science

Human sexual response cycle

Human sexual response cycle is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Human sexual response cycle rather than just read about it. In short: The human sexual response cycle is a four-stage model of physiological responses to sexual stimulation, which, in order of their occurrence, are the excitement, plateau, orgasmic, and resolution phases. This physiological response model was first formulated by William H.

Key takeaways

Human sexual response cycle belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Human sexual response cycle to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Human sexual response cycle from memory before moving on to harder problems.

Reference excerpt

The human sexual response cycle is a four-stage model of physiological responses to sexual stimulation, which, in order of their occurrence, are the excitement, plateau, orgasmic, and resolution phases. This physiological response model was first formulated by William H. Masters and Virginia E. Johnson, in their 1966 book Human Sexual Response. Since that time, other models regarding human sexual response have been formulated by several scholars who have criticized certain inaccuracies in the human sexual response cycle model.

Excitement phase The excitement phase (also known as the arousal phase or initial excitement phase) is the first stage of the human sexual response cycle, which occurs as a result of physical or mental erotic stimuli, such as kissing, making out, fantasizing or viewing erotic images, that leads to sexual arousal. During this stage, the body prepares for sexual intercourse, initially leading to the plateau phase. There is wide socio-cultural variation regarding preferences for the length of foreplay and the stimulation methods used. Physical and emotional interaction and stimulation of the erogenous zones during foreplay usually establishes at least some initial arousal.

Excitement in both sexes

Among both sexes, the excitement phase results in an increase in heart rate, breathing rate, and a rise in blood pressure. A survey in 2006 found that sexual arousal in about 82% of young females and 52% of young males arises or is enhanced by direct stimulation of nipples, with only 7–8% reporting that it decreased their arousal. Vasocongestion of the skin, commonly referred to as the sex flush, will occur in approximately 50-75% of females and 25% of males. The sex flush tends to occur more often under warmer conditions and may not appear at all under cooler temperatures. 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 the order in which it appeared. 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).

Excitement in males In males, the beginning of the excitement phase is observed when the penis becomes partially or fully 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.

Excitement in females In females, the excitement phase can last from several minutes to several hours. The onset of vasocongestion results in swelling of the woman's clitoris, labia minora and vagina. The muscle that surrounds the vaginal opening grows tighter and the uterus elevates and grows in size. The vaginal walls begin to produce a lubricating organic liquid. Meanwhile, the breasts increase slightly in size and nipples become hardened and erect.

Plateau phase

The plateau phase is the period of sexual excitement prior to orgasm. The phase is characterised by an increased circulation and heart rate in both sexes, increased sexual pleasure with increased stimulation and further increased muscle tension. Also, respiration continues at an elevated level. Prolonged time in the plateau phase without progression to the orgasmic phase may result in sexual frustration.

Plateau in males During this phase, the male urethral sphincter contracts (preventing urine from mixing with semen, and retrograde ejaculation) and muscles at the base of the penis begin a steady rhythmic contraction. Males may start to secrete seminal fluid or pre-ejaculatory fluid and the testicles rise closer to the body.

Plateau in females The plateau stage in females is basically a continuation of the same changes evident in the excitement stage. The clitoris becomes extremely sensitive and withdraws slightly, and the Bartholin glands produce further lubrication. The tissues of the outer third of the vagina swell, and the pubococcygeus muscle tightens, reducing the diameter of the opening of the vagina. Masters and Johnson refer to the changes that take place during the plateau stage as the orgasmic platform.

Orgasm phase

Orgasm is experienced by both males and females, ending the plateau phase of the sexual response cycle. Orgasm is accompanied by quick cycles of muscle contraction in the lower pelvic muscles, which surround both the anus and the primary sexual organs. Orgasms are often associated with other involuntary actions, including vocalizations and muscular spasms in other areas of the body and a generally euphoric sensation. Heart rate is increased even further. Tantric sex practices may seek to diminish the goal of achieving orgasm, which is frequently a common goal of sexual intercourse.

Orgasm in males In males, orgasm is usually associated with ejaculation. Each ejaculation is accompanied with continuous pulses of sexual pleasure, especially in the penis and surrounding area. Other sensations may be felt strongly among the lower spine or lower back. 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 sensation of pleasure.

Orgasm in females Women also experience uterine and vaginal contractions. Orgasms in females can vary widely from individual to individual. They are commonly associated with an increase in vaginal lubrication, a tightening of the vaginal walls and overall pleasure. For some women, there is also a possibility of female ejaculation.

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Worked examples

Example 1 — a first encounter with Human sexual response cycle

Start with the simplest possible case. Write down what Human sexual response cycle claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Human sexual response cycle before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Human sexual response cycle ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Human sexual response cycle

In research: Human sexual response cycle appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Human sexual response cycle in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Human sexual response cycle is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fertility, Sexual arousal, so understanding it makes those chapters shorter.
In everyday life: Look for Human sexual response cycle outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Human sexual response cycle in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Human sexual response cycle means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Human sexual response cycle out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Human sexual response cycle in simple terms?

Why does Human sexual response cycle matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Human sexual response cycle?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Human sexual response cycle.