EJACULATION

EJACULATION:


EJACULATION:
This article is about male ejaculation. For female ejaculation, see Female ejaculation. For the grammatical term, see Ejaculation (grammar).

Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm. It is usually the result of sexual stimulation, which may include prostate stimulation. Rarely, it is due to prostatic disease. Ejaculation may occur spontaneously during sleep (a nocturnal emission). Anejaculation is the condition of being unable to ejaculate.

The process of ejaculation is an intense sensation, part of orgasm (French "la petite mort" - the little death), which can be immensely pleasureable and satisfying. Each spurt is associated with a wave of sexual pleasure, especially in the penis and loins. The first and second convulsions are usually the most intense in sensation, and produce the greatest quantity of semen. Thereafter, each contraction is associated with a diminishing volume of semen and a milder wave of pleasure. During sexual intercourse or masturbation, most males will find it difficult to resist the psychological temptation to continue the stimulation of the penis to the point of ejaculation once the feeling of orgasm becomes imminent.

Ejaculation has two phases: emission and ejaculation proper. The emission phase of the ejaculatory reflex is under control of the sympathetic nervous system, while the ejaculatory phase is under control of a spinal reflex at the level of the spinal nerves S2-4 via the pudendal nerve. During emission, the two ducts known as vas deferens contract to propel sperm from the epididymis where it was stored up to the ampullae at the top end of the vas deferens. The beginning of emission is typically experienced as a "point of no return," also known as point of ejaculatory inevitability. The sperm then passes through the ejaculatory ducts and is mixed with fluids from the seminal vesicles, the prostate, and the bulbourethral glands to form the semen, or ejaculate. During ejaculation proper, the semen is ejected through the urethra with rhythmic contractions.[1]

DEMONSTRATION OF EJACULATION PROPER:
These rhythmic contractions are part of the male orgasm. The typical male orgasm lasts about 17 seconds but can vary from a few seconds up to about a minute. After the start of orgasm, pulses of semen begin to flow from the urethra, reach a peak discharge and then diminish in flow. The typical orgasm consists of 10 to 15 contractions. The rate of contractions gradually slows during the orgasm. Initial contractions occur at an average interval of 0.6 seconds with an increasing increment of 0.1 second per contraction. Contractions of most men procede at regular rhythmic intervals for the duration of the orgasm. Many men also experience additional irregular contractions at the conclusion of the orgasm.[2]

Semen begins to spurt from the penis during the first or second contraction of orgasm. For most men the first spurt occurs during the second contraction. A small study of seven men found the initial spurt occurring on the first contraction for 2 men and occurring on the second contraction for 5 men. This same study showed between 26 and 60 percent of the contractions during orgasm were accompanied by a spurt of semen.[3]

The force and amount of ejaculate vary widely from male to male. A normal ejaculation may contain anywhere from 1.5 to 5 milliliters.[4]Boys that are going through puberty might produce a very small amount of semen, clear semen, or none at all. Adult ejaculate volume is affected by the amount of time that has passed since the previous ejaculation. Larger ejaculate volumes are seen with greater durations of abstinence. However, a recent Australian study has suggested a positive correlation between prostate cancer and infrequent ejaculation and/or prostate milking, which performs essentially the same function. That is, frequent masturbation appears to reduce the risk of prostate cancer. Frequent ejaculation is more easily obtained and sustained over time with the aid of masturbation and it is these ejaculations which are important, not the mechanism. [5] Also, the duration of the stimulation leading up to the ejaculation can affect the volume. Abnormally low volume is known as hypospermia, though it is normal for the amount of ejaculate to diminish with age.

The number of sperm in an ejaculation also varies widely, depending on many factors, including the recentness of last ejaculation, the average warmth of the testicles, the degree and length of time of sexual excitement prior to ejaculation, the age, testosterone level, the nutrition and especially hydration and the total volume of seminal fluid. An unusually low sperm count, not the same as low semen volume, is known as oligospermia, and the absence of any sperm from the ejaculate is termed azoospermia.

Most men experience a lag time between the ability to ejaculate consecutively, and this lag time varies among men. Age also affects the recovery time; younger men typically recover faster than older men. During this refractory period it is difficult or impossible to attain an erection, because the sympathetic nervous system counteracts the effects of the parasympathetic nervous system.

There are wide variations in how long sexual stimulation can last before ejaculation occurs.

When a man ejaculates before he wants to it is called premature ejaculation. If a man is unable to ejaculate in a timely manner after prolonged sexual stimulation, in spite of his desire to do so, it is called delayed ejaculation or anorgasmia. An orgasm that is not accompanied by ejaculation is known as a dry orgasm.

