Orgasm (from Greek ὀργασμός, orgasmos; "excitement, swelling") or sexual climax is the sudden discharge of accumulated sexual excitement during the sexual response cycle, resulting in rhythmic, involuntary muscular contractions in the pelvic region characterized by sexual pleasure. Experienced by males and females, orgasms are controlled by the involuntary or autonomic nervous system. They are usually associated with involuntary actions, including muscular spasms in multiple areas of the body, a general euphoric sensation and, frequently, body movements and vocalizations. The period after orgasm (known as the refractory period) is typically a relaxing experience, attributed to the release of the neurohormones oxytocin and prolactin as well as endorphins (or "endogenous morphine").Human orgasms usually result from physical sexual stimulation of the penis in males (typically accompanying ejaculation) and of the clitoris in females. Sexual stimulation can be by self-practice (masturbation) or with a sex partner (penetrative sex, non-penetrative sex, or other sexual activity). The health effects surrounding the human orgasm are diverse. There are many physiological responses during sexual activity, including a relaxed state created by prolactin, as well as changes in the central nervous system such as a temporary decrease in the metabolic activity of large parts of the cerebral cortex while there is no change or increased metabolic activity in the limbic (i.e., "bordering") areas of the brain. There is also a wide range of sexual dysfunctions, such as anorgasmia.
For some women, the clitoris is very sensitive after climax, making additional stimulation initially painful.Masters and Johnson argued that all women are potentially multiply orgasmic, but that multiply orgasmic men are rare, and stated that "the female is capable of rapid return to orgasm immediately following an orgasmic experience, if re-stimulated before tensions have dropped below plateau phase response levels". Though generally reported that women do not experience a refractory period and thus can experience an additional orgasm, or multiple orgasms, soon after the first one, some sources state that both men and women experience a refractory period because women may also experience a period after orgasm in which further sexual stimulation does not produce excitement. After the initial orgasm, subsequent orgasms for women may be stronger or more pleasurable as the stimulation accumulates. Clitoral and vaginal categories
Discussions of female orgasm are complicated by orgasms in women typically being divided into two categories: clitoral orgasm and vaginal (or G-spot) orgasm. In 1973, Irving Singer theorized that there are three types of female orgasms; he categorized these as vulval, uterine, and blended, but because he was a philosopher, "these categories were generated from descriptions of orgasm in literature rather than laboratory studies". In 1982, Ladas, Whipple and Perry also proposed three categories: the tenting type (derived from clitoral stimulation), the A-frame type (derived from G-spot stimulation), and the blended type (derived from clitoral and G-spot stimulation).