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Diaphragm (contraception)

Diaphragm (contraception)

The diaphragm is a barrier method of contraception. It is a small soft rubber dome with a flexible rubber 'O'-ring moulded into the edge which the user fills with a spermicidal (sperm killing) cream, foam or gel before placing it in the vagina to wall off the cervix (the opening to the uterus), thus preventing sperm from entering. A diaphragm is very soft and flexible, and can be gently squeezed from its normal circular shape into a thin 'melon-slice' shape for easy insertion. When fully inserted, the rim of this flexible cup (made of latex or medical silicone) sits an inch or so behind the pubic bone, and the rest of the rubber ring then naturally expands into a soft elliptical shape and settles against the front wall of the deepest part of the vagina, surrounding the cervix. It is most effective when used in tandem with spermicide, but if used alone, it is far more effective than spermicide alone. The spermicide should be applied just before insertion, and should be applied to the centre of the dome (which contacts the opening of the cervix) and around the contact surface of the rim.

Use

The diaphragm must be inserted sometime before sexual intercourse and must remain in the vagina for 6 hours after the man's last ejaculation for the spermicide to do its job. The diaphragm is then gently pulled out, washed in warm soapy water, and put away into its case (like a powder compact) ready for the next time. Each diaphragm lasts about six months in normal use.

History

The idea behind the diaphragm has a long history. In medieval times, lemon halves were used to stop sperm from making it into the uterus, and the highly acidic juice acted as a spermicide. The modern rubber form was invented in 1838 and it was later introduced to the United States in 1916 by Margaret Sanger.

Comparisons

Diaphragms are different from cervical caps, which are smaller, thimble-shaped and placed directly over the cervix. Some women with especially long (or rather, deep) vaginas may find it difficult to position cervical caps properly, as their cervixes may be too far back to reach easily. In these cases, using a diaphragm may be more comfortable. The latest variation on diaphragms and cervical caps is Lea's shield, a one-size-fits-all device which stays in place because of suction at the end of the vagina and by this covering the cervix. The diaphragm is an option for couples in which the woman cannot use hormonal forms of contraception (including the pill, norplant, and Depo Provera) for any of a variety of reasons, including having recently undergone a minor cervical procedure (e.g. abnormal cell removal). Diaphragms have advantages and disadvantages when compared to condoms. It does require a little forward-thinking on the part of the woman to insert her diaphragm if she feels that intercourse is likely soon. However, once inserted, intercourse can commence at any time during the next several hours without any pause to apply the condom between foreplay and intercourse. Unlike with condoms, there remains direct intimate skin-to-skin contact, and so the diaphragm does not impair the natural physical sensations of sexual intercourse for either partner. Unlike condoms, diaphragms do not protect against STDs.

Availability

In the US, Diaphragms are available by prescription only, as the correct size must be chosen to suit the individual woman's internal dimensions. They must be initially test-fitted by a health care professional to ensure a good fit. Many European countries do not require prescriptions.

Risks

Diaphragms can lead to an increased risk of cystitis. Although the reasons for this are not fully understood, this may be caused by pressure from the rim of the diaphragm pushing on the neck of the bladder, or by the diaphragm trapping bacteria and secretions in the vagina [http://www.bbc.co.uk/health/ask_doctor/contraception_diaph.shtml]. Diaphragms made of latex must not be used with oil-based lubricants, as they may cause the latex to weaken and crack. Water-based lubricants are safe for use with latex, and are available in most pharmacies.

Further reading


- Halberstam, David. "The Fifties." New York: Fawcett Columbine, 1994.
- McCann, Carole R. "Birth Control Politics in the United States, 1916-1945. Ithaca: Cornell University Press, 1994.
- Tobin, Kathleen. "The American Religious Debate Over Birth Control, 1907-1937. Jefferson: McFarland & Company, 2001.

See also


- List of sex-related topics Category:Contraception

Contraception

:For the Krautrock band, see Birth Control (band) Birth control is a regimen of one or more extra actions, devices, or medications followed in order to deliberately prevent or reduce the likelihood of a woman becoming pregnant. Methods and intentions typically termed birth control may be considered a pivotal ingredient to family planning. Mechanisms which are intended to reduce the likelihood of the fertilization of an ovum by a spermatozoon may more specifically be referred to as contraception. Contraception differs from abortion in that the former prevents fertilization, whereas abortion terminates an already established pregnancy. Methods of birth control which may prevent the implantation of an embryo if fertilization occurs are controversially described by either term — see morning-after pill for a more complete discussion. Birth control is a controversial political and ethical issue in many cultures and religions, and although it is generally less controversial than abortion specifically, it is still opposed by many. There are various degrees of opposition, including those who oppose all forms of birth control short of sexual abstinence; those who oppose forms of birth control they deem "unnatural", while allowing natural family planning; and those who support most forms of birth control that prevent fertilization, but oppose any method of birth control which prevents a fertilized embryo from attaching to the uterus and initiating a pregnancy.

History of birth control

uterus Probably the oldest methods of contraception are coitus interruptus, barrier methods, herbal abortifacients, and attempts to arrange intercourse to coincide with a woman's non-fertile times, colloquially known as the "rhythm method". While it seems as if the rhythm method would have been a good choice, scientists did not figure out the details of the human menstrual cycle until the early 20th century. Due to inconsistencies in the human body, this method is also very unreliable. Coitus interruptus (withdrawal of the penis from the vagina prior to ejaculation) probably predates any other form of birth control. Once the relationship between the emission of semen into the vagina and pregnancy was known or suspected, some men probably managed to think through the haze of passion and withdraw in time. This is not a particularly reliable method of contraception, as the small amount of fluid secreted prior to ejaculation (pre-ejaculate or "Cowper's fluid") can still contain sperm (this is explained below). Folklore has suggested douching immediately following intercourse as a contraceptive method, and while it seems like a sensible idea to try to wash the ejaculate out of the vagina, it does not work due to the nature of the fluids and the structure of the female reproductive tract — if anything, douching spreads semen further towards the uterus. Some slight spermicidal effect may occur if the douche solution is particularly acidic, but overall it is not scientifically observed to be a reliably effective method. The reason both withdrawal and douching are usually not very effective is that the male ejaculate typically consists of approximately 5ml (1 teaspoon) of fluid carrying in excess of 500,000,000 sperm, of which only one is needed to cause reproduction. Thus even a tiny amount of ejaculate can be more than enough. Additionally, prior to ejaculation, a man typically releases small amounts of seminal fluid and sperm ("pre-ejaculate") as a result of becoming sexually aroused, during the erection, and while the penis is being stimulated by the vagina during sexual intercourse. It is theorized that pre-ejaculate is in part an attempt by the penis to assist in lubricating the vagina, and as an attempt to ameliorate the acidity of the female vagina and the male urethra (acidity caused by the usual use of the penis to excrete urine). These small amounts of pre-ejaculate can contain sperm if sperm were present in the urethra as the fluid passed through. And again, only one sperm is needed to cause impregnation. There are historic records of Egyptian women using a pessary (a vaginal suppository) made of various acidic substances (crocodile dung is alleged) and lubricated with honey or oil, which may have been somewhat effective at killing sperm. However, it is important to note that the sperm cell was not discovered until Anton van Leeuwenhoek invented the microscope in the late 17th century, so barrier methods employed prior to that time could not know of the details of conception. Asian women may have used oiled paper as a cervical cap, and Europeans may have used beeswax for this purpose. The condom appeared sometime in the 17th century, initially made of a length of animal intestine. It was not particularly popular, nor as effective as modern latex condoms, but was employed both as a means of contraception and in the hopes of avoiding syphilis, which was greatly feared and devastating prior to the discovery of antibiotic drugs. Various abortifacients have been used throughout human history, but are not considered by some to be birth control. Some of these were effective, some were not; those that were most effective also had major side effects. The ingestion of certain poisons by the female can disrupt the reproductive system; women have drunk solutions containing mercury, arsenic, or other toxic substances for this purpose. The Greek gynaecologist Soranus in the 2nd century AD suggested that women drink water that blacksmiths had used to cool metal. The herbs tansy and pennyroyal are well-known in folklore as abortive agents, but these also "work" by poisoning the woman. Levels of the active chemicals in these herbs that will induce a miscarriage are high enough to damage the liver, kidneys, and other organs, making them very dangerous. However, in those times where risk of maternal death from postpartum complications was high, the risks and side effects of toxic medicines may have seemed less onerous. It is also believed that black cohosh tea will also be effective in certain cases as an abortifacient. There are references in Arabic history to traders inserting a small stone into the uterus of a camel in order to prevent it from conceiving, a concept very similar to the modern IUD, but it seems unlikely that this was used as a contraceptive method for humans since knowledge of the female reproductive tract was very limited until the 20th century, and surgical techniques were poor. Prior to 1939, Gräfenberg's ring, a flexible ring of silver wire, was inserted into the uterus of a woman as a contraceptive. Oral contraceptives did not appear until the mid-20th century, when scientists better understood the process of conception and advances in biochemistry allowed for the isolation (and later synthesis) of the hormones controlling the cycle.