CENTRAL NERVOUS SYSTEM CONTROL:
To map the neuronal activation of the brain during the ejaculatory response, researchers have studied the expression of c-fos, a proto-oncogene expressed in neurons in response to stimulation by hormones and neurotransmitters [6] Expression of c-fos in the following areas have been observed: [7],[8]

medial preoptic area (MPOA) // lateral septum, bed nucleus of the stria terminalis // paraventricular nucleus of the hypothalamus (PVN) // ventromedial hypothalamus, medial amygdala // ventral premammillary nuclei // ventral tegmentum // central tegmental field // mesencephalic central gray // peripeduncular nuclei // parvocellular subparafascicular nucleus (SPF) within the posterior thalamus

FERTILIZATION:
Normally, ejaculation is required for emission of sperm, which can fertilize a woman's egg and impregnate her. However, almost all men produce a small amount of pre-ejaculate fluid when their penis is erect and they are sexually stimulated, and this pre-ejaculate may contain some sperm which can also lead to pregnancy. For this reason, coitus interruptus may still lead to unwanted pregnancies for couples engaging in vaginal intercourse if other forms of birth control are not used as well.

EUPHEMISMS:
Because sexual topics are often an uncomfortable topic among peers, a huge variety of euphemisms and dysphemisms have been invented to describe ejaculation and semen. For a complete list of terms, see: "Sexual slang".

EJACULATION FACTS:
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Average energy in a tablespoon of semen: 2-7 kilocalories, 8-29 kilojoules
Average number of sperm cells in the ejaculate of a healthy man: 40 million to 600 million (avg. 250 million)
Distance sperm travels to fertilize an egg: 7.5-10 centimeters or 3-4 inches
Sperm lifespan: 2.5 months from development to ejaculation
Sperm lifespan after ejaculation: 30 seconds to 6 days depending on conditions

SEMEN:
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.


COMPOSITION OF HUMAN SEMEN:
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 CONTRIBUTIONOF SEMEN ARE AS FOLLOWS:

Gland Approximate % Description

testes 2-5%[1] Approximately 200- to 500-million spermatozoa
. 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 < 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

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 20x106 spermatozoa/ml or more, sperm count of 40x106 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

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. []

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.
Sexual stimulation is any stimulus that leads to sexual arousal or orgasm. The term often implies stimulation of the genitals but may also include stimulation of other areas of the body, stimulation of the senses (such as sight or hearing), and mental stimulation (such as that gotten from reading or fantasizing).

PHYSICAL SEXUAL STIMULATION:
Physical sexual stimulation usually consists of the touching of parts of the human body, especially erogenous zones. Masturbation is considered a type of sexual stimulation. Physiological reactions are usually triggered through sensitive nerves in these body parts which cause the release of pleasure-causing chemicals that act as mental rewards to pursue such stimulation. Arousal is usually the term used to describe such a physiological reaction. Physical sexual stimulation may also involve the touching of other people's body parts and may trigger similar physiological reactions.

MENTAL SEXUAL STIMOLATION
Mental sexual stimulation consists of any visual images, imagination, reading material, auditory stimulation that causes sexual stimulation and leads to arousal. The degree of sexual stimulation derived from any such activity depends upon the person and the circumstance. Pornography is considered to be the most prominent example of mental stimulation and the watching of pornographic material can lead to arousal in many people, especially for young men and boys in their teenage years

AROUSAL
The capability for arousal from sleep provides an organism with the energy, strength, and opportunity to become mobile and to direct its sensory organs to locate and ingest food, to procreate, and avoid predation or other potentially dangerous situations. The energy and strength of a mobile organism, and its sensory organs serve to protect an animal in its search for nutrition and in its ability to ingest it, thus ensuring its survival. These same factors also make possible its attempts to procreate, thus ensuring its success as an organism. The balance of sleep and wakefulness is essential to the survival and the success of every animal that sleeps.

NOCTURNAL EMISSION
"Wet Dream" and "Wet Dreams" redirect here. For other uses, see Wet Dream (disambiguation).
A nocturnal emission is an ejaculation of semen experienced during sleep. It is also called a "wet dream", an involuntary orgasm, or simply an orgasm during sleep.
Nocturnal emissions are most common during teenage and early adult years. However, nocturnal emissions may happen any time after puberty. They may or may not be accompanied by erotic dreams. It is possible to wake up during, or to simply sleep through, the ejaculation in what is sometimes called a "sex dream".

