Also at about.com Study: Fellatio May Significantly Decrease the Risk of Breast Cancer in Women
- ^ "Correlation between oral sex and a low incidence of preeclampsia : a role for soluble HLA in seminal fluid?". Cat.inist.fr. 1999-12-17. http://cat.inist.fr/?aModele=afficheN&cpsidt=1340021. Retrieved 2012-02-05.
- ^ Muller, Melissa; Kurt J. Sales, Arieh A. Katz and Henry N. Jabbour (2006). "Seminal Plasma Promotes the Expression of Tumorigenic and Angiogenic Genes in Cervical Adenocarcinoma Cells via the E-Series Prostanoid 4 Receptor". Endocrinology (The Endocrine Society) 147 (7): 3356–65. DOI:10.1210/en.2005-1429. PMID 16574793. http://endo.endojournals.org/cgi/content/abstract/147/7/3356?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=Jabbour&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT. Retrieved 2009-08-13.
- ^ Mathur S, Goust J, Williamson H, Fudenberg H (1981). "Cross-reactivity of sperm and T lymphocyte antigens". Am J Reprod Immunol 1 (3): 113–8. PMID 6175235.
- ^ Edström, AM; Malm, J, Frohm, B, Martellini, JA, Giwercman, A, Mörgelin, M, Cole, AM, Sørensen, OE (Sep 1). "The major bactericidal activity of human seminal plasma is zinc-dependent and derived from fragmentation of the semenogelins.". Journal of immunology (Baltimore, Md. : 1950) 181 (5): 3413-21. PMC 2585754. PMID 18714013. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2585754.
- ^ Edström Hägerwall, Anneli M. L.; Rydengård, Victoria, Fernlund, Per, Mörgelin, Matthias, Baumgarten, Maria, Cole, Alexander M., Malmsten, Martin, Kragelund, Birthe B., Sørensen, Ole E., Feldmesser, Marta (2012). "β-Microseminoprotein Endows Post Coital Seminal Plasma with Potent Candidacidal Activity by a Calcium- and pH-Dependent Mechanism". PLoS Pathogens 8 (4): e1002625. DOI:10.1371/journal.ppat.1002625.
- ^ Martellini, JA; Cole, AL, Venkataraman, N, Quinn, GA, Svoboda, P, Gangrade, BK, Pohl, J, Sørensen, OE, Cole, AM (2009). "Cationic polypeptides contribute to the anti-HIV-1 activity of human seminal plasma.". FASEB journal 23 (10): 3609-18. DOI:10.1096/fj.09-131961. PMC 3236594. PMID 19487309. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3236594.
- ^ Guillet G, Dagregorio G, Guillet M (2005). "[Vulvar contact dermatitis due to seminal allergy: 3 cases]". Ann Dermatol Venereol 132 (2): 123–5. PMID 15798560.
- ^ Weidinger S, Ring J, Köhn F (2005). "IgE-mediated allergy against human seminal plasma". Chem Immunol Allergy. Chemical Immunology and Allergy, 2005 88: 128–38. DOI:10.1159/000087830. ISBN 3-8055-7951-9. PMID 16129942.
- ^ a b Kate Kelland (Jan 17, 2011). "Semen allergy suspected in rare post-orgasm illness". LONDON: Reuters. http://www.reuters.com/article/idUSTRE70G00D20110117?loomia_ow=t0:s0:a49:g43:r2:c0.070894:b41084762:z0.
- ^ Tiffany Kary, "Crying Over Spilled Semen", Psychology Today http://www.psychologytoday.com/articles/200210/crying-over-spilled-semen
- ^ Raj Persaud (2002). "Semen acts as an anti-depressant". New Scientist. http://www.newscientist.com/article/dn2457
- ^ Qigong Bible, Chapter #8
- ^ "Home". hunyuantaijiacademy.com. http://www.hunyuantaijiacademy.com/Articles/On%20Qigong.aspx. Retrieved 2012-02-05.
- ^ Salmon, J.B.; L. Foxhall (1998). Thinking Men: Masculinity and Its Self-representation in the Classical Tradition. Routledge. p. 158.
- ^ Sumathipala, A.; S.H. Siribaddana, D. Bhugra (2004). "Culture-bound syndromes: the story of dhat syndrome". British Journal of Psychiatry 184 (3): 200–209. DOI:10.1192/bjp.184.3.200. PMID 14990517. . See table 2.
- ^ Aristotle; Richard Kraut (trans.) (1997). Politics. Oxford UP. p. 152. ISBN 978-0-19-875114-4. http://books.google.com/?id=TxCYKEtShewC&pg=PA152&vq=semen.
- ^ Onians, R. B. (1951). The Origins of European Thought. Cambridge. p. 203. ISBN 0-405-04853-X.