Traditional birth control methods


- celibacy, or sexual abstinence (some may consider these be more properly called alternatives to birth control)
- non-vaginal sex, such as
  - sex without penetration ("outercourse")
  - anal sex or oral sex
- withdrawal, i.e. coitus interruptus
- the rhythm method

Modern birth control methods

rhythm method
- Barrier methods, often combined with a spermicides
  - Condom
  - Female condom
  - Diaphragm: conventional Diaphragm and one-size-fits all version Lea's shield
  - Cervical cap
  - Contraceptive sponge
  - Intra vas device - curently being tested.
- Chemical methods
  - Combined estrogen & progesterone:
    - Combined oral contraceptive pill ("The Pill") and in high single doses as Emergency contraceptive pill
    - Contraceptive patch
    - The Ring (vaginally inserted)
  - Progesterone used alone:
    - Progesterone only pill also used as high single dose Emergency contraceptive pill
    - Depo Provera
    - Implants (such as Norplant)
  - Male oral contraceptive pill
- Intrauterine methods
  - Intrauterine Device ("IUD") which may also be used for Emergency contraception
  - IntraUterine System ("IUS")
- Fertility Awareness Methods aka Natural family planning
  - Basal body temperature
  - Billings ovulation method
  - Sympto-thermal
  - Cervical mucus method
  - Lactational amenorrhea method
- Abortion methods (not considered by some to be birth control, since pregnancy occurs)
  - Surgical abortion
  - Chemical abortion
  - Herbal abortifacients
- Surgical sterilization
  - Tubal ligation for women
  - Vasectomy for men Condoms and herbal birth control methods existed before the modern era. The herbal methods were of various degrees of efficacy, and were available in China and Europe.

Religious and cultural attitudes toward birth control

Protestant Christianity

Christianity in general has had mixed opinions towards contraception and its role in society in recent years. Prior to the 1930s, contraception was generally condemned by all the major branches of Christianity, including by major reformers like Luther and Calvin. This condemnation was relaxed by the Anglican Communion at the 1930 Lambeth Conference, and most Protestant groups followed suit over the course of the 20th century, though some individual Protestants adhere to the traditional view that contraception is wrong. :"The Church of England does not regard contraception as a sin or a contravention of God's purpose." — Church of England, Science, Medicine, Technology and the Environment (2005) [http://www.cofe.anglican.org/info/socialpublic/smte.html#contraception] :"Sex is a powerful drive, and for most of human history it was firmly linked to marriage and childbearing. Only relatively recently has the act of sex commonly been divorced from marriage and procreation. Modern contraceptive inventions have given many an exaggerated sense of safety and prompted more people than ever before to move sexual expression outside the marriage boundary." — Focus on the Family, Abstinence Policy (2005) [http://www.family.org/cforum/fosi/abstinence/] Among Protestant Christianity, the sizeable ELCA, which includes a large number of US Lutheran churches, makes the following statement: :When [having children] is not their intention, the responsible use of safe, effective contraceptives is expected of the male and the female. Respect and sensitivity should also be shown toward couples who do not feel called to conceive and/or rear children, or who are unable to do so. This is a fairly overt acceptance of modern contraceptives. The other major Lutheran and Presbyterian associations, as well as other Protestant groups in general, may take other positions. Since the 1980s, a Protestant, evangelical movement known as Quiverfull has arisen which advocates having large families and not using birth control.