FREQUENCY
The frequency of nocturnal emissions is highly variable. Some men have experienced large numbers of nocturnal emissions as teenagers, while some men have never experienced one. 83 percent of men in the United States will eventually experience nocturnal emissions at some time in their lives.[1] Surveys in non-western countries where masturbation is culturally suppressed show 98 percent or more of the men eventually experience nocturnal emissions. [2] For males that have experienced nocturnal emissions the mean frequency ranges from 0.36 times per week for single 15 year old males to 0.18 times per week for 40 year old single males. For married males the mean ranges from 0.23 times per week for 19 year old married males to 0.15 times per week for 50 year old married males.[3]

Men who experience wet dreams more (or less) frequently than others usually do not have any sort of disease or problem. Some have the dreams only at a certain age, while others have them throughout their lives following puberty. The frequency that one has nocturnal emissions has not been conclusively linked to one's frequency of masturbation. Widely-known sex researcher Alfred Kinsey found "There may be some correlation between the frequencies of masturbation and the frequencies of nocturnal dreams. In general the males who have the highest frequencies of nocturnal emissions may have somewhat lower rates of masturbation. Some of these males credit the frequent emissions to the fact that they do not masturbate; but it is just as likely that the reverse relationship is true, namely, that they do not masturbate because they have frequent emissions."[4] For women the correlation is also short of conclusive "According to Kinsey's findings, women who suddenly lost the opportunity for several coital orgasms per week had only a few more orgasms in their sleep per year."[5]

One factor that can affect the number of nocturnal emissions a person has is whether they take testosterone-based drugs. In a 1998 study, the number of boys reporting nocturnal emissions drastically increased as their testosterone doses were increased, from 17% of subjects with no treatment to 90% of subjects at a high dose.[6]

During puberty, 13 percent of males experience their first ejaculation as a result of a nocturnal emission.[7] Kinsey found that males experiencing their first ejaculation through a nocturnal emission were older than those experiencing their first ejaculation by means of masturbation. The study indicates that such a first ejaculation resulting from a nocturnal emission was delayed a year or more from what would have been developmentally possible for such males through physical stimulation.[8]

Whereas an ejaculation normally terminates an erection, in the case of nocturnal emission, the subject often still has a functional erection afterward.[citation needed]

Although purported treatments to help prevent or diminish nocturnal emissions are available in abundance, none are known to have undergone any kind of rigorous experimentation or approval process such as that required by the Food and Drug Administration. Like the hiccups, there are a huge variety of "home remedies" with no scientific basis. Moreover, because no physical harm (beyond the inconvenience of the semen ejaculate) is caused by the event and it is not symptomatic of any underlying problem, it is generally considered inadvisable to undergo any sort of treatment except in cases of severe psychological trauma.

Involuntary orgasms can occur during waking hours in both sexes, but these are rare. The German word Pollution which does not have the same meaning as the English word "pollution", describes all these involuntary orgasms collectively.[9]

Regarding women, Kinsey found in 1953 that nearly 40 percent of the 5,628 women he interviewed experienced at least one nocturnal orgasm (orgasm during sleep), or "wet dream," by the time they were forty-five years old. A smaller study published in the Journal of Sex Research in 1986 found that 85 percent of the women who had experienced nocturnal orgasms had done so by the age of twenty-one, some even before they turned thirteen. In addition, women who have orgasms during sleep usually have them several times a year. Dr. Kinsey and his colleagues defined female nocturnal orgasm as sexual arousal during sleep that awakens one to perceive the experience of orgasm. Girls and women who don't have orgasms in their sleep, or who don't know whether or not they've had them, are perfectly normal. It may be easier for men to identify their wet dreams because of the "ejaculatory evidence." Vaginal secretions could be a sign of sexual arousal without orgasm.

ORGASM:
Orgasm is the conclusion of the plateau phase of the sexual response cycle, and is experienced by both males and females. Orgasm is controlled by our involuntary, or autonomic, nervous system [1]. It is accompanied by quick cycles of muscle contraction in the lower pelvic muscles, which surround the primary sexual organs and the anus. Orgasms are often associated with other involuntary actions, including vocalizations and muscular spasms in other areas of the body, and a generally euphoric sensation.

After orgasm, humans often feel tired and a need to rest. This was recently attributed to the release of prolactin.[2] Prolactin is a typical neuroendocrine response in depressed mood and irritation.[3] Ongoing research at the University Medical Center of Groningen, the Netherlands, studies brain events that accompany orgasm in men and women. Techniques used involve Positron Emission Tomography (PET) and fMRI. Male and female brains act almost the same during orgasm. Brain scans showed that large parts of the cerebral cortex temporarily reduced their activity.

