The Sexual Response Cycle

The sexual response cycle is the phrase coined to describe the bodily responses to sexual arousal. The sexual response cycles are distinguished by myotonia (muscle tension) and vasocongestion (blood engorgement). Mytonia causes muscles spasms, facial contortion, and orgasmic shockwaves. Vasocongestion includes penile enlargement and erection as well as swelling of the vagina, nipples, testes, and even the ear lobes. The sexual response cycle is broken down into the four stages of excitement, plateau, orgasm, and resolution; these stages may be similar or different for males and females. (Nevid & Rathus, 2005)

Excitement Phase

During the excitement phase, both male and female experience genital tissue vasocongestion, mytonia (including nipple erection), and increased blood pressure and heart rate. In males, within the first three to eight seconds following stimulation, vasocongestion causes erection, elevation of testes, and tension and thickening of scrotum skin. In the female, the excitement phase may begin within the first 10 to 30 seconds following sexual stimulation, vasocongestion causes enlargement of vaginal tissue (including the area around the entrance to the vagina and the interior two thirds of the vagina) and the clitoris. The female also experiences a thickening of vaginal walls which darken in appearance, breast enlargement, flushing, and vaginal lubrication. (Nevid & Rathus, 2005)

Plateau Phase

During the plateau phase, vasocongestion and myotonia increase, as does the heart rate and blood pressure for both male and female. In the male, the penile head may increase in size and will become purple in color; the testes may grow one and a half times the pre-arousal size and will be raised in preparation for ejaculation; and pre-ejaculate semen may be released. In the female, the inner two-thirds of the vagina will fully expand while the outer third will thicken to prepare to grasp the penis, the clitoris will shorten and draw in behind the clitoral hood, and the uterus will raise and enlarge in size. (Nevid & Rathus, 2005)

Orgasm Phase

During the orgasmic phase, both male and female reach orgasm which includes powerful pleasure sensation and the release of sexual tension; heart rate, blood pressure, and breathing rate peak; and muscle spasms are experienced throughout the body. Vaginal lubrication, erection, and orgasm are automatic reflexes to sufficient stimulation. (Nevid & Rathus, 2005)

The male may feel the imminence of ejaculation for two or three seconds prior to the ejaculation reflex. The male's orgasmic phase of muscle contraction occurs in two stages: first, the semen accumulates at the penile base while an internal sphincter in the bladder prevents the semen from mixing with urine; second, powerful muscle contractions force the ejaculate from the body. The strength of the male's pleasure sensations appear to correlate with the muscle contraction strength and volume of seminal fluid: the first three or four tend to be more intense and occur approximately one contraction per second. (Nevid & Rathus, 2005)

The female's orgasmic phase consists of pelvic muscle contractions within and surrounding the vagina. The female may experience three to fifteen contractions of the pelvic muscles during orgasm, the first of which occur at a rate of approximately one contraction per second, followed by slower and less powerful contractions. (Nevid & Rathus, 2005)

Resolution Phase

The resolution phase is the body's return to a non-aroused state following orgasm. Both male and female, without further stimulation, will experience a lessening of myotonia and vasocongestion until the body returns to the state prior to arousal and will include a lowering of blood pressure, slower heart beat, slower breathing rate, and the release of blood from areas of engorgement. (Nevid & Rathus, 2005)

The male will experience a refractory period where he is unable, physiologically, to experience another orgasm or ejaculation. The refractory period varies between individuals and may last from a few minutes to a day: age can have a significant impact on the length of the refractory period. During the resolution phase, the male will lose his erection and the testes will shrink to the non-arousal size. (Nevid & Rathus, 2005)

For the female, the resolution phase includes a shrinking of the clitoris and vaginal cavity to the pre-aroused size and breasts and nipples return to the normal size. The female does not experience a refractory period, and she may, with continued stimulation, experience multiple orgasms, if she so desires. (Nevid & Rathus, 2005)

Sexual Dysfunction

Sexual dysfunctions can be experienced by both male and female and are defined as reoccurring problems with arousal, sexual interest, or sexual response. The American Psychiatric Association identifies five major areas of sexual dysfunction, they are: hypoactive sexual desire disorder, female sexual arousal disorder, male erectile disorder, orgasmic disorder, and premature ejaculation. The following is an overview of these dysfunctions, common causes, and treatments. (Nevid & Rathus, 2005)

Hypoactive sexual desire disorder is a loss of interest in sex, reduced sex drive, and a loss of sexual fantasies. Female sexual arousal disorder is characterized by the persistent and reoccurring inability to obtain vaginal lubrication or the inability to retain vaginal lubrication. Male erectile disorder is characterized by the persistent and reoccurring inability to obtain an erection or the inability to maintain an erection during sex. Orgasmic disorder is experienced by both male and female, although more commonly occurs in females, is indicated when he or she is sexually aroused, but has difficulty or is unable to reach orgasm. Premature ejaculation is characterized by rapid ejaculation with minimal sexual stimulation, reducing the male's own and his partner's sexual satisfaction. (Nevid & Rathus, 2005)

Sexual dysfunction can be caused by a variety of different factors. A reduced desire for sex may be caused by diabetes or hormone level imbalance. Fatigue, alcohol, narcotics, and tranquilizers can reduce sexual responsiveness, sexual desire, and inability to achieve orgasm. Health problems, mental health problems, surgical procedures, psychological issues, cultural or religious beliefs, clogged arteries, infections or sexually transmitted diseases, and medications can negatively affect sexual function as well. (Nevid & Rathus, 2005)

Common treatments include hormone replacement therapy, removal of artery blockages, properly management of diseases such as diabetes mellitus, weight loss, medications (Viagra), sex education, and sex therapy. Sex therapy can address performance anxiety, low self esteem, low self efficacy, negative self talk, teaching sexual skills, increase knowledge of biology and sexual functions, and improve communication. (Nevid & Rathus, 2005)

The body's physiological reactions in the sexual response cycle are beyond the realm of fascinating and serve a distinct purpose. Both male and female may experience some form of sexual dysfunction; however, most causes for sexual dysfunction are either physical or psychological in nature and can be diagnosed and treated through a thorough examination by a medical expert: a urologist for males and a gynecologist for females. (Nevid & Rathus, 2005)

References

Nevid, J. S., & Rathus, S. A. (2005). Psychology and the challenges of life: Adjustment in the new millennium (9^th ed.). Hoboken, NJ: John Wiley & Sons.