Orgasm is the sudden discharge of accumulated
sexual tension resulting in rhythmic muscular contractions
in the pelvic region that produce intensely pleasurable
sensations followed by rapid relaxation. It typically lasts
for several seconds.
Orgasm is also in part a psychological experience
of pleasure and abandon, when the mind is focused solely
on the personal experience. It is sometimes called climaxing
or coming.
In Masters and Johnson's original research
of the human sexual response cycle, orgasm is the third
of four stages, occurring after the plateau phase and before
the resolution phase. Another widely accepted model of the
sexual response cycle, developed by Helen Singer Kaplan,
M.D., PhD., involves just three stages: desire, excitement
and orgasm.
Orgasms vary from person to person and for
each individual at different times. Sometimes orgasm is
an explosive, amazing rush of sensations, while others are
milder, subtler, and less intense. The differences in intensity
of orgasms can be attributed to physical factors, such as
fatigue and length of time since last orgasm, as well as
to a wide range of psychosocial factors, including mood,
relation to partner, activity, expectations, and feelings
about the experience.
A Total Body Response
There are several physiological components of orgasm. First,
orgasm is a total body response, not just a pelvic event.
Brain wave patterns have shown distinct changes during orgasm,
and muscles in many different areas of the body contract
during this phase of sexual response. Some people experience
the involuntary contraction of facial muscles resulting
in what looks like a grimace or an expression of discomfort
or displeasure, but it is actually an indication of high
sexual arousal.
The most characteristic physical feature
of orgasm is the sensation produced by the simultaneous
rhythmic contractions of the pubococcygeus muscle (pc muscle).
Along with contractions of the anal sphincter, rectum and
perineum, the uterus and outer third of the vagina (the
orgasmic platform) for women, and the ejaculatory ducts
and muscles around the penis for men, this constitutes the
reflex of orgasm.
The first few contractions are intense and
close together, occurring at about 0.8-second intervals.
As orgasm continues, the contractions diminish in intensity
and duration and occur at less frequent intervals.
Differences Between Men and Women
Despite the anatomical differences between male and female
genitals, orgasms in men and women are physiologically and
psychologically, or subjectively, very similar.
In fact, studies have been done in which
"experts" could not reliably determine gender
when reading descriptions of orgasms with all anatomical
references removed.
Women have described the sensations of orgasm
as beginning with a sense of suspension, quickly followed
by an intensely pleasurable feeling that usually begins
at the clitoris and spreads throughout the pelvis. The genitals
are often described as becoming warm, electric or tingly,
and these physical sensations usually spread through some
portion of the body. Most women also feel muscle contractions
in their vagina or lower pelvis, often described as "pelvic
throbbing".
The subjective feeling of orgasm in men
has been described quite consistently as beginning with
the sensation of deep warmth or pressure that corresponds
to ejaculatory inevitability, the point when ejaculation
cannot be stopped. It is then felt as sharp, intensely pleasurable
contractions involving the pc muscles, anal sphincter, rectum,
perineum and genitals. Some men describe this part as a
sensation of pumping. Finally, a warm rush of fluid or a
shooting sensation describes the actual process of semen
travelling through the urethra during ejaculation.
It is important to note that orgasm and
ejaculation are not one in the same event. Although they
typically occur together, a man may have an orgasm without
ejaculating.
A major difference between the female and
the male orgasmic phase is that far more women than men
have the physical capability to have one or more additional
orgasms within a short time without dropping below the plateau
of sexual arousal.
Being multi-orgasmic depends on both continued
stimulation and sexual interest. Because neither of these
is present every time for most women, multiple orgasms do
not occur with every sexual encounter.
On the other hand, upon ejaculation, men
enter a recovery phase called the refractory period. During
this time, further orgasm or ejaculation is physiologically
impossible. However, some men can learn to have an orgasm
without ejaculating, thereby making it possible to experience
multiple orgasms.