FROM THE ERECTILE ORGAN:
Orgasm is achieved after direct stimulation of the penis or clitoris for a period of time. This stimulation can be caused by sexual intercourse, manual masturbation, oral sex, or a sensual vibrator. Any sexual stimulation of the penis or clitoris may eventually result in orgasm.

MULTIPLE ORGASM:
In some cases, women either do not have a refractory period or have a very short one and thus can experience a second orgasm soon after the first; some women can even follow this with additional consecutive orgasms. This is known as having multiple orgasms. After the initial orgasm, subsequent climaxes may be stronger or more pleasurable as the stimulation accumulates. Research shows that about 13% of women experience multiple orgasms[citation needed]; a larger number may be able to experience this with the proper stimulation (such as a vibrator) and frame of mind. However, for some women, their clitoris and nipples are very sensitive after climax, making additional stimulation initially painful. Taking deep, rapid breaths while continuing stimulation can assist in releasing this tension. [5]There are sensational reports of women having too many orgasms, including an unauthenticated claim that a young British woman has them constantly throughout the day, whenever she experiences the slightest vibration.

It is possible to have an orgasm without ejaculation (dry orgasm) or to ejaculate without reaching orgasm. Some men have reported having multiple consecutive orgasms, particularly without ejaculation. Males who experience dry orgasms can often produce multiple orgasms, as the need for a rest period, the refractory period, is reduced.[7] Some males are able to masturbate for hours at a time, achieving orgasm many times.[7] In recent years, a number of books have described various techniques to achieve multiple orgasms. Most multi-orgasmic men (and their partners) report that refraining from ejaculation results in a far more energetic post-orgasm state[citation needed]. Additionally, some men have also reported that this can produce more powerful ejaculatory orgasms when they choose to have them.

One technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating to prevent ejaculation. This can, however, lead to retrograde ejaculation, i.e. redirecting semen into the urinary bladder rather than through the urethra to the outside. It may also cause long term damage due to the pressure put on the nerves and blood vessels in the perineum. Men who have had prostate or bladder surgery, for whatever reason, may also experience dry orgasms because of retrograde ejaculation.

Other techniques are analogous to reports by multi-orgasmic women indicating that they must relax and "let go" to experience multiple orgasms. These techniques involve mental and physical controls over pre-ejaculatory vasocongestion and emissions, rather than ejaculatory contractions or forced retention as above. Sexual energy, though focused in the groin, can be channeled throughout the body. Anecdotally, successful implementation of these techniques can result in continuous or multiple "full-body" orgasms.[8]. Gentle digital stimulation of the prostate, seminal vesicles, and vas deferens provides erogenous pleasure that sustains intense emissions orgasms for some men. A dildo device (the Aneros) claims to stimulate the prostate and help men reach these kinds of orgasms.

Many men who began masturbation or other sexual activity prior to puberty report having been able to achieve multiple non-ejaculatory orgasms. Young male children are capable of having multiple orgasms due to the lack of refractory period until they reach their first ejaculation. In female children it is always possible, even after the onset of puberty. This capacity generally disappears in males with the subject's first ejaculation. Some evidence indicates that orgasms of men before puberty are qualitatively similar to the "normal" female experience of orgasm, suggesting that hormonal changes during puberty have a strong influence on the character of male orgasm.[9]

Internet rumors and a few scientific studies have pointed to the hormone prolactin as the likely cause of male refractory period. Because of this, there is currently an experimental interest in drugs which inhibit prolactin, such as Dostinex (also known as Cabeser, or Cabergoline). Anecdotal reports on Dostinex suggest it may be able to eliminate the refractory period altogether, allowing men to experience multiple ejaculatory orgasms in rapid succession. At least one scientific study supports these claims.[10] Dostinex is a hormone-altering drug and has many potential side effects. It has not been approved for treating sexual dysfunction. Another possible reason may be an increased infusion of the hormone oxytocin. Furthermore, it is believed that the amount by which oxytocin is increased may affect the length of each refractory period.

A scientific study to successfully document natural, fully ejaculatory, multiple orgasms in an adult man was conducted at Rutgers University in 1995. During the study, six fully ejaculatory orgasms were experienced in 36 minutes, with no apparent refractory period.[11] It can also be said that in some cases, the refractory period can be reduced or even eliminated through the course of puberty and on into adulthood. Later, P. Haake et al. observed a single male individual producing multiple orgasms without elevated prolactin response.[12]

SPONTENEOUS ORGASM:
Orgasm can be spontaneous, seeming to occur with no direct stimulation. Many people find this to be quite embarrassing but enjoyable. Occasionally, orgasm can occur during sexual dreams.

