An orgasm (sexual climax) is the conclusion of the plateau phase of sexual response cycle, and may be experienced by both males and females. Orgasm is characterized by intense physical pleasure, controlled by the 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 muscular spasms in other areas of the body, a general euphoric sensation and, frequently, vocalizations.
The moments after orgasm are often a relaxing experience, which is attributed to the release of prolactin. Male and female brains demonstrate similar changes during orgasm, with brain scans showing a temporary reduction in the activity of large parts of the cerebral cortex.
Achieving orgasm
One of the main ways of achieving orgasm is by direct or indirect stimulation of the penis or clitoris. Such stimulation can come from a variety of activities, including but not limited to sexual intercourse, manual masturbation, anal sex, oral sex, non-penetrative sex, a sensual vibrator, or an erotic electrostimulation. Orgasm may also be achieved by stimulation of the nipples, uterus, or other erogenous zones. In the absence of physical stimulation, orgasm can be from psychological arousal alone, or during dreaming (a nocturnal emission or "wet dream" in males).
Important in sexual stimulation are internal glands, called the Skene's glands in women and the prostate in men, two homologous structures. In common use, the term G-spot refers to these areas.
The stimulation can come from receptive intercourse, fingering, fisting, or penetration with a dildo or other sex toy.
With sufficient stimulation, the prostatic structure can also be "milked." Providing that there is no simultaneous stimulation of the penis, prostate milking can cause ejaculation without orgasm. When combined with penile stimulation, some men report that prostate stimulation increases the volume of their ejaculation.
Female orgasmDiscussions of female orgasm are complicated by the fact that, perhaps artificially, orgasm in women has sometimes been labelled as two different things: the clitoral orgasm and the vaginal orgasm.
The concept of vaginal orgasm as a separate phenomenon was first postulated by Sigmund Freud. In 1905, Freud stated that clitoral orgasm was purely an adolescent phenomenon, and upon reaching puberty the proper response of mature women was a change-over to vaginal orgasms, meaning orgasms without any clitoral stimulation. While Freud provided no evidence for this basic assumption, the consequences of this theory were considerable. Many women felt inadequate when they could not achieve orgasm via vaginal intercourse alone, involving little or no clitoral stimulation.
Anal stimulation
An "anal orgasm" is an orgasm brought on by anal stimulation, such as from anal sex, an inserted finger, or a sex toy. Anecdotal evidence suggests that some women experience anal orgasm as qualitatively different from clitoral or vaginal orgasm, though for many others the distinction is less clear.
In both sexes, pleasure can be derived from the nerve endings around the anus and the anus itself. Hence, anal-oral contact can still be pleasurable without stimulation of the clitoris. Jack Morin has claimed that anal orgasm has nothing to do with the prostate orgasm, although the two are often confused.
Breast and nipple stimulation
A "breast orgasm" is a female orgasm that is triggered from the stimulation of a woman's breast. Not all women experience this effect when the breasts are stimulated; however, some women claim that the stimulation of the breast area during sexual intercourse and foreplay, or just the simple act of having their breasts fondled, has created mild to intense orgasms.
Medical aspects of orgasm (Physiological responses)
In men
During orgasm, a human male experiences rapid, rhythmic contractions of the anal sphincter, the prostate, and the muscles of the penis. The sperm are transmitted up the vas deferens from the testicles, into the prostate gland as well as through the seminal vesicles to produce what is known as semen. The prostate produces a secretion that forms one of the components of ejaculate. Contraction of the sphincter and prostate force stored semen to be expelled through the penis's urethral opening. The process takes from three to ten seconds, and produces a warm and highly pleasurable feeling.
Normally, as a man ages, the amount of semen he ejaculates diminishes, and so does the duration of orgasms. This does not normally affect the intensity of pleasure, but merely shortens the duration.
After ejaculation, a refractory period usually occurs, during which a man cannot achieve another orgasm. This can last anywhere from less than a minute to several hours, depending on age and other individual factors.
Sensation
As a man nears orgasm during stimulation of the penis, he feels an intense and highly pleasurable pulsating sensation of neuromuscular euphoria. These pulses begin with a throb of the anal sphincter and travel to the tip of the penis. They eventually increase in speed and intensity as the orgasm approaches, until a final "plateau" of pleasure sustained for several seconds, the orgasm.
During orgasm, semen is usually ejaculated and may continue to be ejaculated for a few seconds after the euphoric sensation gradually tapers off. It is believed that the exact feeling of "orgasm" varies from one man to another,[33] but most male human beings agree that it is highly pleasurable.
In women
A typical woman's orgasm lasts much longer than that of a man.It is preceded by erection of the clitoris and moistening of the opening of the vagina. Some women exhibit a sex flush, a reddening of the skin over much of the body due to increased blood flow to the skin. As a woman nears orgasm, the clitoral glans moves inward under the clitoral hood, and the labia minora (inner lips) become darker. As orgasm becomes imminent, the outer third of the vagina tightens and narrows, while overall the vagina lengthens and dilates and also becomes congested from engorged soft tissue. The uterus then experiences muscular contractions. A woman experiences full orgasm when her uterus, vagina, anus, and pelvic muscles undergo a series of rhythmic contractions. Most women find these contractions very pleasurable. Recently, researchers from the University Medical Center of Groningen, the Netherlands, showed that it is possible to objectively recognize orgasms just by the specific frequencies of these contractions. After orgasm, the clitoris re-emerges from under the clitoral hood, and returns to its normal size, typically within ten minutes.
Orgasm and health
Orgasm, and indeed sex as a whole, are physical activities that can require exertion of many major bodily systems. A 1997 study in the British Medical Journal[37] based upon 918 men age 45-59 found that after a ten year follow-up, men who had fewer orgasms were twice as likely to die of any cause as those having two or more orgasms a week. A follow-up in 2001 which focused more specifically on cardiovascular health found that having sex three or more times a week was associated with a 50% reduction in the risk of heart attack or stroke. (Note that as a rule, correlation does not imply causation).
Drugs and orgasm
Certain drugs have been reported to have enhancing effects on orgasm. Nitrite inhalants are used by both men and women to enhance orgasm.
Cocaine & mushrooms also increases sexual desire while delaying orgasm. Both male and female users of stimulants, sometimes report heightened sexual pleasure. Throughout history, recreational drugs have been used to enhance orgasm, but due to lack of research (or government-mandated research restrictions), may be unreliable or have hazardous side effects. Anecdotal evidence suggests that women have enhanced orgasms with sildenafil.