During the 1950s and 1960s, William H. Masters and Virginia E. Johnson conducted many important studies within the field of human sexuality. In 1966, in their book Human Sexual Response, they detailed four stages of physiological changes of humans during sexual stimulation. These phases, in order of their occurrence, are the excitement phase, plateau phase, orgasmic phase, and resolution phase. Together, they make up the human sexual response cycle. This does not cite any references or sources. ... The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... Time magazine, May 25, 1970 The Masters and Johnson research team, made up of William Masters and Virginia E. Johnson, pioneered research into the nature of human sexual response and the diagnosis and treatment of sexual disorders and dysfunctions from 1957 until the 1990s. ... This article is about human sexual perceptions. ... Year 1966 (MCMLXVI) was a common year starting on Saturday (link will display full calendar) of the 1966 Gregorian calendar. ...

Excitement phase

The excitement phase (also known as the arousal phase) is the first stage of the human sexual response cycle. It occurs as the result of any erotic physical or mental stimulation, such as kissing, petting, or viewing erotic images, that lead to sexual arousal. During the excitement stage, the body prepares for coitus, or sexual intercourse, in the plateau phase. Eroticism is an aesthetic focused on sexual desire, especially the feelings of anticipation of sexual activity. ... Stimulation is the irritating action of various agents (stimuli) on muscles, nerves, or a sensory end organ, by which activity is evoked; especially, the nervous impulse produced by various agents on nerves, or a sensory end organ, by which the part connected with the nerve is thrown into a state... For other uses, see Kiss (disambiguation). ... Petting is the act of a human stroking an animals fur (mostly cats and dogs) for mutual pleasure. ... It has been suggested that this article or section be merged into image (disambiguation). ... Turn on redirects here. ... A pair of lions copulating in the Maasai Mara, Kenya. ... It has been suggested that Duration of sexual intercourse be merged into this article or section. ...

Excitement in Both Sexes

An exaggerated male erection from Pompeii

Among both sexes, the excitement phase results in an increase in heart rate (tachycardia), an increase in breathing rate, and a rise in blood pressure. An erection of the nipples, especially upon direct stimulation, will occur in nearly all females^{[citation needed]} and approximately 60% of males^{[citation needed]}. Vasocongestion of the skin, commonly referred to as the sex flush, will occur in approximately 50-75%^{[citation needed]} of females and 25% of males^{[citation needed]}. The sex flush tends to occur more often under warmer conditions and may not appear at all under cooler temperatures. It has also been commonly observed that the marked degree of the sex flush can predict the intensity of orgasm to follow. Image File history File links Download high resolution version (864x1152, 142 KB)Fresco of Priapus, Casa Dei Vettii, Pompeii File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Download high resolution version (864x1152, 142 KB)Fresco of Priapus, Casa Dei Vettii, Pompeii File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The shield and spear of the Roman god Mars, which is also the alchemical symbol for iron, represents the male sex. ... Erected penis This article discusses human physiological erection. ... For other uses, see Pompeii (disambiguation). ... This article or section does not cite any references or sources. ... A sphygmomanometer, a device used for measuring arterial pressure. ... Erected penis This article discusses human physiological erection. ... This article is about anatomical structure. ... Commonly referred to as the sex flush, vasocongestion (increased blood flow) of the skin can occur during all four phases of the human sexual response cycle. ...

An increase in muscle tone (myotonia) of certain muscle groups, occurring voluntarily and involuntarily, begins during this phase among both sexes. Also, the external anal sphincter may contract randomly upon contact (or later during orgasm without contact). Myotonia is a neuromuscular disorder characterized by the slow relaxation of the muscles after voluntary contraction or electrical stimulation. ... Male Anatomy The anus, in anatomy, is the external opening of the rectum. ... The anal wink or anocutaneous reflex is the reflexive contraction of the external anal sphincter upon stroking of the skin around the anus or the head of the penis. ... // An orgasm (sexual climax) is the conclusion of the plateau phase of the sexual response cycle, and is experienced by both males and females. ...

During the female sex flush, pinkish spots develop under the breasts, then spread to the breasts, torso, face, hands, soles of the feet, and possibly over the entire body. Vasocongestion is also responsible for the darkening of the clitoris and the walls of the vagina during sexual arousal. During the male sex flush, the coloration of the skin develops less consistently than in the female, but typically starts with the epigastrium (upper abdomen), spreads across the chest, then continues to the neck, face, forehead, back, and sometimes, shoulders and forearms.

The sex flush typically disappears soon after orgasm occurs, but this may take up to two hours or so, and sometimes, intense sweating will occur simultaneously. The flush usually diminishes in reverse of which it appeared.