- ^ Diogenes Laertius, Life of Pythagoras, 19. Smith, Justin E. H. (2006). The Problem of Animal Generation in Early Modern Philosophy. Montreal: Concordia University. p. 5. ISBN 978-0-511-21763-0. http://www.cambridge.org/catalogue/catalogue.asp?isbn=978-0-511-21763-0&ss=exc.
- ^ Tripolitis, Antonia (2002). Religions of the Hellenistic-Roman Age. Wm. B. Eerdmans Publishing. pp. 37–38. ISBN 0-8028-4913-X.
- ^ “And when she (intelligence) lives as a comely wife with comely Reason (Logos), that is with virtuous Reason, this self-same Reason himself undertakes the care of her, sowing, like a husband, the most excellent concepts in her.” Philo, De Spec. Leg., § 7. Mead, G.R.S (1906). "Philo of Alexandria and the Hellenistic Theology". Thrice Greatest Hermes: Studies in Hellenistic Theosophy and Gnosis. I. London and Benares: The Theosophical Publishing Society. p. 222. ISBN 0-87728-947-6. http://sacred-texts.com/gno/th1/th111.htm.
- ^ "And that the blood is the Word, is testified by the blood of Abel, the righteous interceding with God." Clement of Alexandria, The Paedagogus, 1, 47.
- ^ Cf. Leviticus 17:14; Clement of Alexandria, The Paedagogus, 1, 39.
- ^ Clement of Alexandria, The Paedagogus, 1, 48.
- ^ Clement of Alexandria, The Paedagogus, 2, 91. See also: Onan.
- ^ Walker, Barbara (October 19, 1988) (Trade PB). The Woman's Dictionary of Symbols and Sacred Objects. San Francisco: HarperSanFrancisco. p. 576. ISBN 0-06-250923-3. http://www.harpercollins.com/books/9780062509239/The_Womans_Dictionary_of_Symbols_and_Sacred_Objects/index.aspx. Retrieved 2007-02-23. ISBN 0-06-250923-3 ISBN 978-0-06-250923-9
- ^ Bellows, Laura J. (2003). http://rspas.anu.edu.au/grc/publications/pdfs/BellowsL_2003.pdf PERSONHOOD, PROCREATIVE FLUIDS, AND POWER: RE-THINKING HIERARCHY IN BALI: Working Paper No. 9 (PDF). Gender Relations Centre, RSPAS, The Australian National University. Retrieved on 2007-02-23. ISSN 1320–4025 (pbk); ISSN 1447–5952 (online)
- ^ The Independent review of The Quest for C: Mansfield Cumming and the founding of the British Secret Service by Alan Judd
- ^ Rosenthal, Sara. The Gynecological Sourcebook, McGraw-Hill Professional, 2003, ISBN 0-07-140279-9 p151
- ^ "Oral Sex Linked To Mouth Cancer Risk ( One of the studies conducted at the Joh...)". Bio-medicine.org. http://www.bio-medicine.org/medicine-news/Oral-Sex-Linked-To-Mouth-Cancer-Risk-5772-1/. Retrieved 2012-02-05.
- ^ A Review of the Physical and Chemical Properties of Human Semen and the Formulation of a Semen Simulant, Derek H, Owen; David F. Katz, Journal of Andrology, Vol. 26, No. 4, July/August 2005. DOI: 10.2164/jandrol.04104
- ^ "Higher sperm counts in Southern Sweden compared with Denmark". Humrep.oxfordjournals.org. http://humrep.oxfordjournals.org/cgi/content/full/17/9/2468. Retrieved 2012-02-05.
- ^ Robert T. Francoeur, Raymond J. Noonan (2004) The Continuum Complete International Encyclopedia of Sexuality p.819
- ^ Semen Warriors Of New Guinea, Hank Hyena, September 16, 1999
- ^ Herdt, Gilbert (editor) (January 28, 1993). Ritualized Homosexuality in Melanesia. University of California Press. ISBN 0-520-08096-3. http://www.ucpress.edu/books/pages/1812.html.
- ^ Epiphanius, Panarion, 26, 4.
- ^ I.e., the Simonians; Epiphanius, Panarion, 21, 4.
- ^ "We have heard that there are men on the earth who take the sperm of men and the flux of women, and mix them with lentils and eat them, saying, 'We believe in Esau and Jacob'" (386–387). Mead, G.R.S (1896). Pistis Sophia. London: The Theosophical Publishing Society. p. 390. ISBN 1-4179-1276-6. http://masseiana.org/pistis_sophia.htm.
- ^ Meyer, Marvin (2007). "The Testimony of Truth". The Nag Hammadi Scriptures. trans. Birger A. Pearson. Harper Collins. p. 624. ISBN 978-0-06-052378-7.
- ^ J. Gordon Melton (1996, 5th ed.). Encyclopedia of American Religions (Detroit, Mich.: Gale) ISBN 0-8103-7714-4 p. 952.