The Four Phases of the Human Sexual Response Cycle

Ousmane Ag Health 100

10-4-2004 Prof. Trowers

THE FOUR PHASES OF THE HUMAN SEXUAL RESPONSE CYCLE.

One aspect of human sexuality that sometimes goes unknown or misunderstood is the sexual response cycle of men and women. You may be wondering what exactly is a sexual response cycle. In very general terms, the sexual response cycle is the sequence of events that happens physiologically when we become sexually aroused and participate in sexually stimulating activities, including intercourse, heavy petting, masturbation, etc.

Two researchers in the area of human sexuality are William Masters and Virginia Johnson. Masters and Johnson conducted studies beginning in the 1950's. They wanted to learn more about what physically happened to the body during sexual arousal and activity. Through their research, they determined that there are at least four different stages that someone goes through from the beginning of arousal to the time after orgasm. These phases, in order, are excitement, plateau, orgasmic, and resolution. Both men and women go through these stages, however the timing is usually different. I will discuss this more later, but please keep in mind as you read my essay that there is much variety from person to person in the amount of time spent in each phase and how each person responds in each phase.

The first phase in the sexual response cycle is called excitement. In women, lubrication occurs in the vaginal lining. This usually begins between 10 and 30 seconds after erotic stimulation. This lubrication makes the insertion of the penis easier and more enjoyable. This lubrication is in part due to an increase in blood flow in the vaginal tissues. A woman's nipples may become erect. In men, the penis becomes erect to some degree, responding in a matter of seconds to erotic stimulation. A man's nipples may also become erect. In both men and women, heart rate, blood pressure, and breathing occur at an accelerated rate. This stage may last anywhere from a few minutes or less to many hours.

The second phase in the sexual response cycle is called plateau. The changes that began to take place in the first phase continue to progress during this phase until orgasm. This phase for women consists of an enlargement of the outer third of the vagina because of swelling from increased blood flow, and the color of the vagina's walls turn a dark purple. The vaginal walls become longer and less wrinkled. The clitoris also retracts back under the clitoral hood, avoiding direct stimulation by the penis. In men, the testes are withdrawn up into the scrotum. For both men and women, breathing, heart rate, and blood pressure continue to increase. Muscle spasms in the feet, face, and hands may begin during this time as well. Tension in the muscles is also increasing until the next stage....

The orgasmic phase is the third phase in the sexual response cycle. Just as the name implies, this is the climax of the cycle. It is the shortest of the three cycles, usually lasting