The Female Sexual Response Cycle

NOTE: Much of the explanation of what takes place is identical between males and females at all four points in the cycle. I'll elaborate fully in the explanations of the female response.

Although I don't expend as much effort on the explanations of the male response, it is, for all intents and purposes, similar in scope as what I've described for the female.

Excitement: Female sexual excitement (or arousal) begins with the introduction of some erotic stimulus. Many people believe that females aren't as "visually" stimulated as males are, but this has been demonstrated in several studies to be a myth.

For some people, excitement can occur with the simple presence of some visual stimulus, but for many it requires significant intimacy, including physical touching, caressing, and perhaps even some mental fantasizing on her part. This phase may come and go several times before the next stage (plateau) is achieved.

This stage can last from a few minutes to several hours, and the following physiological changes take place:

  • Within 10 seconds (perhaps longer in some women), vaginal lubrication begins. This process occurs when the blood vessels within the epithelium of the vagina begin to secrete a clear fluid known as a transudate. A transudate is basically plasma fluid from the blood, and in the vagina is mixed with mucus to become the lubricant that prepares the vagina for penetration. This process takes longer if the female is lying down.
  • The vagina begins to elongate and widen, and the vaginal opening (the introitus) begins to relax in preparation for an expected penetration.
  • The uterus ascends, resulting in what is known as a "tenting effect." The tenting effect causes the vagina to elongate, increasing form its normal size of 4 inches to perhaps as long as 7 inches. The uterus also begins to get slightly larger, due to vasoconstriction (the accumulation of blood in the vessels in the uterine walls)
  • The uterine walls may begin to fibrillate (contract). Typically, the female will not be aware of this.
  • The vaginal walls become engorged with blood and get darker (due to the pooling of the blood).
  • The labia minora flatten out and become larger, and the labia majora flatten out and withdraw from the introitus.
  • The clitoris becomes larger in diameter (though not in length, typically). This is also the result of vasoconstriction, not unlike what happens with the male's penis when it becomes erect.
  • The nipples become erect, the areola become darker and may become wider. The breasts may expand by as much as 25% ( esp. in women who've breast-fed infants, and is due to fluid accumulation).
  • A sex "flush" begins to appear in about 2/3 of women. Areas of the skin get redder from the dilation of blood vessels. This usually begins in the neck and lower abdominal regions, but may spread to the rest of the body.
  • Muscle tension (known as myotonia) increases throughout much of the body. This leads to grimaces, muscle spasms, and eventually the spams that are felt as the orgasm,
  • Diagram showing three variations of the female sexual response cycle and Male Sexual Response Cycle

    Line A: Typical sequential (multiple) orgasm model - plateau is followed by orgasm, then back to plateau, followed by additional orgasms. This cycle may result in orgasms for as long as a minute or more.
    Line B: Female will go into plateau but fail to reach orgasm and move into resolution. This is a common pattern among younger females and in cases where stimulation is insufficient to produce orgasm.
    Line C: The most common model where a female will have a single, intense orgasm that lasts 5 - 10 seconds, and then moves immediately into resolution.

    Plateau: The plateau phase represents the height of sexual stimulation, generally signifies an impending orgasm, and is typically reached after a period of continued physical and mental sexual stimulation. This phase may be reached multiple times without progressing to the next one. Typically this phase lasts from a few seconds to three or four minutes, though many women find that prolonging this period can result in much strong orgasms. In the plateau phase, the following occurs (assuming the continued presence of erotic stimuli).

      The outer portion of the vaginal wall becomes greatly engorged with blood, thereby reducing the size of the opening. This creates what is referred to as the orgasmic platform. This will be the source of the muscular contractions in the vagina during the orgasm.
      The labia minora become larger and redder in color.
      The clitoris withdraws slightly under the clitoral hood.
      Uterine fibrillations continue and may increase; the uterus elevates further.
      The nipples become firmer and the breasts reach their maximum size.
      The sex flush, if present, becomes more pronounced.
      The heart rate, breathing rates and blood pressure all increase, dramatically in some cases.
      Muscular tension continues to increase.

    Orgasm: The orgasmic phase, if it occurs (it may not in as many as 20% of all women), typically begins within 10-20 minutes after penetration (though often quicker if penetration is preceded by other physical stimulation). An orgasm represents the "release" of all of the pent-up tension in the pubic area and the musculature of the lower body. Some women (approx. 14%) are capable of moving back and forth from the orgasm stage and plateau stage multiple times without going through a resolution period (i.e., having sequential, multiple orgasms). Orgasms typically involve a loss of awareness and sense of time, but may also be relatively subtle. The orgasm process involves:

    Strong contractions occur in the muscles of the vagina. Typically, the first contraction lasts 2 to 5 seconds and is followed by a series of rhythmic contractions that last less than one second each. These will generally be of less intensity as the first contraction, and there may be as many as three to 15 of these.The pituitary gland releases oxytocin. This results in the next three events:

  • The uterus contracts, beginning at the top (fundus) and moving down toward the cervix.
  • Rhythmic contractions also occur in the uterus
  • The nipples intensely harden and become erect
  • The anus rhythmically contracts along the same time frames (the muscles are interconnected with the ones providing the orgasm in the vagina).
  • The inner two thirds of the vagina expand to facilitate movement of the penis within it.
  • The sex flush, if present, peaks in intensity and coverage.
  • The heart rate, breathing rate and blood pressure peak.
  • The body releases a series of hormones known as endorphins, which cause a sense of well-being and "feeling good."
  • There may be involuntary muscular contractions in the hands, feet, and limbs, resulting in clawing motions, followed by a release in the tension.
  • These are known as carpopdeal spasms.

    Resolution: After orgasm, if the erotic stimuli decrease or disappear, the female will enter the resolution phase, and her physiological condition will return to a "normal" state. Women experience no refractory period—they can either enter the resolution stage or return to the plateau stage immediately following orgasm and the process may repeat ad infinitum. Once the resolution phase begins, the following occurs:

  • In less than 10 seconds after orgasm subsides, vaginal contractions subside and the clitoris retracts.
  • The heart rate, breathing rate and blood pressure begin to return to normal rates.
  • The labia minora return to their normal color within a couple of minutes.
  • The cervical os (the opening from the vagina into the uterus) relaxes to allow sperm (if present) to enter the uterus. This closes about 30 minutes after orgasm.
  • Muscle tension decreases over a period of about five minutes. The breasts return to a normal size after about five to ten minutes as well.
  • After about ten minutes the uterus returns to its normal size and position.
  • Within an hour or so, the labia majora relax and return to their position covering the introitus.
  • For some women, the desire to sleep becomes strong. In others, adrenaline acts to prevent sleep and they become more active.
  • Muscle tension decrease