Catholic Christianity

Like pre-1930s Protestantism, the Catholic Church has been morally opposed to contraception and orgasmic acts outside of the context of fully natural marital intercourse as far back as one can historically trace. For instance, the 2nd century Epistle of Barnabas takes it for granted that oral sex is immoral. The official position of the Catholic Church regarding birth control is expressed very clearly in Pope Pius XI's 1930 encyclical entitled Casti Connubii. It was written in response to the Anglican (then-recent) approval of artificial means of contraception when used in cases of grave necessity. :Since, therefore, openly departing from the uninterrupted Christian tradition some recently have judged it possible solemnly to declare another doctrine regarding this question, the Catholic Church, ... in order that she may preserve the chastity of the nuptial union from being defiled by this foul stain, ... proclaims anew: any use whatsoever of matrimony exercised in such a way that the act is deliberately frustrated in its natural power to generate life is an offense against the law of God and of nature, and those who indulge in such are branded with the guilt of a grave sin. In 1968 Pope Paul VI released an encyclical titled Humanae Vitae, which again forbade chemical and barrier methods but suggested natural methods such as the rhythm method or natural family planning might be considered in cases of necessity, a suggestion some see implicit in Casti Connubii as well. These methods are known as "periodic abstinence" and are argued to be morally different from positively modifying the couple's fertility, since the modus operandi is abstinence, albeit not all the time. :"The Church, nevertheless, in urging men to the observance of the precepts of the natural law, which it interprets by its constant doctrine, teaches that each and every marital act must of necessity retain its intrinsic relationship to the procreation of human life." — Pope Paul VI, Humanae Vitae (1968) [http://www.vatican.va/holy_father/paul_vi/encyclicals/documents/hf_p-vi_enc_25071968_humanae-vitae_en.html] Couples seeking marriage in the Catholic Church are in most dioceses required to undergo counseling by a Catholic priest. In the past priests led couples seeking to delay children to rhythm, today they are instructed to point new couples toward the more effective methods of natural family planning. The Church has repeatedly stated its position that condoms are not adequate prevention for sexually transmitted diseases like AIDS, claiming that they are expensive, fallible and liable to provide a false sense of security. Instead the Church argues for sexual abstinence and faithful marital relationships. The Catholic doctrine that using birth control is morally forbidden has been criticized as adding to poverty, destitution and overpopulation. Others argue that the Church's refusal to allow missionaries to endorse morally forbidden practices (such as condom use) in Africa has exacerbated the AIDS epidemic there. In response, the Church notes that there is more than enough food and other resources on the planet for everyone, and that there is no correlation between population density and wealth or poverty. Some of the richest countries in the world have the densest populations, and vice versa. Supporters of birth control argue that economic growth which allows for a high population density without poverty is a direct function of the availability of birth control, as it leads to smaller families who can support themselves and provide their children with education. However, in the USA, for example, births outside of wedlock have dramatically increased since contraception was legalized. While many people in third world countries regard children as their only defense against destitution by serving as providers and support for the extended family, supporters of birth control argue that the dependency on child labor is a vicious cycle. A higher availability of children as labor theoretically pushes down wages; more children require more food, which in turn requires the employment of children to bring in the food. In addition to the argument from the essentially unanimous pre-20th century Christian tradition prohibition contraception, Catholic philosophers have proposed three types of philosophical arguments. These arguments are not official Church teaching, but attempts to give a philosophical argument for what might also be accepted on faith. St. Thomas Aquinas claimed that it was wrong to perform a positive act that deliberately frustrates the primary purpose of a human organ. According to his theory, if the sexual organs have reproduction as their primary purpose, then it follows that contraception is wrong. Opponents of this argument claim that frustration of the primary purpose of an organ is not necessarily wrong (see blindfold or earplug or handcuff) and that the sexual organs have interpersonal union as a co-primary purpose. As a defense of the teaching of Humanae Vitae, Catholic thinkers John Finnis and Germain Grisez gave a new argument. They considered what it is that is wrong about killing people, and concluded that what is wrong about murder is that one is acting directly and positively against the value of human life. Since birth control when it is done by a positive act such as swallowing a pill or putting on a condom (but not when it is "done" in a negative way, i.e., through abstinence), is directly aimed at preventing the formation of life, it is an act directly and positively against the value of human life, and hence wrong. The Finnis and Grisez argument appears to have the consequence that use of non-abortifacient contraception in cases of danger of rape is also wrong when done to prevent conception. However the Catholic Church has no official teaching on the morality of using non-abortifacient contraception (limited to use of condoms or other barrier methods or spermicides) by those being raped. Because the Church teaches that a human life is to be respected from the very moment of conception, any form of contraception known to have the possible effect of destroying a human zygote, embryo or fetus (the pill, IUD, Norplant, or morning after pill, etc.) is considered immoral. Finally, a number of thinkers of the "personalist school", most notably Karol Cardinal Wojtyła, who was to become Pope John Paul II, argued that contraception is contrary to the interpersonal union that sexual intercourse should cement. The most popular form of this argument asserts that sexual union should involve total mutual bodily self-giving if it is not to be a form of self-deceit. Contraception holds back something significant, namely fertility, and hence is argued to be objectively anti-unitive, even if the couple subjectively feels united (that something is held back is clearest in the case of barrier methods, but it is argued that other methods still involve holding something back from giving). But to act anti-unitively is, it is argued, to act against marital love, and this is wrong. A variant version of this argument states that non-contracepted intercourse makes the couple a biological unit. What makes them a biological unit is that their organs are working together, biologically striving for reproduction, even if the intercourse is at a time when reproduction is biologically impossible. But to deliberately and positively act to make reproduction impossible is to set one's will directly against the activity of the organs that are putatively uniting the couple, and hence against the union of the two persons. Some Catholic thinkers have also employed versions of this biological unit account of intercourse to argue against orgasmic homosexual activity.

Islam

The Qur'an does not make any explicit statements about the morality of contraception, but contains statements encouraging procreation. Various interpretations have been set forth over time, and at the time of this writing, discussions on the web can be found easily that take various positions. Early Muslim literature discusses various contraceptive methods, and a study sponsored by the Egyptian government concluded that not only was azl (coitus interruptus) acceptable from a moral standpoint, but any similar method that did not produce sterility was also acceptable. :"It is permissible to use condoms so long as this does not cause any harm and so long as both husband and wife consent to their use, because this is similar to ‘azl (coitus interruptus or “withdrawal”). But it reduces the sensation of pleasure, which is the right of both partners, and reduces the chance of conception, which is also the right of both partners. Neither one of them is allowed to deprive the other of these rights. And Allaah is the course of strength." - islamic-paths.org, Sex and Sexuality in Islam - Condoms (2005) [http://www.islamic-paths.org/Home/English/Issues/Sexuality/Condoms.htm] However, there are several schools of thought on this as well as other issues concerning Islamic morality. In Iran, an Islamic country, contraceptive methods are not only taught to married couples, but also encouraged to youngsters through posters and advertisements.

Judaism

The Jewish view on birth control currently varies between the Orthodox, Conservatve, and Reform branches of Judaism. Among Orthodox Judaism, use of birth control has been considered only acceptable for use in limited circumstances. Conservatives, while generally encouraging its members to follow the traditional Jewish views on birth control has been more willing to allow greater acceptations regarding its use to fit better within modern society. Reform Judaism has generally been the most liberal with regard to birth control allowing individual followers to use their own judgment in what, if any birth control methods they might wish to employ. Among traditional interpretations of the Torah, active prevention of pregnancy is in violation of the commandment "be fruitful and multiply" (Genesis 1:22). Some Rabbinic authorities further consider the possibility (generally not accepted) that a union that by definition cannot lead to pregnancy would amount to "spilling seed", the sin of Onan (Genesis 38:9). The option of contraception is raised by the Talmud (tractate Yevamot 12b), where the use of a pessary is discussed for women who are too young to get pregnant, presently pregnant, or nursing. In each case either the woman or her child is at risk for serious complications, and this is the basis for many rabbinic authorities permitting contraception in situations where pregnancy would seriously harm the woman. In those cases, the most "natural" method is preferred; as the use of a condom or pessary creates a physical barrier, "the pill" (or an intrauterine device) is preferred by most authorities. Contraceptive measures that lead to sterility, especially male sterility (e.g. through vasectomy), are problematic, and a sterilized man may have to separate from his wife (based on Deuteronomy 23:2). Such regulations regarding contraception affect the traditional streams of Judaism (including, but not limited to the Ultra-Orthodox and Modern-Orthodox sects) more so than others because of their strict adherence to Halakhah, or Jewish law. These regulations affect liberal strains of Judaism (including, but not limited to, the Reform, Reconstructionist, and Conservative movements; particularly in Western society) much less, where the emphasis is on applying Halakhah to modern life rather than observing it strictly. Many modern Jews feel that the benefits of contraception, be they female health, family stability, or disease prevention, uphold the commandment in Judaism to "choose life" much more strongly than they violate the commandment to "be fruitful and multiply". When Orthodox Jewish couples contemplate the use of contraceptives, they generally consult a rabbi who evaluates the need for the intervention and which method is preferable from a halachic point of view. Generally, the introduction of oral contraceptives has not caused the stir in Jewish circles that it caused in other religious groups. It was followed by a number of responsa from rabbinic decisors (poskim) which outlined the proper approach to the new phenomenon. There has been surprisingly little talk of the potential risk of increased promiscuity (z'nut). For example, an innovative use of the contraceptive pill in Judaism is employed by young brides. The laws of family purity state that intercourse cannot take place while a woman is menstruating (see niddah). In order to decrease the chance of menstruation occurring just before (or on) the wedding night, many brides briefly regulate their periods in the months leading up to their wedding.

Quotes

Every one believes in birth control....it may be at 2 or 6 or 10, but eventually everyone believes in birth control. -Ray Niehoff

See also


- Population control

References


- Riddle, John M. (1999). Eve's Herbs: A History of Contraception and Abortion in the West. Harvard MA: Harvard University Press. ISBN 0674270266 (An encyclopedic historical study of uses of contraceptive and abortifacient herbs from the ancient world to the modern era by a leading expert on ancient Greek pharmacology.)