The first orgasm of this type was reported among people who had spinal cord injury (SCI). Although SCI very often leads to loss of certain sensations and altered self-perception, a person with this disturbance is not deprived of sexual feelings such as sexual arousal and erotic desires. Thus some individuals are able to initiate orgasm by mere mental stimulation. Some non-sexual activity may result in a spontaneous orgasm. The best example of such activity is a release of tension that unintentionally involves slight genital stimulation, like rubbing of the seat of the bicycle against genitals during riding, exercising, when pelvic muscles are tightened or when yawning.

It was also discovered that some anti-depressant drugs may provoke spontaneous climax as a side effect. There is no accurate data for how many patients who were on treatment with antidepressant drugs experienced spontaneous orgasm, as most were unwilling to accept the fact.

THE PROSTATIC STRUCTURE:
Some people are able to achieve orgasm through stimulation of the prostatic structure, which in men is the prostate and in women is the Skene's glands; in women the location of the Skenes's glands is often known as the g-spot, or Grafenberg Spot. Grafenberg being the physician who first identified the spot as having orgasmic potential. The stimulation can come from receptive intercourse, being fingered, fisted, or penetrated with a dildo. Orgasms of this kind can cause both male and female ejaculation. With sufficient stimulation, the prostatic structure can also be "milked." Providing that there is no simultaneous stimulation of the penis or clitoris, prostate milking can cause ejaculation without orgasm. When combined with penile stimulation, some men report that prostate stimulation increases the volume of their ejaculation. The prostatic structure produces a secretion that forms one of the components of ejaculate; in males sperm are transmitted from the ductus deferens into the male urethra via the ejaculatory ducts, which lie within the prostate gland, during orgasm.

Other categorizations of orgasm

Certain types and categorization of orgasm have become widely enough acknowledged to be discussed as distinctive forms of orgasm.

VAGINAL ORGASM
The concept of purely vaginal orgasm was first postulated by Sigmund Freud. In 1905, Freud argued that clitoral orgasm was an adolescent phenomenon, and upon reaching puberty the proper response of mature women changes to vaginal orgasms. While Freud provided no evidence for this basic assumption, the consequences of the theory were greatly elaborated, partly because many women felt inadequate when they could not achieve orgasm via vaginal intercourse that involved little or no clitoral stimulation. Freud's claims about this and many other biological subjects, were later largely proven false or based on supposition.

In 1966, Masters and Johnson published pivotal research about the phases of sexual stimulation. Their work included women and men, and unlike Alfred Kinsey earlier (in 1948 and 1953), tried to determine the physiological stages before and after orgasm.[14] One of the results was the promotion of the idea that vaginal and clitoral orgasms follow the same stages of physical response. Masters and Johnson also argued that clitoral stimulation is the primary source of orgasms.

Recent discoveries about the size of the clitoris - it extends inside the body, around the vagina[15] - complicate or may invalidate attempts to distinguish clitoral vs. vaginal orgasms. Recent anatomical research shows that there are nerves connecting intravaginal tissues and the clitoris[citation needed]. This, with the anatomical evidence that the internal part of the clitoris is a much larger organ than previously thought, could explain credible reports of orgasms in women who have undergone clitorectomy as part of so-called female circumcision (also called female genital mutilation). The link between the clitoris and the vagina is evidence that the clitoris is the 'seat' of the female orgasm and is far wider-spread than the visible part most people associate with it. But it is possible that some women have more extensive clitoral tissues and nerves than others, and so that some women can achieve orgasm only by direct stimulation of the external part of the clitoris

MASTURBATION:
Masturbation refers to sexual stimulation, especially of one's own genitals and often to the point of orgasm, which is performed manually, by other types of bodily contact (except for sexual intercourse), by use of objects or tools, or by some combination of these methods.[1] Masturbation is the most common form of autoeroticism, and the two words are often used as synonyms, although masturbation with a partner (mutual masturbation) is also common. Animal masturbation has been observed in many species, both in the wild and in captivity.

Origins
Masturbation exercises sexual functions to increase fertility during intercourse.

