'Semen' is an organic
fluid (also known as 'seminal fluid') that usually contains
spermatozoa. It is secreted by the
gonads (sexual glands) and other sexual organs of
male or
hermaphroditic animals for
fertilization of
female ova. The process of discharge is called
ejaculation.
Physiological aspects
Internal and external fertilization
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.
Composition of human semen
Human semen displayed on dark surface after ejaculation
The components of semen come from two sources: sperm, and "seminal plasma". Seminal plasma, in turn, is produced by contributions from the seminal vesicle, prostate, and bulbourethral glands.
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%[1] | Approximately 200- to 500-million spermatozoa (also called ''sperm'' or ''spermatozoans''), produced in the testes, are released per ejaculation. |
| seminal vesicle | 65-75% | amino acids, citrate, enzymes, flavins, fructose (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 (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 | | 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 20x10
6 spermatozoa/ml or more, sperm count of 40x10
6 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.
[2]
Appearance and consistency of human semen
Most semen is white in colour, but grey or even yellowish semen can be normal as well. Blood in the semen can cause a pink or reddish colour and may indicate a medical problem which should be evaluated by a doctor.
After ejaculation, semen first goes through a clotting process and then becomes more liquid. It is postulated that the initial clotting helps keep the semen in the vaginal canal, but
liquefaction frees the sperm to make their longer journey to the ova. Immediately after ejaculation semen is typically a sticky, jelly-like liquid often forming globules. Within 5 to 40 minutes it will become more watery and liquid before finally drying.
[3]
Semen quality
Semen quality is a measure of the ability of semen to accomplish fertilisation. Thus, it is a measure of fertility in a man. It is the sperm in the semen that are of importance, and therefore semen quality involves both sperm quantity and sperm quality.
Semen and transmission of disease
The semen of a disease-free individual is harmless on the
skin. However, semen can be the vehicle for many
sexually transmitted diseases, including
HIV, the
virus that causes
AIDS.
It is also hypothesized that components of semen, such as the
spermatozoa as well as the seminal
plasma, can cause
immunosuppression in the body when introduced to the
bloodstream or
lymph. Evidence for this dates back to
1898, when
Elie Metchnikoff injected a
guinea pig with its own and foreign guinea pig sperm, finding that an
antibody was produced in response; however the antibody was inactive, pointing to a suppression response by the
immune system.
Further research, such as that by S. Mathur and J.M. 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 the T lymphocytes would fall under attack by the body's
B lymphocytes.
[4]
Other semen components shown to spur an immunosuppressive effect are seminal plasma and seminal lymphocytes.
===Blood in the semen (
hematospermia)===
The presence of blood in the semen 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 and
prostate.
Further
semen analysis and other
urogenital system tests might be needed to find out the cause of blood in the semen.
Semen allergy
In rare cases people have been known to experience allergic reactions to seminal fluids, known as human seminal plasma
hypersensitivity.
[5] 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.
The best 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.
[6] 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.
Cultural aspects
Semen and martial arts
Chi Kung and
Chinese medicine places huge emphasis on a form of energy called 精(
pinyin: jing1, also a morpheme denoting "essence" or "spirit")
[7] [8] - 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 Chi Kung 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: yi4 di1 jing1, shi2 di1 xue3, 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: jing1 ye4, literally: fluid of essence/jing) and the term for
sperm is 精子(pinyin: jing1 zi3, literally: basic element of essence/jing), two modern terms with classical reference.
Cultural views
In some cultures, semen is attributed with special properties of
masculinity. For instance, among the
Etoro people of
Papua New Guinea, it is believed that young boys must
fellate their elders and ingest their sperm to achieve proper sexual maturation. This act may also be attributed to the
culturally active homosexuality throughout these and other tribes.
[9]
Aristotle
Aristotle wrote on the importance of semen as follows:
"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."
[10]
"Sperms are the excretion of our food, or to put it more clearly, as the most perfect component of our food"
[11]
If men start to engage in sexual activity at too early an age... 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.
[12]
Sacred semen
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.
Semen is currently and has long been revered by
Buddhist,
Daoist and
Hindu traditions as a very important constituent of human
physiology.