External links


- [http://www.orthodoxytoday.org/articles/AnscombeChastity.shtml G. E. M. Anscombe: Contraception and Chastity]
- [http://www.arhp.org/healthcareproviders/resources/contraceptionresources/ Contraception Resource Center from the Association of Reproductive Health Professionals.]
- [http://www.consumerreports.org/main/content/display_report.jsp?FOLDER%3C%3Efolder_id=551087&ASSORTMENT%3C%3East_id=333141&bmUID=1115189369630 A Guide to Condoms and birth control methods.]
- [http://www.alternet.org/rights/22062/ "The Contraception Museum"] (The History of Contraception Museum, Cleveland, Ohio, US.)
- [http://www.birth-control.ws/ Descriptions of various birth control options.]
- [http://news.bbc.co.uk/2/hi/health/3176982.stm Vatican in HIV condom row]
-
- ja:避妊 ko:피임 simple:Birth control

Sperm

A sperm cell, spermatozoon (pl. spermatozoa) (in Greek: sperma = semen and zoon = alive), or spermatozoan, is the haploid cell that is the male gamete. It is carried in fluid called semen, and is capable of fertilising an egg cell to form a zygote. A zygote can grow into a new organism, such as a human being. Sperm cells contain half of the genetic information available to the diploid offspring. Generally, the sex of the offspring is determined by the sperm cells, through the chromosomal pair "XX" (for a female) or "XY" (for a male). Sperm cells were first observed by Antoni van Leeuwenhoek in 1679.

Spermatozoan structure and size

Individual spermatozoa are highly differentiated cells, composed normally of a head, basal body (or midpiece), and tail. The head contains some cytoplasm and the nuclear material for fertilization. The basal body contains a large concentration of mitochondria that provide the energy for sperm mobility through the production of ATP. The spermatozoan tail is typically a flagellum used for propulsion. In humans, sperm cells consists of a head 5 µm by 3 µm and a tail 50 µm long. The Reynolds number associated with spermatazoa is in the order of 1E-2, so it is known that the spermatazoa exhibits laminar flow. Spermatazoan stream lines are straight and parallel. The tail flagellates, which we now know propels the sperm cell (at about 1-3 mm/minute in humans) by rotating like a rudder not side to side like a whip. The cell is characterized by a minimum of cytoplasm. During fertilization, the sperm's mitochondria gets destroyed by the egg cell, and this means only the mother is able to provide the baby's mitochondria and mitochondrial DNA, which has an important application in tracing maternal ancestry. However it has been recently discovered that mitochondrial DNA can be recombinant. The largest spermatozoa belongs to the fruit fly.

Sperm cell production

Main article: Spermatogenesis Spermatozoa are produced in the seminiferous tubules of the testes in a process called spermatogenesis. Round cells called spermatogonia divide and differentiate eventually to become spermatozoa. During copulation the cloaca or vagina gets inseminated, and then the spermatozoa move through chemotaxis to the ovum inside a Fallopian tube or the uterus.

The acrosome reaction

The female ovum is coated in a thick protective membrane. When a sperm cell reaches the egg the acrosome releases its enzymes. These enzymes break down the cell membrane, allowing the sperm cell passage into the egg where the sperm fuses with the egg cells membrane, and empties its genetic content into the egg. Upon penetration the membrane of the egg cell undergoes a change and becomes inpenetratable, preventing further fertilization of the ovum.

See also


- sperm competition
- sperm heteromorphism

External links


- [http://www.andrologysociety.com/resources/handbook.asp The Handbook of Andrology] Category:Reproductive system Category:Germ cells Category:Andrology ja:精子 simple:Sperm

Vagina

The vagina, (from the Latin for "sheath" or "scabbard" ) is the tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the oviduct.

Human vagina

Anatomy

The human vagina is an elastic muscular tube about 4 inches (100 mm) long and 1 inch (25 mm) in diameter that connects the vulva at the outside to the cervix of the uterus at the inside. If the woman stands upright, the vaginal tube points in an upward-backward direction and forms an angle of slightly more than 45 degrees with the uterus. The vaginal opening is at the back (caudal) end of the vulva, behind the opening of the urethra. Above the vagina is Mons Veneris.The inside of the vagina is usually pink, as with all internal mucous membranes in mammals. (In common speech, the term "vagina" is often used improperly to refer to the vulva or female genitals generally; strictly speaking the vagina is a specific internal structure and the vulva is the exterior genitalia only. Calling the vulva the vagina is akin to calling the mouth the throat.) Length, width and shape of the vagina may vary. When a woman gives birth and during sexual intercourse, the vagina widens and lengthens up to 2-3 times. Vaginal lubrication is provided by glands near the vaginal opening and the cervix and also seeps through the vaginal wall (which does not contain any glands). The hymen—a membrane situated behind the urethral opening—partially covers the vagina in many organisms, including some human females, from birth until it is ruptured by sexual intercourse, or by any number of other activities including medical examinations, injury, certain types of exercise, introduction of a foreign object, etc.

Functions of the vagina

From a biological perspective, the vagina performs the following functions:
- Providing a path for menstrual fluids to leave the body.
- Giving birth
- Admitting the male penis for sexual intercourse

Sexual intercourse

The vagina admits the male penis for sexual intercourse and ultimately male sperm for the fertilization of ova for reproduction. Heterosexual post-pubescent males are generally sexually attracted to the human female vagina and the resulting penile erection from such arousal facilitates vaginal penetration. (See: sexual intercourse). The concentration of nerve endings particularly close to the mouth of the vagina causes pleasure to be experienced during sexual activity. The opening of the vagina is home to the clitoris, which is located at the anterior of the vaginal opening; for most women, the clitoris is the main source of sexual pleasure (although it can be too sensitive for direct stimulation in some women). Some women have a very sensitive erogenous zone called "the G-spot" inside their vagina (in the anterior of the vagina, about five cm. in from the entrance), which can produce very intense orgasms if stimulated properly, possibly responsible for the disputed female ejaculation. Not all women have a g-spot that is responsive to stimulation, however.

Giving birth

During live birth, the vagina provides the route to deliver the fetus from the uterus to its independent life outside the body of the mother. During birth, the vagina is often referred to as the birth canal.

Menstruation

The vagina provides a path for menstrual fluids to leave the body. In Western societies, tampons and sanitary towels may be used to absorb these fluids.

Sexual health and hygiene

Other than the penis, fingers or sexual devices, many women insert tampons during menstruation. These must be regularly changed - every four hours at most. Other objects inserted include diaphragms (placed against the cervix, blocking it from sperm), spermicidal cream and lubicrant. Additionally, some women use vaginal douches, which serve to cleanse the vagina with a gentle soap intended to remove odor. These days, such treatment is advised against by doctors, as it may upset the balance of bacteria in the vagina, rather than helping it. Thus, the vagina itself needs no particular treatment in the name of basic hygiene. The vagina is examined during gynecological exams, often using an instrument called a speculum, which keeps the vagina open for visual inspection or taking of samples (see pap smear). Various disorders can affect the vagina, including vaginal cancer and yeast infections. See vulvovaginal health.

The vagina and popular culture

Sexual organs being stimagtised in practically all human cultures, it is not surprising that Western society treats the subject as somewhat taboo. A one-person play by Eve Ensler known as The Vagina Monologues was a rare example of the word appearing in mainstream culture. The popular TV series Sex and the City contains many discussions about the vagina and its health.

