Stages of Sexual Response
The first stage of sexual response is desire. Sexual desire involves a strong want for sexual stimulation and/or sexual intimacy. This phase may be referred to as physical attraction, longing, or yearning.
Sexual desire is influenced by personal preferences, as well as social and cultural factors. It involves a mental response to a number of different stimuli. Sight, sound, touch, smell, taste, memory, and fantasy can stimulate or contribute to sexual desire.
Desire is a mental response that may or may not be expressed, either verbally or through actions or behavior (e.g., body language, flirting). Sexual desire may or may not progress to the next stage of sexual responsesexual arousal.
Sexual arousal, or excitement, is the second phase of the sexual response cycle. Sexual excitement is a physical reaction to sexual desire.
The level of sexual stimulation required to cause sexual arousal varies considerably from person to person and with each sexual experience. Some people (especially adolescents and young adults) experience arousal with little physical or mental stimulation, and others require physical stimulation and/or a certain level of emotional intimacy to achieve sexual arousal. Typically, men are sexually aroused more easily than women.
Sexual excitement may or may not be expressed, either verbally or through actions or behavior. Physical signs of arousal include increased heart rate, breathing, and blood pressure; muscle tension; and reddening of the skin of the face, neck, back, and chest (called flushing). Blood flow to the pelvis and genitals increases and the nipples harden.
In men, the penis becomes erect (called an erection), the testicles (testes) are pulled closer to the body, and the scrotum thickens. In women, the vagina swells (i.e., lengthens and widens) and becomes lubricated, the clitoris enlarges, the labia minora swell and separate, the uterus rises slightly within the pelvis, and the breasts become larger.
If sexual stimulation continues, the next stage in the sexual response cycle may occur. This phase, which is called the plateau stage, may or may not be expressed, either verbally or through actions or behavior.
During the plateau phase of sexual response, a high level of sexual excitement may occur, be lost, and then recur several times. Physical signs of this stage include a further increase in heart rate, breathing, blood pressure, muscle tension, and flushing. The plateau stage also may lead to the sensation that orgasm is about to occur.
In men, the ridge of the glans penis (the head of the organ) becomes more prominent, pre-ejaculatory fluid is secreted, and the testicles are pulled even closer to the body. In women, the clitoris becomes more sensitive and withdraws under the clitoral hood, vaginal lubrication increases, and the vagina and labia continue to swell and tighten.
At the peak of the plateau stage, orgasm occurs. During orgasm, sexual tension is released. The intensity of orgasm varies from person to person and with each sexual experience. It may be very subtle or may involve the entire body and result in a brief loss of awareness. Orgasm may or may not be expressed, either verbally or through actions or behavior.
Just prior to orgasm, heart rate, breathing, blood pressure, and muscle tension reach their highest peak. Physical signs of orgasm include flushing throughout the body and muscle spasms. In men, the urethra (tube that carries urine and semen out of the body through the penis) and muscles in the pelvic floor and anus contract quickly several times, resulting in ejaculation. In women, muscles in the pelvic floor, the vagina, the uterus, and the anus contract quickly several times.
Women are physically capable of returning to the plateau phase of the sexual response cycle immediately following orgasm, but men are not able to achieve an erection until they complete a refractory period and enter the resolution phase of sexual response. The length of the refractory period varies from man to man and with each sexual encounter. This period of time ranges from minutes to hours and often increases with age.
Resolution is the final stage of the sexual response cycle. During this phase, the body returns to normal. Heart rate, breathing, and blood pressure slow, muscles relax, and blood flow to the pelvis and reproductive organs decreases. Many people experience sweating and drowsiness during the resolution phase.