Excitement in Males

In males, the beginning of the excitement phase is observed when the penis becomes partially erect, often after only a few seconds of erotic stimulation. The erection may be partially lost and regained repeatedly during an extended excitement phase. Both testicles become drawn upward toward the perineum, notably in circumcised males where less skin is available to accommodate the erection. Also, the scrotum can tense and thicken during the erection process. The penis (plural penises, penes) is an external male sexual organ. ... Erected penis This article discusses human physiological erection. ... Human male anatomy The testicles, known medically as testes (singular testis), are the male generative glands in animals. ... In human anatomy, the perineum also known in slang as taint, grundle, chode, or gooch is generally defined as the surface region in both males and females between the pubic symphysis and the coccyx. ... This article is about male circumcision. ... In some male mammals, the scrotum is a protuberance of skin and muscle containing the testicles. ...

Excitement in Females

In females, venous patterns across the breasts become more visible and the breasts very slightly increase in size, which becomes more observable if lying on the back. The labia majora become flatter, thinner, and raise upwards and outwards in nulliparous women (those who have not given birth)^{[citation needed]}. In parous women (those that have given birth), they may increase two or threefold in size^{[citation needed]}. The labia minora may increase in size and may protrude from the labia majora, depending on the size they are in a normal, relaxed state. The clitoral glans becomes tumescent, or swollen, like the glans of the penis. After only seconds of stimulation, vaginal lubrication is produced by the vasocongestion of the vaginal walls. They darken in color and become smoother than normal. Also, the uterus elevates, more vertically as time passes, and the inner two-thirds of the vagina expand, usually a total of 7 to 10 cm^{[citation needed]}. Parts of a vulva The external genital organs of the female are collectively known as the vulva (also sometimes called the pudenda). ... In medicine, parity is a technical term that refers to the number of times a woman has given birth. ... The labia minora (nymphae) are two small cutaneous folds, situated between the labia majora, and extending from the clitoris obliquely downward, lateralward, and backward for about 4 cm. ... The Clitoral Glans is an external portion of the clitoris. ... Tumescence is the quality or state of being tumescent or swollen. ... glans Well known Street Art artist from Copenhagen, Denmark. ... The Bartholins glands (also called Bartholin glands or greater vestibular glands) are two glands located slightly below and to the left and right of the opening of the vagina in women. ... This article is about female reproductive anatomy. ... The vagina, (from Latin, literally 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. ...

Plateau phase

The plateau phase is the period of sexual excitement prior to orgasm. // An orgasm (sexual climax) is the conclusion of the plateau phase of the sexual response cycle, and is experienced by both males and females. ...

The plateau phase is the second phase of the sexual cycle, after the excitement phase. Further increases in circulation and heart rate occur in both sexes, sexual pleasure increases with increased stimulation, muscle tension increases further.

During this phase, the male urinary bladder closes (so as to prevent urine from mixing with semen) and muscles at the base of the penis begin a steady rhythmic contraction. Males may start to secrete seminal fluid and the testicles rise closer to the body. In anatomy, the urinary bladder is a hollow, muscular, and distensible (or elastic) organ that sits on the pelvic floor in mammals. ... This article or section is in need of attention from an expert on the subject. ... Horse semen being collected for breeding purposes. ... The penis (plural penises, penes) is an external male sexual organ. ... Human male anatomy The testicles, known medically as testes (singular testis), are the male generative glands in animals. ...

At this stage females show a number of effects. The areola and labia further increase in size, the clitoris withdraws slightly and the Bartholin glands produce further lubrication. The tissues of the outer third of the vagina swell considerably, and the pubococcygeus muscle tightens, reducing the diameter of the opening of the vagina and creating what Masters and Johnson refer to as the orgasmic platform. For the women who never achieve orgasm, this is the peak of sexual excitement. Both men and women may also begin to vocalize involuntarily at this stage. Cross section of the breast of a human female. ... Parts of a vulva The external genital organs of the female are collectively known as the vulva (also sometimes called the pudenda). ... The clitoris (Greek ) is a sexual organ that is present in biologically female mammals. ... The Bartholins glands (also called Bartholin glands or greater vestibular glands) are two glands located slightly below and to the left and right of the opening of the vagina in women. ... Vaginal lubrication is the naturally produced lubricating fluid that reduces friction during sexual intercourse. ... The pubococcygeus muscle or PC muscle is an important muscle in the human body. ... In the plateau phase of the human sexual response cycle in women, the tissues of the outer third of the vagina swell considerably, and the pubococcygeal muscle tightens, reducing the diameter of the opening of the vagina and creating what Masters and Johnson call the orgasmic platform. ...

Prolonged time in the plateau phase without progression to the orgasmic phase may result in frustration if continued for too long (see Orgasm control). Orgasm control (a. ...

Orgasmic phase

Main article: Orgasm

Orgasm is the conclusion of the plateau phase of the sexual response cycle, and is experienced by both males and females. It is accompanied by quick cycles of muscle contraction in the lower pelvic muscles, which surround both the anus and the primary sexual organs. Women also experience uterine and vaginal contractions. Orgasms are often associated with other involuntary actions, including vocalizations and muscular spasms in other areas of the body, and a generally euphoric sensation. // An orgasm (sexual climax) is the conclusion of the plateau phase of the sexual response cycle, and is experienced by both males and females. ... This article is about female reproductive anatomy. ... The vagina, (from Latin, literally 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. ...

