The Sexual Response Cycle

 The sexual response cycle describes what changes the body undergoes as it becomes aroused. It is an individualized process; everyone experiences the cycle differently, although almost all people go through a similar process. It is important to note that the cycle takes place during any sexual activity where a person becomes aroused—masturbation, intercourse, manual stimulation by a partner, oral sex, fantasy, and more.

Over the years, researchers have explored the sexual response cycles of men and women. There are two popular sexual response cycles: Masters and Johnson’s Four Phase Model and Kaplan’s Three Phase Model.

I will say that while most people go through some cycle of the below phases, I don't think one is right and the other wrong.  I also don't think that you can say everyone goes through these phases and if you don't then you have a dysfunction; which is what both of these models say.  I have issues with the term sexual dysfuntion, but that's a whole different blog post. 

Basically, this is kinda what your body is going through when you get aroused and I think it's important for people to understand both of these models. 

Masters and Johnson’s Four Phase Model
Masters and Johnson are perhaps the famous for their sexual response cycle, s tarting their research in 1958. They were under fire several times for "exaggerating the benefits of their intensive treatment program and with failing to disclose the criteria they used to determine whether the therapy had a lasting effect. (NYTimes." The Masters and Johnson Institute opened in 1978 and was located in St. Louis.  Opened to study human sexuality, focusing on anatomy and physiology of the humans sexual response cycle, the institute closed in 1994. The duo is famous for inserting small cameras into the vagina of prostitutes and filming what happens to the vagina when a woman has an orgasm.    

Excitement
The first of the phases, excitement can last anywhere from less than a minute to several hours. There is also an increase in heart rate and blood pressure. Typically, the sexual organs, including the clitoris, labia, and breasts, become engorged with blood (vasocongestion) and often become a deeper color. Lubrication is usually produced in the vagina during the excitement phase.

Plateau
The plateau phase is generally short in length (a few seconds to a few minutes) and the sexual tension that started in the excitement phase continues to grow. Extending the plateau phase sometimes can lead to more intense orgasms. Everything that occurred during the excitement phase continues to occur, but with more intensity—breathing becomes heavier, the sexual organs become a dark color, heart rate and blood pressure continue to rise, and muscle tension increases.

Orgasm
The orgasm phase is the shortest phase of the sexual response cycle, generally only lasting several seconds. Women do not always enter into the orgasm phase; sometimes they stay in the plateau phase. Most women experience rhythmic muscle contractions during the orgasm phase, which can occur in the genitals, as well as all over the body.

Resolution
The resolution phase is the final stage to the sexual response cycle. During the resolution phase, all sexual organs return to their non-aroused shape, size, and color. This change begins immediately after orgasm as long as there is no additional stimulation. The amount of time it takes for a person’s sexual organs to return to their non-aroused state varies between individuals.

Kaplan’s Three Phase Model
 Helen Singer Kaplan modified the Masters and Johnson sexual response cycle based on her work treating sexual dysfunction problems in men and women. Dr. Kaplan added a prior stage of sexual desire and eliminated the resolution and plateau phases.  (see Kaplan, Dr. Helen Singer). 

Desire
A unique stage to this model is the desire phase; most other sexual response cycles do not include this phase. In the desire phase, it is assumed that people want to engage in sexual activity; that they desire the activity and/or another person. Not all sexual activity is desired, though. For example, a couple trying to conceive a child may have sex even if they do not desire the activity.

Excitement
The first of the phases, excitement can last anywhere from less than a minute to several hours. Myotonia, which is categorized by increased muscle tension and flexing and contractions of the muscles, occurs during the excitement phase. There is also an increase in heart rate and blood pressure. Typically, the sexual organs become engorged with blood (vasocongestion), including the clitoris, labia, and breasts, and often become a deeper color. Lubrication is usually produced in the vagina during the excitement phase.

Orgasm
The orgasm phase is the shortest phase of the sexual response cycle, generally only lasting a few seconds. Most women experience rhythmic muscle contractions during the orgasm phase. It is not unusual for people to pass back and forth between phases or for people to miss a phase. Not everyone follows the sexual response cycle exactly as is shown here. It is also common for  people to experience the cycle differently each time they engage in sexual activity. The sexual response cycle simply serves as a model to help to understand the variety of sexual responses that people may experience.