The Plateau Phase

Human sexual response is divided into four phases – excitement, plateau, orgasmic, and resolution – for reasons of convenience.

There is no sharply defined moment in time when one phase ends and the next begins – and this is particularly true of the relatively vague boundary which separates the excitement from the plateau phase.

In the male full erection of the penis is ordinarily completed during the excitement phase. The only additional changes in the penis during the plateau phase are a slight increase in diameter of the “coronal ridge” at the base of the glans of the penis; and in some men on some occasions, a deepening of the reddish-purple colour of the glans.

The testes increase in diameter about 50 per cent over their unstimulated size; and they are pulled up even higher into the scrotum by a further shortening of the spermatic cord Indeed, the full elevation of the testes is a sign that a man has reached the “point of no return”, and that his orgasm is imminent. If the man’s nipples did not erect earlier, they may erect now.

In both men and women, the rate of breathing increases during the plateau phase, and there is a further increase in pulse rate and blood pressure.

The sex flush may now appear, or may become more marked and widespread if it appeared earlier. The tension of both voluntary and involuntary muscles is heightened; and there may be almost spastic contractions of some sets of muscles in the face, ribs, and abdomen.

The sphincter muscle, which holds the rectum closed, may tighten up; indeed, some men and women tighten up both this muscle and the muscles of the buttocks as a deliberate means of heightening tension.

In the female breasts, there is a further swelling of the areolas surrounding the nipples. This is often so marked as partially to mask the erection of the nipples; they may look shorter as a result. But in fact, there may be a further swelling of the nipples under the areolar mask.

If coitus is prolonged, a few drops of moisture may emerge from the Bartholin’s glands imbedded in the woman’s outer lips, as noted above. A few drops of moisture may also emerge from the male urethra.

This fluid probably comes from Cowper’s glands – the male equivalent of the female Bartholin’s glands. The fluid is not semen; but it is important to know that large numbers of active sperm cells are sometimes found in it.

Thus there is at least a possibility that a woman may become pregnant following the secretion of these preliminary droplets. That’s true even with the withdrawal of the penis before semen is actively ejaculated. 

The most dramatic change in women during the plateau phase is the appearance of the “the orgasmic platform.” This is the engorgement and swelling of the tissues surrounding the outer third of the vagina.

As a result of this swelling, the diameter of the outer third of her vagina is reduced by as much as 50 per cent. It thus actually grips the penis, and the erotic stimulus experienced by the man is notably increased.

The appearance of the orgasmic platform, however, does not necessarily mean that a woman is ready for orgasm during intercourse.

A man has to know how to arouse a woman, and indeed if he wants to help a woman climax, he must be sensitive to her level of arousal.

Accompanying the appearance of the orgasmic platform is a further elevation of the uterus, and a further ballooning of the inner two-thirds of the vagina.

The uterus also becomes enlarged during this phase; it may even double in size in women who have had babies.

Among women who have not had babies, the size increase is less impressive, but it is noticeable in many cases.

Another dramatic change during the plateau phase is the elevation of the clitoris.

In the process of elevation, the clitoris rises from its normal position overhanging the pubic bone, and seems to become retracted.

It is drawn further away from the vaginal entrance.

The clitoral shaft is shortened by as much as 50 per cent following elevation, and it may seem to be lost altogether, or harder to find.

It continues to respond to stimulation, however, either directly applied to the mons veneris, or indirectly through the thrusting of the penis into the vagina.

The outer lips of the vagina of women who have had babies may become even more engorged during the plateau phase than during the excitement phase; and even in women who have never had a child there may be some swelling of the outer lips if erotic stimulation has been prolonged.

The inner lips change colour late in the plateau phase, from bright red to a deep wine colour in women who have had children, and from pink to bright red in women who have not.

This colour change is important, for it is a sure sign that orgasm will occur – usually within a minute or a minute and a half – if effective erotic stimulation is continued.

When a woman fails to reach orgasm despite prolonged stimulation, she also fails to show this tell-tale colour change of the inner lips.

While these many changes, occurring in many parts of both male and female bodies, may seem complex and different from one another, all or almost all of them, as noted earlier, seem to fall into two main classes.

First, the engorgement of blood vessels and other organs, and second, an increase in muscle tension.

Both the male and female achieve readiness for orgasm, it seems likely, when these two processes of increased engorgement with blood and increased muscular tension reach adequate peaks.

The plateau phase is the period during which a woman experiences mounting sexual tension, until she can leap into the orgasmic phase of sexual expression.