FEMALE:
Masturbation in females is a tool to regulate the conditions in the vagina, cervix and uterus, which is used to either increase or decrease the chances of conception from intercourse, depending on the timing of the masturbation. This timing is a subconscious decision. If she has intercourse with more than one male, it favors the chances of one or the other male's sperm reaching her egg.
During orgasm, the woman's cervix extends and retracts at each contraction (cervical tenting), and the opening to the cervix gapes open. If a seminal pool is still present in the vagina when she masturbates, a significant number of sperm will be sucked up into her cervix
She can also increase the acidity of the cervical mucus to provide protection against infections.

MALE:
The function of masturbation is to flush out old sperm with low motility from the male's genital tract. The next ejaculate contains more fresh sperm, which has higher chances of achieving conception during intercourse. If more than one male is having intercourse with a female, the sperm with the highest motility will compete more effectively.[4]

MASTURBATION TECHNIQUES:

Ways of masturbating common to members of both sexes include pressing or rubbing the genital area, either with the fingers or against an object such as a pillow; inserting fingers or an object into the anus (see anal masturbation); and stimulating the penis or vulva/clitoris with electric vibrators, which may also be inserted into the vagina or anus. Members of both sexes may also enjoy touching, rubbing, or pinching the nipples or other erogenous zones while masturbating. Both sexes sometimes use lubricating substances to intensify sensation.

Reading or viewing pornography, or sexual fantasy, are often common adjuncts to masturbation. Masturbation activities are often ritualised. Various fetishes and paraphilias can also play a part in the masturbation ritual. Some potentially harmful or fatal activities include autoerotic asphyxiation and self-bondage

Some people get sexual pleasure by inserting objects into the urethra [5] (The urethra is the tube through which urine and, in men, semen, flows.) If these objects are urethral sounds, the practice is known as "sounding."[6] Other objects such as ball point pens and thermometers may be used. This practice can cause injury and infection.[7]

Some people masturbate by using machines that simulate intercourse.

Some people may masturbate until they are close to orgasm, stop for a while to reduce excitement, and then resume masturbating. They may repeat this cycle multiple times. This "stop and go" method is practiced in order to achieve even stronger orgasms.

Rarely, people quit stimulation just before orgasm to retain a heightened energy that normally comes down after orgasm [8] due to the release of prolactin hormone. A hazard of this technique is pelvic congestion.

FEMALE:
Female masturbation techniques are quite numerous and much more varied than those of males. Techniques include stroking or rubbing of the vulva, especially the clitoris, with the index and/or middle fingers. Sometimes one or more fingers may be inserted into the vagina to repeatedly stroke the frontal wall of the vagina where the g-spot is located. This gives a sensation close to that of orgasm.[9] Masturbation aids such as a vibrator, dildo or Ben Wa balls can also be used to stimulate the vagina and clitoris. Many women caress their breasts or stimulate a nipple with the free hand, if these are receptive areas for sexual stimulation. Anal stimulation is also enjoyed by some.

Lubrication is sometimes used during masturbation, especially when penetration is involved, but this is by no means universal and many women find their natural lubrication sufficient — some even produce more lubricant alone than with a partner[citation needed], though the reasons for this seem to be primarily psychological.

A vibrating duck. By de-dramatising the vibrator, these toys have gained a wider acceptance.

Common positions include lying on back or face down, sitting, squatting, or even standing. While sitting in a bath a female may use a tap which thrusts water out at a high pressure aimed at the clitoris to provide an extremely pleasureable experience. Lying face down, one may straddle a pillow, the corner or edge of the bed, a partner's leg or some scrunched-up clothing and "hump" the vulva and clitoris against it. Standing up, the corner of an item of furniture, or even a washing machine, can be used to stimulate the clitoris through the labia and clothing. Havelock Ellis reported that turn-of-the-century seamstresses using treadle-operated sewing machines could achieve orgasm by sitting near the edge of their chairs.[10]

Some can reach orgasm merely by crossing their legs tightly and clenching the muscles in their legs, which creates pressure on the genitals. This can potentially be done in public without observers noticing. Some prefer to use only pressure, applied to the clitoris without direct contact, for example by pressing the palm or ball of the hand against underwear or other clothing.

