The sexual response cycle
The term ‘sexual response cycle’ was first used by William Masters and Virginia Johnson (1966) to describe the bodily responses or the changes in the body of men and women when they become sexually aroused. There are four identified stages that occur in the sexual response cycle – the excitement stage, plateau, orgasm, and the resolution stage. Each of these stages will be explored in some detail later in this essay. The similarities and differences of experiences of men and women in the four stages of the sexual response cycle will also be explored.
Two very important characteristics of the sexual response cycle in both men and women are vasocongestion and myotonia.
Vasocongestion denotes the swelling of the genital tissues due to increased vascular blood flow into the genital tissues. The increased blood flow into the genital tissues is the cause of erection of the penis in men. In women, the increased blood flow into the genital tissues results in the hardening (or swelling) of the clitoris, lubrication of the vagina, and the swelling of the tissue around the vaginal opening. The inner part of the vagina also enlarges. (Rathus, 2004)
Myotonia on the other hand – as used in the sexual response cycle – refers to the muscle tension which causes facial grimaces, contortions in the hands and feet, and the eventual spasms of orgasm. (Rathus, 2004)
Erection in men, hardening of the clitoris, swelling of the vaginal surroundings, and vaginal lubrication in women, and orgasm in both men and women are all reflexes that signify a response to appropriate or adequate sexual stimulation.
In both men and women, vasocongestion occurs in the excitement phase of the sexual response cycle. An additional feature in men during this phase is the thickening (or ‘shrinking’) of the scrotal skin and an increase in size of the testes. This, and the erection of the penis occur as a reflex response to sexual arousal and this takes a few seconds to manifest. In women, the features of vasocongestion during excitement may manifest between 10 to 30 seconds after sexual arousal. (Rathus, 2004)
Also, during the excitement phase in women, the breasts enlarge and the blood vessels become more visible around the breasts. In both men and women, the nipples may become erect and there is an increase in the heart rate and blood pressure. This may be evidenced by heavy and fast breathing. (Nevid and Rathus, 2005)
The plateau phase of the sexual response cycle is typified by a stability in the characteristics described under the excitement phase. For men, the penis remains erect in a ready state for penetration. Thus the head of the penis becomes bigger in circumference. Also, the testes is in an elevated position that makes it ready for ejaculation. In women, the lubrication of the vagina and a further enlargement of the vaginal tissues prepares the vagina for the penetration of the penis. The clitoris also shortens and receded into the clitoral hood. Breathing in both men and women become faster and the heart rate may increase to between 100 and 160 beats per minute. There is a further increase in blood pressure in both men and women. (Nevid and Rathus, 2005)
In the orgasm phase of the sexual response cycle, men experience contractions of muscle that drives the semen from the testes and results in a pleasurable sensation. The intensity of the sensation and pleasure depends on how strong the contractions are and the amount of seminal fluid emitted. Generally, the first three to four contractions that results in orgasm are the most fervent. These contractions occur in intervals of about 0.8 seconds. The fervency of additional contractions are not that rapid and are thus not as intense as the first three to four contractions.
In women, orgasm occurs when there is a series of contractions of the pelvic muscles around the vaginal area. The frequency of the contractions varies and is between 3 to 15. Like contractions in men during orgasm, the first contractions are in females are the most intense and they occur at intervals of 0.8 seconds. There is a decline of intensity and speed of contractions that follow the initial contractions.
In both men and women, the phase of orgasm witnesses a climax in the heart beat and blood pressure with the heat beat reaching up to 180 per minute.
The final phase in the sexual response cycle is the resolution phase where both men and women return to their normal pre-arousal state. In men, after ejaculating, the penis becomes flaccid as the blood contained in the engorged genital tissues is released. Similarly in women, blood is released from the engorged genital areas and other areas like the breasts. The heart rate and blood pressure in both men and women return to normal and there may be a relaxed and satisfied feeling. (Rathus, 2004)
Whereas women can be sexually aroused again immediately after orgasm and can thus experience multiple orgasms, men enter into a refractory period where they cannot be sexually aroused for some time. The time lapse in the refractory period varies and age plays an important role in the variation of recovery from the refractory period. In adolescents this may take a few minutes while in men over 50 years this may take several minutes, hours or even up to a day. (Nevid and Rathus, 2005)
The sexual response cycle described above is what normally pertains in both men and women during sexual activity. There are however exceptions to the norms described above and one exception that will be discussed briefly is sexual dysfunction. Sexual dysfunction can occur in both men and women when there is a persistent failure to become sexually aroused or to reach orgasm. In men sexual dysfunction may be evidenced by a failure to achieve or sustain an erection and/or an inability to derive excitement or pleasure from sexual activity. Other occurrences like premature ejaculation or inability to ejaculate despite being adequately stimulated are also examples of sexual dysfunction in men. In women, sexual dysfunction may occur when the vagina is not lubricated enough to enable a progression in the sexual response cycle. Experience of pain during sex and inability to reach orgasm are also some examples of female sexual dysfunction. (Rathus, 2004)
The cause of sexual dysfunction can be varied – organic, emotional, psychological, medication, life style choices like smoking, drinking, etc. treatments are also very varied depending on the kind of dysfunction. Whereas counselling therapy may be useful for a dysfunction stemming from emotional or psychological causes, medicines like sildenafil can help men who cannot achieve or maintain an erection to do so. Life style changes like exercising and smoke cessation can also help.
Masters, W. H., and Johnson, V.E. (1966). Human Sexual Response
Toronto: Bantam Books
Nevid, J. S. and Rathus, S. A. (2005) Psychology and the Callenges of Life.
NJ: John Wiley and Sons Inc.
Rathus, S. A. (2004) Psychology: Concepts and Connections