See also


- WikiSaurus:vagina — the WikiSaurus list of synonyms and slang words for the vagina in many languages.
- vulva
- vagina dentata
- vulvovaginal disorders
- vagina tightening and toning
- vulvovaginal health
- Skene's glands
- artificial vagina
- gamete

External links


- [http://www.the-clitoris.com/ The-Clitoris.com]
- [http://www.scarleteen.com/body/female_anatomy.html Pink Parts] - "Walk through" of female sexual anatomy by noted sex activist and educator Heather Corinna (illustrations; no explicit photos) Category:Reproductive system Category:Gynecology ja:膣 simple:Vagina

Uterus

The uterus or womb is the major female reproductive organ of most mammals, including humans. One end, the cervix, opens into the vagina; the other is connected on both sides to the fallopian tubes. In mammals, the four main forms in which it is found are: bipartite, as in cows; bicornuate, as in pigs; simplex, as with the pear-shaped one found in humans and horses; and duplex, found in rabbits.

Development

The bilateral Müllerian ducts form during early fetal life. In males, MIF secreted from the testes leads to their regression. In females these ducts give rise to the Fallopian tubes and the uterus. In humans the lower segments of the two ducts fuse to form a single uterus, however, in cases of uterine malformations this development may be disturbed. The different uterine forms in different mammals are due to various degrees of fusion of the two Müllerian ducts.

Anatomy

The uterus is located in the pelvis immediately dorsal (and usually somewhat rostral) to the urinary bladder and ventral to the rectum. It is held in place by eight ligaments (one anterior; one posterior; two lateral or broad; two uterosacral; and two round ligaments). It is usually slightly anteverted (tipped forward) but is sometimes retroverted (tipped backwards). Outside of pregnancy, its size is several centimeters in diameter. The uterus mostly consists of muscle, known as myometrium. The innermost layer of myometrium is known as the junctional zone, which becomes thickened in adenomyosis. The lining of the uterine cavity is called the endometrium. In most mammals, including humans, the endometrium builds a lining periodically which, if no pregnancy occurs, is shed or reabsorbed. Shedding of the endometrial lining in humans is responsible for menstrual bleeding (known colloquially as a woman's "period") throughout the fertile years of a female and for some time beyond. In other mammals there may be cycles set as widely apart as six months or as frequently as a few days. The loose surrounding tissue is called the parametrium.

Function

The main function of the uterus is to accept a fertilized ovum which becomes implanted into the endometrium, and derives nourishment from blood vessels which develop exclusively for this purpose. The fertilized ovum becomes an embryo, develops into a fetus and gestates until childbirth. Due to anatomical barriers such as the pelvis, the uterus is pushed partially into the abdomen due to its expansion during pregnancy. Even in pregnancy the mass of a human uterus amounts to only about a kilogram (2.2 pounds).

Pathology

Some pathological states include:
- prolapse of the uterus
- carcinoma of the cervix - malignant neoplasm
- carcinoma of the uterus - malignant neoplasm
- ectopic pregnancy
- fibroids - benign neoplasms
- adenomyosis - ectopic growth of endometrial tissue within the myometrium

Terminology

The term uterus is commonly used within the medical and related professions, whilst the term womb is in more common usage.

See also


- WikiSaurus:womb — the WikiSaurus list of synonyms and slang words for the womb in many languages
- myoma
- myometrium
- egg (ovum)
- ovary
- menopause
- vulva
- penis

External links


- [http://education.yahoo.com/reference/gray/subjects/subject?id=268 Gray's]
- [http://bioweb.wku.edu/courses/Biol131/images/uterus.jpg Illustration] Category:Pelvis Category:Reproductive system zh-min-nan:Seⁿ-kiáⁿ-tē ja:子宮

Cervix

The cervix (from Latin "neck") is actually the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall. Approximately half its length is visible with appropriate medical equipment; the remainder lies above the vagina beyond view. It is occasionally called "cervix uteri", or "neck of the uterus".

Anatomy

Ectocervix

The portion projecting into the vagina is referred to as the portio vaginalis or ectocervix. On average, the ectocervix is 3 cm long and 2.5 cm wide. It has a convex, elliptical surface and is divided into anterior and posterior lips.

External Os

The ectocervix's opening is called the external os. The size and shape of the external os and the ectocervix varies widely with age, hormonal state, and whether the woman has had a vaginal birth. In women who have not had a vaginal birth the external os appears as a small, circular opening. In women who have had a vaginal birth, the ectocervix appears bulkier and the external os appears wider, more slit-like and gaping.

Endocervical Canal

The passageway between the external os and the uterine cavity is referred to as the endocervical canal. It varies widely in length and width, along with the cervix overall. Flattened anterior to posterior, the endocervical canal measures 7 to 8 mm at its widest in reproductive-aged women.

Internal Os

The endocervical canal terminates at the internal os which is the opening of the cervix inside the uterine cavity.

Cervical Mucus

Normally the external os is blocked by a thick mucus that prevents infection, however the mucus thins when ovum are ready to be fertilized, allowing spermatazoa to pass through the cervix. Most oral contraceptives increase their effectiveness by not allowing this mucus to thin, therefore blocking spermatazoa from passing even when ovum are ready to be fertilized. During pregnancy the cervix is completely blocked by a special antibacterial mucosal plug which prevents infection as before. The mucous plug comes out as the cervix dialates in labor or shortly before.

Functionality

During orgasm, the cervix convulses and the external os dilates. Dr. R. Robin Baker and Dr. Mark A. Bellis, both at the University of Manchester, first proposed that this behavior worked in such a way as to draw any semen in the vagina into the uterus, increasing the likelihood of conception. Later researchers, most notably Elisabeth A. Lloyd, have questioned the logic of this theory and the quality of the experimental data used to back it. During menstruation the cervix stretches open slightly to allow the endometrium to be shed. This stretching is believed to be part of the cramping pain that many women experience. Evidence for this is given by the fact that some women's cramps subside or disappear after their first baby because the cervical opening has widened. During childbirth, contractions of the uterus will dilate the cervix up to 10cm in diameter to allow the child to pass through.

Cervical cancer

In humans the cervix is associated with cervical cancer, a particular form of cancer which is detectable by cytological study of epidermal cells removed from the cervix in a process known as the pap smear. Evidence now shows that those with exposure to HPV, or the Human Papilloma Virus are at increased risk for cervical cancer. This virus is related to the virus that causes warts.

Lymphatic Drainage

The lymphatic drainage of the cervix is along the uterine arteries and cardinal ligaments to the parametrial, external iliac, internal iliac, obturator, and presacral lymph nodes. From these pelvic lymph nodes, drainage then proceeds to the paraaortic lymph nodes.

See also


- WikiSaurus:cervix — the WikiSaurus list of synonyms and slang words for the cervix in many languages Category:Reproductive system Category:Gynecology ..

Sexual intercourse

:This article is about sexual intercourse in humans and its societal implications. For biological copulation in general, see copulation. copulation copulation copulation Sexual intercourse or coitus is the human form of copulation. The term sexual intercourse refers to a wider range of sexual activities than the term coitus, which only refers to male-female genital sex. See Human sexual behavior for a discussion of the broader sense of sexual intercourse and List of sexual positions for the wide variety of sexual activities that exist. See the terms frot for male-male genital sex and tribadism for female-female genital sex. Coitus may be preceded by foreplay which leads to sexual arousal of the partners, resulting in erection of the penis and natural lubrication of the vagina. To engage in sexual intercourse, the erect penis is inserted into the vagina and one or both of the partners move back and forth to repeatedly remove and reinsert the penis, usually without ever fully removing it. In this way, they stimulate themselves and each other usually until orgasm and ejaculation are achieved. A detailed description of the physiology of sexual arousal and orgasm can be found in the article Human sexual response cycle.

