Psy/210 Sexual Response Cycle

The sexual response cycle is a Masters and Johnson’s model of sexual response which consists of four stages or phases. This model is founded on the theory that male and female sexual stimulation- their sexual response cycles- are very similar with obvious differences due to physical make up. The four phases are the excitement phase (initial phase for male and female), plateau phase, orgasmic phase, and the resolution phase. The phases fall in sequence from the beginning of stimulation up toward the peak of climax and back down to levels of prior stimulation.
The excitement phase- initial phase of the sexual response cycle- takes place due to stimulation. Sexual arousal takes place during this phase and vasocongestion (engorgement of blood vessels with blood, which swells the genitals and breast during sexual arousal) occurs in both male and females. The vasocongestion can cause erection in men and young men can do so in 3-8 seconds. Also, the skin on the scrotum tightens and draws up. The male testes will swell and become elevated during this phase. In women, vasocongestion occurs causing the vaginal tissue, clitoris, and the area around the opening of the vagina to swell. Lubrication appears inside the vagina and the inner vagina expands along with the vaginal wall thickening and becoming a deeper color. In both genders there is swelling of the genital area as stated and also myotonia occurs (muscle tension) along with an increased heart rate and blood pressure.
In the second phase or plateau phase of the sexual response cycle the level of sexual arousal stays somewhat stable. In men, the tip of the penis may become swollen and turn the color of reddish purple. The testes continue to elevate and get in position to ejaculate. The penile opening may release droplets of semen prior to ejaculation. In the female, the inner two-thirds of the vaginal wall expand fully and the outer third of the vagina thickens. The clitoris retracts behind it hood as the uterus