In men, orgasm is usually associated with ejaculation. 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. Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm. ...

Orgasms in females may also play a significant role in fertilization. The muscular spasms are theorized to aid in the locomotion of spermatozoa up the vaginal walls into the uterus. Categories: Biology stubs ... Schematic diagram of a sperm cell, showing the (1) acrosome, (2) cell membrane, (3) nucleus, (4) mitochondria, and (5) flagellum (tail) A sperm cell, or spermatozoon ( spermatozoa) (in Greek: sperm = semen and zoon = alive), is the haploid cell that is the male gamete. ...

Resolution phase

The resolution phase occurs after orgasm and allows the muscles to relax, blood pressure to drop and the body to slow down from its excited state.

Men and women may not experience this refractory period and further stimulation may cause a return to the plateau stage. This allows the possibility of multiple orgasms in both sexes. However, some may find continued stimulation to be painful after the orgasmic phase. An orgasm, also known as a sexual climax, is a pleasurable psychological or emotional response to prolonged sexual stimulation. ...

In addition, refractory periods range from human to human, with some being immediate (no refractory) and some being as long as 12 to 24 hours.

Duration of sexual intercourse

Intercourse often ends when the man has ejaculated. Thus the woman might not have time to have an orgasm. In addition, many men suffer from premature ejaculation.^[1] // An orgasm (sexual climax) is the conclusion of the plateau phase of the sexual response cycle, and is experienced by both males and females. ... This article or section is in need of attention from an expert on the subject. ...

According to a Kinsey study, just under half of men reported a time to ejaculation from intromission of five minutes or less. About a fifth claimed that coitus lasted 10 minutes or longer. Others may have taken over one hour. Taking too long, however, can turn pleasure into pain. Kinsey can refer to: Alfred Kinsey, entomologist and father of the field of sexology Kinsey, the 2004 film about Alfred Kinsey This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... Sexual penetration (as opposed to outercourse) typically involves the insertion of the penis into a bodily orifice. ...

How long should sex last? A survey conducted in July 2004^[2] showed the following:

• Women:
  • Ten minutes: 6%
  • Thirty minutes: 17%
  • Until I orgasm: 32%
  • As long as possible: 44%

• Men:
  • Five minutes: 1%
  • Ten minutes: 5%
  • Twenty to thirty minutes: 26%
  • Forever: 28%
  • Until she comes: 34%
  • Until she goes: 4%

In spite of the common belief that women need more time to get aroused, recent scientific research showed that there is no considerable difference for time men and women require to get fully aroused. Scientists from McGill University Health Centre in Montreal, Canada used the method of thermal imaging to record baseline temperature change in genital area to define the time necessary for sexual arousal. Researchers studied the time required for an individual to reach the peak of sexual arousal while watching sexually explicit movies or pictures and came to the conclusion that on average women and men took almost the same time for sexual arousal - around 10 minutes.^[3] The time needed for foreplay is very individualistic and varies from one time to the next depending on many circumstances.^[3] The McGill University Health Centre (MUHC) is a network of five teaching hospitals in Montreal, Quebec, Canada, all of which are affiliated with McGill University. ... Nickname: Motto: Concordia Salus (well-being through harmony) Coordinates: , Country Province Founded 1642 Established 1832 Government  - Mayor Gérald Tremblay Area [1][2][3]  - City 365. ... Example of a thermal column between the ground and a cumulus This article is about the atmospheric phenomenon. ... For other uses, see Temperature (disambiguation). ...

"As a rule, women would like to devote as much time to foreplay and the sex act as men would like to devote to foreplay, the sex act, and building a garage."^[4]

See also

• Sexual attraction
• Foreplay
• Oral sex
• Sexual intercourse
• Estrous cycle

In a species that reproduces sexually, sexual attraction is an attraction to other members of the same species for sexual or erotic activity. ... This article does not cite any references or sources. ... Oral sex consists of all sexual activities that involve the use of the mouth, which may include use of the tongue, teeth, and throat, to stimulate genitalia. ... It has been suggested that Duration of sexual intercourse be merged into this article or section. ... The estrous cycle (also oestrous cycle; originally derived from Latin oestrus) comprises the recurring physiologic changes that are induced by reproductive hormones in most mammalian placental females. ...

References

1. ^ Premature ejaculation
2. ^ Maxim July 2004
3. ^ ^{a b} Your introduction to foreplay
4. ^ "Dave Barry's Guide to Marriage And/Or Sex" Pg 26 ISBN 978-0878577255

External links

• Human sexual response on Discovery health
• Human Sexual Response Cycles by Dr. Mitchell Tepper on SexualHealth.com