Sexual reproduction

Coitus is the basic reproductive method of humans. During ejaculation, which normally accompanies male orgasm, a series of muscular contractions delivers semen containing male gametes known as sperm cells or spermatozoa into the vault of the vagina. The subsequent route of the sperm from the vault of the vagina, is through the cervix and into the uterus, and thence into the fallopian tubes. Millions of sperm are present in each ejaculation, to increase the chances of one fertilizing an egg or ovum. Sperm cells can survive up to nine days in the female body. When a fertile ovum from the female is present in the fallopian tubes, the male gamete joins with the ovum resulting in fertilization and the formation of a new embryo. When a fertilized ovum reaches the uterus, it becomes implanted in the lining of the uterus known as endometrium and a pregnancy begins. Male-female genital sex should always be considered likely to result in pregnancy unless adequate contraceptive (birth control) measures are in force, or unless one (or both) of the partners is not fertile. For example a woman who has passed through the menopause cannot conceive, but can still participate in, and enjoy, intercourse. Where both participants are believed to be fertile pregnancy should still be considered as a possible outcome of intercourse since no birth control measure is 100% effective. Coitus interruptus, or withdrawal of the penis from the vagina just before the man's orgasm, typically has a high failure rate, but is reasonably effective when done correctly. Surgical sterilization (tubal ligation for women or vasectomy for men) is considered permanent birth control, although it can sometimes be reversed surgically, or, rarely, the body can repair itself. If both partners are fertile, abstinence from heterosexual sexual intercourse is the only 100% effective way to avoid pregnancy. Outercourse, and other sexual contact (such as mutual masturbation or oral sex), in which there is sexual activity without penis insertion, can be performed without resulting in pregnancy provided that semen does not come in contact with the vulva.

Sex evolving beyond reproduction

Humans, bonobos and notably dolphins are animals known to have non-reproduct sex, apparently for the sake of pleasure. All three animals have heterosex even when the female is not in estrus, that is, at a point in her reproductive cycle suitable for successful impregnation. Likewise, all three animals have homosex. In both humans and bonobos the female has hidden estrus, which does not evidence to the male whether she is fertile or not, to ensure sex at any time for social reasons rather than reproductive ones. Indeed, sex is often for social reasons and only occasionally for reproductive ones. Humans, bonobos and dolphins are all intelligent social animals, whose cooperative behavior proves far more successful than that of any individual alone. In these animals, the use of sex evolved beyond reproduction to serve additional social functions. Sex reinforces intimate social bonds between individuals to form larger social structures. The resulting cooperation encourages collective tasks that promote the group's survival.

Sexual drive

The urge of adult humans to have sexual intercourse is generally seen as being a physiological need similar to needs such as food, water and air. See, for example, Maslow's hierarchy of needs. At an emotional level sexual intercourse is often, though not always, the ultimate physical expression of feelings of romantic love between two humans (sometimes more). In many cultures, mutual romantic love often forms a formalized or informal partnership, a full sexual relationship within this partnership, procreation or adoption of children and parenting. Romantic partners can be differentsex or samesex. However sexual intercourse is also often decoupled from romantic love and/or from a wish for procreation. Casual sex often used to satisfy a physiological need is common although open to censure by some as being promiscuous and morally questionable. The sex industry is the commercialization of casual sex and prostitution may provide physiological satisfaction.

Sexual problems

Some males suffer from erectile dysfunction, or impotence, at least occasionally. For those whose impotence is caused by medical conditions, prescription drugs such as Viagra, Cialis, and Levitra are available. However, doctors caution against the unnecessary use of these drugs since they are accompanied by serious risks such as increased chance of heart attack. Also, as is too often the case, using a drug to counteract the symptom, impotence, masks the underlying problem causing the impotence, and does not fix the problem. A serious condition might be aggravated if left untreated. A more common sexual disorder in males is premature ejaculation (PE). Those afflicted with PE can perform intercourse for an average of 1.8 minutes before experiencing an orgasm. This compares with an average of 7.3 minutes for those not suffering from premature ejaculation. The U.S. Food and Drug Administration (FDA) is currently examining the drug dapoxetine to treat premature ejaculation. In clinical trials those with PE who took dapoxetine experienced intercourse three to four times longer before orgasm than without the drug. The American Urological Association (AUA) estimates that premature ejaculation could affect 27 percent to 34 percent of men in the United States. The AUA also estimates that 10 percent to 12 percent of men in the United States are affected by erectile dysfunction. Inability to achieve orgasm is called anorgasmia. It is much more common in women than men and usually needs attention from both partners over a long time span to solve. Many women, especially younger women with little sexual experience, have difficulty achieving orgasm. Whether a woman considers anorgasmia a problem or not is highly individual; the popular but dubious notion that both partners should achieve orgasm in "normal" intercourse may contribute to a woman's concern over anorgasmia. Vaginismus is involuntary tensing of the pelvic floor musculature, making coitus distressing or impossible. Dyspareunia is painful or uncomfortable intercourse; it can be due to a variety of reasons.

Sexual morality and legality

Various laws, moral rules, and taboos surround sexual intercourse. See sexual morality for a detailed discussion. Unlike some other sexual activities, sexual intercourse itself has rarely been made taboo on religious grounds or by government authorities. It is believed that all of the cultures that prohibited sexual intercourse entirely no longer exist, save the Shakers, a sect of Christianity which has very few adherents, although there are many communities within cultures that prohibit their members to engage in any form of sex, such as members of religious orders and the priesthood in the Roman Catholic Church and lamas in Buddhist monasteries. Within some ideologies, coitus has been considered the only "acceptable" sexual activity. Relatively strict designations of "appropriate" and "inappropriate" sexual intercourse have been almost universal in human societies. These have included prohibitions against specific positions, against intercourse among partners who are not married (this is called fornication) or at least one of whom is married, but not to each other (called adultery), against sexual intercourse with a close relative (called incest), and against intercourse during a woman’s menstrual period. Most countries have age of consent laws specifying the minimum legal age for engaging in sexual intercourse. Sexual intercourse with a person against his or her will, or without their informed legal consent, is called rape and is considered a serious crime in most cultures. Religions have often established standards and mores for sexual intercourse, usually encouraging monogamy and marriage. In the Christian faith, sex outside marriage is officially condemned with varying degrees of severity. This prohibition on sex solely for pleasure has led to the Roman Catholic Church’s highly controversial condemnation of contraception. See (for example) http://www.catholic.net/rcc/Periodicals/Faith/11-12-98/Morality2.html There is a good deal of controversy about the kind of relationship one should have with someone else before engaging in sexual intercourse. This controversy is beyond the scope of this article; interested readers are encouraged to read the articles on chastity, evolutionary psychology, and sexual morality.

