According to
Masters and Johnson the
sexual response cycle starts with the
excitement phase. During this phase Masters and Johnson discovered that heart and
blood pressure change, muscle tension increases,
nipples and
penis become
erect.
Next is the
plateau phase. This is where the intensity changes. There is more intensity than the excitement phase. During this phase there becomes the male inevitability to have an
orgasm.
The third phase is the
orgasm phase. This is when there is male
emission, and
expulsion. The heart rate increases for both partners. Muscles contract. Females enter an orgasmic platform where they may be able to have
multiple orgasms.
The last phase is the
resolution phase. During this phase the male turns to an unaroused state and enters his
refractory period. The refractory period generally lengthens with age. Females also return to an unaroused state. The
cervix lowers to maximize
fertilization and multiple orgasms are possible.
This is based of the research and study of over 10,000
sexual episodes and 700
men and
women.