A few women can orgasm spontaneously, after experiencing prior sexual arousal, due to intellectual stimulation alone, for instance listening to certain pieces of music. Often, these mental triggers have associations with previous instances of arousal and orgasm. Some women even claim to be able to orgasm spontaneously by force of will alone, but that ability, if it exists at all, may not strictly qualify as masturbation as no physical stimulus is involved.[11] Sex therapists will sometimes recommend that female patients take time to masturbate to orgasm, especially if they have not done so before.[12][13]

MALE
Male masturbation techniques are also influenced by a number of factors and personal preferences. Techniques may also differ between circumcised and uncircumcised males, as some techniques which may work for one can often be quite painful for the other.
The most common male masturbation technique is simply to hold the penis with a loose fist and then to move the hand up and down the shaft until orgasm and ejaculation take place. The speed of the hand motion will vary from male to male, although it is not uncommon for the speed to increase as ejaculation nears and for it to decrease during the ejaculation itself. When uncircumcised, stimulation of the penis in this way comes from the "pumping" of the foreskin. This gliding motion of the foreskin reduces friction. When circumcised, there is more direct contact between the hand and the glans, thus a personal lubricant is sometimes used to reduce friction.

Circumcised or not, men may rub or massage the glans, the rim of the glans, and the frenular delta.

Another technique is to place just the index finger and thumb around the penis about halfway along the shaft and move the skin up and down. A variation on this is to place the fingers and thumb on the penis as if playing a flute, and then shuttle them back and forth. A less common technique is to lie face down on a comfortable surface such as a mattress or pillow and rub the penis against it until orgasm is achieved. This technique may include the use of a simulacrum, or artificial vagina.

There are many other variations on male masturbation techniques. Some men place both hands directly on their penis during masturbation, while others use their free hand to fondle their testicles, nipples, or other parts of their body. Some may keep their hand stationary while pumping into it with pelvic thrusts in order to simulate the motions of sexual intercourse. Others may also use vibrators and other sexual devices more commonly associated with female masturbation. A few extremely flexible males can reach and stimulate their penis with their tongue or lips, and so perform autofellatio.

The prostate gland is one of the organs that contributes fluid to semen. As the prostate is touch-sensitive, some directly stimulate it using a well-lubricated finger or dildo inserted through the anus into the rectum. Stimulating the prostate from outside, via pressure on the perineum, can be pleasurable as well.

Ejaculation of semen is sometimes controlled by wearing a condom or by ejaculating onto a tissue or some other item. The individual male's ability to project his semen over a distance during ejaculation may also influence a male's behaviour at ejaculation, as some males on rare occasions have been known to ejaculate up to three meters (about ten feet). Most males rarely ejaculate much farther than a fraction of that distance however.

A somewhat controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating. This can, however, redirect semen into the bladder (referred to as retrograde ejaculation). If repeated on a regular basis, this technique could cause long term damage due to the pressure put on the nerves and blood vessels in the perineum. A dry orgasm is one that is reached while withholding ejaculation (or where retrograde ejaculation has taken place). Proponents of dry orgasm say that this is a learnable skill that can shorten the refractory period.

FREQUENCY:
Frequency of masturbation is determined by many factors, e.g., one's resistance to transient sexual tension, hormone levels influencing sexual arousal, sexual habits established during youth, peer influences, health, intensity of the ejaculatory urge,[14] and one's attitude to masturbation formed by culture.[15] Medical causes have also been associated with masturbation.[16][17][18]

"Forty-eight female college students were asked to complete a sexual attitudes questionnaire in which a frequency of masturbation scale was embedded. Twenty-four of the women (the experimental group) then individually viewed an explicit modeling film involving female masturbation. One month later, all subjects again completed the same questionnaire. Subjects in the experimental group also completed a questionnaire evaluating aspects of the film. Results indicated that the experimental group reported a significant increase in the average monthly frequency of masturbation, as compared to the control group. This same group, however, reported that the film had no effect on sexual attitudes or behavior."

It is thought that most people begin masturbating when reaching adolescence ,however many scholarly and clinical studies have been done on the matter, and many informal surveys have asked the question. A 2004 survey by Toronto magazine NOW was answered by an unspecified number of thousands.[19] The results show that an overwhelming majority of the males — 81% — began masturbating between the ages of 10 and 15. Among females, the same figure was a more modest majority of 55%. (Note that surveys on sexual practices are prone to self-selection bias.) It is not uncommon however to begin much earlier, and this is more frequent among females: 18% had begun by the time they turned 10, and 6% already by the time they turned 6. Being the main outlet of child sexuality, masturbation has been observed in very young children. In the book Human Sexuality: Diversity in Contemporary America, by Strong, Devault and Sayad, the authors point out, "A baby boy may laugh in his crib while playing with his erect penis (although he does not ejaculate). Baby girls sometimes move their bodies rhythmically, almost violently, appearing to experience orgasm."