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 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.
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 believed that the flower magically promoted the flow of sperm.
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.
[13]
In primitive mythology semen 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.
[14]
Semen in popular culture
Depiction of semen in art and
popular culture has, for a long time, been considered a
taboo subject.
The Japanese artist
Takashi Murakami is famous for a manga style piece entitled
My Lonesome Cowboy, which features a naked cowboy superhero wielding his own semen as a lasso.
Andres Serrano, whose photos depict bodily fluids such as "Blood and Semen II" (Semen y Sangre II) (1990), became a controversial figure for featuring semen in his work. He was criticized by some for producing offensive art, while others defended him in the name of
artistic freedom.
[15] His photos were featured on the cover art of two
Metallica albums, ''
Load'' and ''
ReLoad'', which feature images made by shining light through a piece of clear plastic on which semen, blood and urine have been splattered and swirled around.
Only recently has semen been depicted (albeit controversially) in
movies such as ''
Kika'' (1993), ''
There's Something About Mary'' (1998) ("a hard-core staple making its debut in a mainstream Hollywood comedy")
[16], ''
Happiness'' (1998), ''
American Pie'' (1999), ''
Scary Movie'' (2000), ''
Scary Movie 2'' (2001), and ''
National Lampoon's Van Wilder'' (2002). ''
Jackass Number Two'' (2006) features a scene where
Chris Pontius drinks horse semen. It has also appeared in the
anime movie ''
End of Evangelion'', which is not otherwise an adult-oriented film.
Euphemisms
A huge variety of
euphemisms and
dysphemisms have been invented to describe semen. For a complete list of terms, see
Sexual slang.
See also
★
Cumshot
★
ejaculation
★
spermatozoon
★
spermatogenesis
★
pre-ejaculate
★
capacitation
★
sexual slang for a list of various commonly used terms for semen.
★
Vasectomy
References
1. uhmc.sunysb.edu
2. Laboratory Manual for the Examination of Human Semen and Semen–Cervical Mucus Interaction, 4th edition, , , World Health Organization, Cambridge University Press, , ISBN 0-521-64599-9
3. Semen and sperm quality
4. Cross-reactivity of sperm and T lymphocyte antigens., Mathur S, Goust J, Williamson H, Fudenberg H, , , Am J Reprod Immunol, 1981
5. [Vulvar contact dermatitis due to seminal allergy: 3 cases], Guillet G, Dagregorio G, Guillet M, , , Ann Dermatol Venereol, 2005
6. IgE-mediated allergy against human seminal plasma., Weidinger S, Ring J, Köhn F, , , Chem Immunol Allergy,
7. http://www.chikung.com/chapter8.html
8. http://www.hunyuantaijiacademy.com/Articles/On%20Qigong.aspx
9. Ritualized Homosexuality in Melanesia, , Gilbert (editor), Herdt, University of California Press, , ISBN 0-520-08096-3
10. Salmon, J. B., Foxhall, L., (1998), Thinking Men: Masculinity and Its Self-representation in the Classical Tradition, (Routledge), pg 158
11. Sumathipala, A., Siribaddana, S.H., Bhugra, D., (2004), Culture-bound syndromes: the story of dhat syndrome. British Journal of Psychiatry. 184: 200-209, table 2
12. Aristotle & Kraut, Richard (1997), Politics, (Richard Kraut, trans.), Oxford University Press, pg 152 [1]
13. The Woman's Dictionary of Symbols and Sacred Objects, , Barbara, Walker, HarperSanFrancisco, , ISBN 0-06-250923-3 ISBN 978-0-06-250923-9
14. 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)
15. http://www.studentbmj.com/issues/01/12/reviews/481.php
16. Review in Rolling Stone
External links
★
Separation and quantification of cholesterol and major phospholipid classes in human semen by high-performance liquid chromatography and light-scattering detection., Grizard G, Sion B, Bauchart D, Boucher D, , , J Chromatogr B Biomed Sci Appl, 2000
★
"factors that affect spermatogenesis"
★
"Does Semen Have Antidepressant Properties?" By Gordon G. Gallup
★
simple article about sperm contents
★
Article about semen addiction
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