See also


- Synonyms for sexual intercourse – the WikiSaurus list of synonyms and slang words for sexual intercourse in many languages
- Sexual slang
- Sexology
- Copulation
- Human sexual behavior
- Sexual orientation
  - Heterosexual
  - Bisexual
  - Homosexual
- Gender identification
  - Transgendered
- List of sex positions
  - Genital sex
    - Frot
    - Tribadism
  - Oral sex
  - Anal sex
  - Masturbation
- Sexual fetishism
  - BDSM
  - Pegging
  - Sex toys
- Seduction
- Sexual arousal
- Foreplay
- Reproduction
- Human sexual response cycle

External links


- [http://www.wsu.edu:8080/~taflinge/biosex2.html Biology of sexual intercourse]
- [http://www.nvsh.nl/Website_Engels/Texts/Sexual_Information/Basics/Skills_1.htm Dutch Society for Sexual Reform]
- [http://www.cps.gov.uk/legal/section7/index.html UK legal guidance for prosecutors concerning sexual acts]
- [http://www.abouthealth.com/parent_topic_dialogue.cfm?Parent_Excerpt_ID=23&Topic_Title=3 Resources for parents to talk about sexual intercourse to their children]
- [http://www.ppacca.org/site/pp.asp?c=kuJYJeO4F&b=139496 Planned Parenthood information on sexual intercourse]
- [http://www.healthcentral.com/mhc/top/003157.cfm Medical Resources related to sexual intercourse]
- [http://www.total-health-care.com/family-health/sexual-health.htm Sexual Health]
- [http://www.studentbmj.com/issues/00/01/papers/images/sex2.jpg Sexual intercourse diagram]
- [http://www.sex-project.com/ Sex Project - Information Guide and Forum Discussing All Aspects Of Sex and Relationships] Category:Biological reproduction Category:Human sexuality Category:Interpersonal relationships Category:Sex moves Category:Sex positions Category:Sexology Category:Sexual acts ko:성교 ja:性行為

1916

1916 (MCMXVI) is a leap year starting on Saturday (link will take you to calendar)

Events

January-February


- January 1 -The first successful blood transfusion using blood that had been stored and cooled. Impressionist Monet paints 'Water Lilies'.
- January 5 - Heavy rain - allegedly caused by rainmaker Charles Hatfield - begins; it will cause flooding around San Diego, California
- January 8 - Allied forces withdraw from Gallipoli
- January 13/14 - A heavy storm sweeps through the Zuiderzee in the Netherlands, causing extensive damage. This storm helped the Dutch parliament to decide to build the Afsluitdijk and build polders in the current IJsselmeer.
- January 17 - The Professional Golfers Association (PGA) is formed
- January 18 - A 611 gram chondrite type meteorite struck a house near Baxter, Stone County, Missouri.
- January 23 to 24 In Browning, Montana, the temperature drops from +6.7°C to -48.8°C (44°F to -56°F) in one day, the greatest change ever on record for a 24-hour period.
- January 24 - In Brushaber v. Union Pacific Railroad the Supreme Court of the United States declares the federal income tax void
- January 28 - Louis D. Brandeis becomes the first Jew appointed to the Supreme Court of the United States.
- January 29 - World War I: Paris is bombed by German zeppelins for the first time.
- February 2 - Blizzard in Victoria, British Columbia, Canada
- February 3 - Parliament buildings in Ottawa, Canada are burned down.
- February 9 - 6.00 PM - Tristan Tzara "founds" Dadaism (according to Hans Arp
- February 11 - Emma Goldman is arrested for lecturing on birth control.
- February 11 - Baltimore Symphony Orchestra presents its first concert
- February 21 - World War I: In France the Battle of Verdun begins.

March-June


- March 1 - Liberal British Columbia Premier Harlan Carey Brewster term in office ends
- March 6 - Sydney conservatorium of music in Australia accepts first students
- March 8-9 night - Mexican Revolution - Pancho Villa leads 1,500 Mexican raiders in an attack against Columbus, New Mexico, killing 17. Garrison of US 13th Cavalry Regiment fights back and drives them away.
- March 15 - President Woodrow Wilson sends 12,000 United States troops over the U.S.-Mexico border border to pursue Pancho Villa; 13th Cavalry regiment enters Mexican territory.
- March 16 - US 7th and 10th cavalry regiments under John J. Pershing crosses the border to join the hunt of Villa
- March 19 - First United States air combat mission in history as eight US planes take off in pursuit of Pancho Villa
- March 22 - Marriage of Edith Bratt and John Ronald Reuel Tolkien. They would serve as the inspiration for the fictional characters Lúthien and Beren.
- April 24 - April 30 - Easter Rising in Ireland
- April 27 - Battle of Hulluch in World War One, 47th Brigade, 16th Irish Division decimated in one of the most heavily-concentrated gas attacks of the war
- May 5 - United States Marines invade the Dominican Republic.
- May 20 - The Saturday Evening Post publishes its first cover with a Norman Rockwell painting ("Boy with Baby Carriage").
- May 21 - Sir Ernest Shackleton and two of his companions reach a whaling station to get help for the rest of the crew of Endurance.
- May 21 - Britain initiates daylight saving time.
- May 31 - June 1 - Battle of Jutland
- June 5 - Louis Brandeis is sworn in as a Justice of the United States Supreme Court.
- June 5 - HMS Hampshire sinks off the Orkneys, Scotland, with Lord Kitchener aboard
- June 15 - U.S. President Woodrow Wilson signs a bill incorporating the Boy Scouts of America. [http://www.scouting.org/factsheets/02-507.html]

July-August


- July 1 - November 18: More than 1 million soldiers die during The Battle of the Somme including 60,000 soldiers from the British Commonwealth on the first day. The United States is still unwilling to join in the war with Britain, Canada, Australia and the other commonwealth countries.
- July 1 through July 12, at least one shark mauled five swimmers along 80 miles of New Jersey coastline during the Jersey Shore Shark Attacks of 1916, resulting in four deaths and survival of one youth who required limb amputation. This event was the inspiration for author Peter Benchley, over half a century later, to write Jaws.
- July 15 - In Seattle, Washington, William Boeing incorporates Pacific Aero Products (later renamed Boeing).
- July 16 - Hellenic Holocaust: The entire Greek population of Sinope and the coastal region of the county of Kastanome is either exiled or killed.
- July 22 - In San Francisco, California, a bomb explodes on Market Street during a Preparedness Day parade killing 10 injuring 40. (Warren Billings and Tom Mooney are later wrongly convicted of it)
- July 29 - In Ontario, Canada, a lightning strike ignites a forest fire that destroys the towns of Cochrane and Matheson - 233 dead
- 2 August - World War I: Austrian sabotage causes the sinking of Italian battleship Leonardo da Vinci in Taranto.

October-December

Taranto.]]
- October 27 - Battle of Segale: Negus Mikael, marching on the Ethiopian capital in support of his son Emperor Iyasu, is defeated by Fitawrari Habte Giyorgis, securing the throne for Empress Zauditu.
- November 5 - Kingdom of Poland proclaimed by joined act of emperors of Germany and Austria
- November 7 - Woodrow Wilson defeats Charles E. Hughes in the U.S. presidential election.
- November 7 - Republican Jeannette Rankin of Montana becomes the first woman elected to the United States House of Representatives.
- November 13 - Prime Minister of Australia William Morris Hughes is expelled from the Labor Party over his support for conscription.
- November 18 - World War I: First Battle of the Somme ends - In France, British Expeditionary Force commander Douglas Haig calls off the battle which started on July 1, 1916.
- November 25 - Friedrich Adler shoots Karl Stürgh, prime minister of Austria
- November 30 - Hellenic Holocaust: According to the Austrian consul: "on 26 November Rafet Bey (Turkish Minister of the Interior) told me: "we must finish off the Greeks as we did with the Armenians … on 28 November.""
- December 12 - In the Dolomites, an avalanche buries 18,000 Austrian and Italian soldiers.
- December 30 - Humberto Gómez and his mercenaries seize Arauca in Colombia and declare Republic of Arauca. He proceeds to pillage the region before fleeing to Venezuela
- December 23 - World War I: Battle of Magdhaba - In the Sinai desert, Australian and New Zealand mounted troops capture the Turkish garrison.
- December 31 - The Hampton Terrace Hotel in North Augusta, South Carolina, one of the largest and most luxurious hotels in the nation at the time, burns to the ground.