According to a Canadian survey of Now magazine readers cited above, the frequency of masturbation declines after the age of 17. However, most males masturbate daily or even more frequently well into their 20s and sometimes far beyond. This decline is more drastic among females, and more gradual among males. While females aged 13–17 masturbated almost once a day on average (and almost as often as their male peers), adult women only masturbated 8–9 times a month, compared to the 18–22 among men. It is also apparent that masturbation frequency declines with age. Adolescent youths report being able to masturbate to ejaculation six or more times per day, while men in middle age report being hard pressed to ejaculate even once per day. The survey does not give a full demographic breakdown of respondents, however, and the sexual history of respondents to this poll, who are readers of an urban Toronto lifestyle magazine, may not extend to the general population.

This may be because females are less likely to masturbate while in a heterosexual relationship than men. Both sexes occasionally engage in this activity, however, even when in sexually active relationships. Popular belief asserts that individuals of either sex who are not in sexually active relationships tend to masturbate more frequently than those who are; however, much of the time this is not true as masturbation alone or with a partner is often a feature of a relationship. Contrary to conventional wisdom, several studies actually reveal a positive correlation between the frequency of masturbation and the frequency of intercourse as well as the number multiple sex partners. One study reported a significantly higher rate of masturbation in gay men and women who were in a relationship. [20] [21] [22] [23]
For both males and females, masturbation is a way to relieve stress, anxiety and even boredom. For many with compressed schedules or frequent travel, regular masturbation enables them to maintain sexual output and performance for when opportunity eventually knocks.

Other cultures have rites of passage into manhood that culminate in the first ejaculation of a male, usually by the hands of a tribal elder. In some tribes such as the Agta, Philippines, stimulation of the genitals is encouraged from an early age.[25] Upon puberty, the young male is then paired off with a "wise elder" or "witch doctor" who uses masturbation to build his ability to ejaculate in preparation for a ceremony. The ceremony culminates in a public ejaculation before a celebration. The ejaculate is saved in a wad of animal skin and worn later to help conceive children. In this and other tribes, the measure of manhood is actually associated more with the amount of ejaculate and his need than penis size. Frequent ejaculation through masturbation from an early age fosters frequent ejaculation well into adulthood. [26]

Masturbation is becoming accepted as a healthy practice and safe method for sharing pleasure without the strings. It is socially accepted and even celebrated in certain circles. Group masturbation events can be found online in just about any state. Masturbation marathons are yearly events and are occurring across the globe from the U.S. to the UK. These events provide a supportive environment where masturbation can be performed openly among young and old without embarrassment. Participants talk openly with onlookers while masturbating to share techniques and describe their pleasure.[27] [28]





HEALTH AND PSYCOLOGICAL EFFECT

BENEFITS

It is held in many mental health circles that masturbation can relieve depression, stress and lead to a higher sense of self-worth (Hurlbert & Whittaker, 1991). Masturbation can also be particularly useful in relationships where one partner wants more sex than the other — in which case masturbation provides a balancing effect and thus a more harmonious relationship.[citation needed]

In 2003, an Australian research team led by Graham Giles of The Cancer Council Australia [2] concluded that frequent masturbation by males appears to help prevent the development of prostate cancer. The study also indicated that this would be more helpful than ejaculation through sexual intercourse because intercourse can transmit diseases that may increase the risk of cancer instead. Also, frequent ejaculation is more easily obtained and sustained over time with the aid of masturbation.

Masturbation is also seen as a sexual technique that protects individuals from the risk of contracting sexually transmitted diseases. Support for such a view, and for making it part of the American sex education curriculum, led to the dismissal of US Surgeon General Joycelyn Elders during the Clinton administration.

Many people see masturbation as an effective, natural cure for insomnia. Sexual climax, from masturbation or otherwise, leaves one in a relaxed and contented state. This is frequently followed closely by drowsiness and sleep - particularly when one masturbates in bed.[citation needed]

Some people actually consider masturbation as a cardiovascular workout.[29] And while doctors have no proof of this actually being true, those suffering from cardiovascular disorders (particularly those recovering from myocardial infarction, or heart attacks) should resume physical activity (including sexual intercourse and masturbation) gradually and with the frequency and rigor which their physical status will allow. Some doctors will advise those recovering from heart attacks to resume sexual activity (solitary or with a partner) when one is able to climb two flights of stairs without experiencing shortness of breath or chest pain.[citation needed]

Blood pressure
A small study has shown that a test group which only had intercourse experienced, as a whole, lower blood pressure in stressful situations than those who had intercourse but also had masturbated for one or more days.