4 "Stages" of Sex.....

Four successive (hence, linear) stages: 

(1) Excitement, 

(2) Plateau, 

(3) Orgasm

(4) Resolution.

The first phase, excitement, refers to the initial physiological sexual arousal response as

characterized by increased heart rate, respiration, and blood pressure. In addition, myotonia

(an increase in muscle tension), vasocongestion (engorgement of blood vessels), and nipple

hardening or erection occur. These changes are often accompanied by a flush or reddening

of the skin. In women, a rush of blood causes engorgement of the clitoris, labia majora,

minora, and uterus, with uterine position elevating slightly. Vaginal lubrication also begins with

this stage. In men, the rush of blood causes penile erection and enlargement of the testes,

with the scrotal sac pulling more tightly toward the body.

The plateau phase intensifies the responses from the excitement phase—breathing, blood

flow, and heart rate continue to increase and stabilize. Muscle tension increases and may

extend to hands, feet, face, and other areas of the body. In women as blood flow increases,

the vaginal walls darken and the clitoris becomes increasingly sensitive. The vagina expands

and the uterus becomes fully elevated. The Bartholin glands produce additional lubrication in

and around the vagina. In men, the testicles are drawn further into the scrotal sac and

preseminal fluid from Cowper’s glands may be secreted at the penile opening.

The orgasm phase represents the peak or sexual climax of excitement, though not all men

and women necessarily reach this stage. Orgasm is marked by involuntary, rhythmic muscle

contractions throughout the body as well as a sense of euphoria and a feeling of tension

relief. Women experience contraction of the pelvic muscles surrounding the vagina and

uterus, followed by release of built-up muscle tension. In men, ejaculation/orgasm has two

stages of autonomic response. In the first—known as emission—the vas deferens, seminal

vesicles, and prostate trigger the urethral bulb to expand with seminal fluid, with internal

sphincter contraction closing the bladder neck to prevent urine leakage. In the second—

expulsion—muscles surrounding the base of the penis contract, propelling semen externally.

The last phase is resolution, marked by a return to baseline. Muscles relax, blood pressure

drops, and respiration returns to the pre-arousal state. Blood flow to the genital region

decreases, and erectile tissues return to normal. Masters and Johnson note a typically greater

refractory period in men, such that they are incapable of achieving an immediately successive

orgasm. Women typically have a shorter refractory period, being capable of successive

orgasms in a short period of time.

***William Masters and Virginia Johnson's linear model of human sexual response

#CannaGasm