Unknown dates


- Hipolito Irigoyen elected as the President of Argentina.
- Blaise Diagre, first black representative of Senegal in the French parliament
- Cours de linguistique générale by Ferdinand de Saussure is published.
- Summer Olympic Games in Berlin, Germany, are cancelled.
- Food is rationed in Germany.
- Ernst Rudin published his initial results on the genetics of schizophrenia.
- The Netherlands is hit by a North Sea storm that floods lowlands and kills 10.000 people.
- Woman's International Bowling Congress established in the US.
- Robert Baden-Powell founds Wolf Scouts in Britain, changed to Cub Scouts in the USA.
- Sopwith Camel aircraft is introduced to combat the German-built Fokker fighter aircraft.
- Louis Enricht claims he has a substitute for gasoline
- Gustav Holst composes The Planets, Opus 32
- Bray Studios created the Farmer Alfalfa series, the first of theTerrytoons.

Ongoing events


- World War I (1914-1918)
- Armenian Genocide (1915-1918)
- Mexican Revolution

Births

January-March


- January 3 - Betty Furness, American actress and consumer activist (d. 1994)
- January 7 - Paul Keres, Estonian chess player
- January 9 - Peter Twinn, English mathematician and World War II code-breaker (d. 2004)
- January 10 - Sune Bergström, Swedish biochemist, recipient of the Nobel Prize in Physiology or Medicine (d. 2004)
- January 12 - Pieter Willem Botha, President of South Africa
- January 22 - Henri Dutilleux, French composer
- February 9 - Tex Hughson, baseball player (d. 1993)
- February 11 - Joseph Alioto, Mayor of San Francisco (d. 1998)
- February 14 - Masaki Kobayashi, Japanese film director
- February 26 - Jackie Gleason, American comedian (d. 1987)
- February 29 - Dinah Shore, American singer (d. 1994)
- March 3 - Paul Halmos, Hungarian-born mathematician
- March 4 - Hans Eysenck, German-born psychologist (d. 1997)
- March 11 - Harold Wilson, Prime Minister of the United Kingdom (d. 1995)
- March 13 - John Aspinwall Roosevelt, American businessman and philanthropist (d. 1981)
- March 14 - Horton Foote, American writer
- March 15 - Harry James, American musician and band leader (d. 1983)
- March 17 - Ray Ellington, British singer (d. 1985)
- March 19 - Irving Wallace, American novelist (d. 1990)
- March 26 - Christian B. Anfinsen, American chemist, Christian B. Anfinsen laureate (d. 1995)
- March 29 - Eugene McCarthy, U.S. Senator from Minnesota (d. 2005)

April-June


- April 3 - Herb Caen, American journalist (d. 1997)
- April 5 - Gregory Peck, American actor (d. 2003)
- April 11 - Alberto Ginastera, Argentine composer (d. 1983)
- April 12 - Beverly Cleary, American author
- April 15 - Alfred S. Bloomingdale, American department store heir (d. 1982)
- April 22 - Yehudi Menuhin, American-born violinist (d. 1999)
- April 25 - R.J. Rushdoony, American founder of Christian Reconstructionism (d. 2001)
- April 28 - Ferruccio Lamborghini, Italian automobile manufacturer (d. 1993)
- April 30 - Claude Elwood Shannon, American information theorist (d. 2001)
- April 30 - Robert Shaw, American conductor (d. 1999)
- May 8 - João Havelange, Brazilian industrialist and football league president
- May 10 - Milton Babbitt, American composer
- May 11 - Camilo José Cela, Spanish writer, Nobel Prize laureate (d. 2002)
- May 20 - Trebisonda Valla, Italian athlete
- May 21 - Tinus Osendarp, Dutch runner (d. 2002)
- May 21 - Harold Robbins, American novelist (d. 1997)
- May 26 - Henriette Roosenburg, Dutch journalist (d. 1972)
- June 4 - Robert F. Furchgott, American chemist, recipient of the Nobel Prize in Physiology or Medicine
- June 8 - Francis Crick, English molecular biologist, recipient of the Nobel Prize in Physiology or Medicine (d. 2004)
- June 15 - Herbert Simon, American economist, Nobel Prize laureate (d. 2001)
- June 18 - Julio César Turbay Ayala, Colombian politician (d. 2005)
- June 23 - Hermann Gmeiner, Austrian educator (d. 1986)
- June 23 - Len Hutton, English cricketer (d. 1990)

July-December


- July 2 - Hans-Ulrich Rudel, German pilot (d. 1982)
- July 9 - Sir Edward Heath, Prime Minister of the United Kingdom (d. 2005)
- July 11 - Aleksandr Mikhailovich Prokhorov, Russian physicist, Nobel laureate (d. 2002)
- July 11 - Gough Whitlam, twenty-first Prime Minister of Australia
- July 14 - Natalia Ginzburg, Italian author (d. 1991)
- July 18 - L. Patrick Gray III, director of the American Federal Bureau of Investigation (d. 2005)
- July 22 - Marcel Cerdan, French boxer (d. 1949)
- July 31 - Bill Todman, American game show producer (d. 1979)
- August 25 - Frederick Chapman Robbins, American pediatrician and virologist, recipient of the Nobel Prize in Physiology or Medicine (d. 2003)
- August 27 - Martha Raye, American actress (d. 1994)
- September 13 - Roald Dahl, Welsh author (d. 1990)
- October 3 - James Herriot, veterinarian and author (d. 1995)
- October 4 - Vitaly Ginzburg, Russian physicist, Nobel laureate
- October 19 - Jean Dausset, French immunologist, recipient of the Nobel Prize in Physiology or Medicine
- October 19 - Emil Gilels, Ukrainian pianist (d. 1994)
- October 26 - François Mitterrand, President of France (d. 1996)
- October 30 - Leon Day, baseball player (d. 1995)
- November 1 - John C. Harkness, American architect
- November 4 - Walter Cronkite, American television journalist
- November 5 - Jim Tabor, baseball player
- November 10 - Louis le Brocquy, Irish painter
- November 16 - Daws Butler, American voice actor
- November 24 - Forrest J. Ackerman, American writer
- November 27 - Chick Hearn, American basketball announcer (d. 2002)
- November 28 - Mary Lilian Baels, queen of Léopold III of the Belgians (d. 2002)
- November 29 - Fran Ryan, American actress (d. 2000)
- December 9 - Kirk Douglas, American actor
- December 11 - Dámaso Pérez Prado, Cuban musician (d. 1989)
- December 15 - Maurice Wilkins, New Zealand-born physicist, recipient of the Nobel Prize in Physiology or Medicine (d. 2004)
- December 19 - Elisabeth Noelle-Neumann, German political scientist
- Jack Agazarian, English World War II spy (d. 1945)

Deaths


- February 6 - Rubén Darío, Nicaraguan writer (b. 1867)
- February 12 - Richard Dedekind, German mathematician (b. 1831)
- February 19 - Ernst Mach, Austrian physicist and philosopher (b. 1838)
- February 20 - Klas Pontus Arnoldson, Swedish writer and pacifist, recipient of the