The feeling of an orgasm is understood by many. There are sparks and explosions throughout the body, and a warm sensation follows.
But, probably less-known is the science behind what exactly is going down in the body.
As it prepares for climax, vital signs are at their peak, and muscles in the pelvis, face, and toes are tense. Then follows the sudden, forceful release of that sexual tension in the form of muscular contractions.
The orgasm doesn’t exist in a vacuum—it’s just one part of the sexual response system.
To understand the science of the orgasm, we must break down the sexual response cycle into the following: excitement, plateau, orgasm, and resolution.
In the excitement stage, muscle tension and heart rate increase, skin may become flushed, the nipples erect, women’s breasts become fuller, and blood flows to the clitoris or penis, causing swelling.
The plateau stage, despite its lackluster name, is an intensified version of the excitation stage.
Blood flow and subsequent swelling occurs, the vaginal wall turns dark purple, the clitoris becomes very sensitive (with some people, it becomes even painful to touch and retracts under the hood to avoid excess stimulation).
Following the plateau stage is the orgasm itself.
In comparison to the other stages, it doesn’t last very long. And you know what happens.
Finally, the orgasm enters the resolution stage. The body returns to its normal levels, and body parts that were swollen or changed color return to normal as well.
There are some differences in the way people with female reproductive systems and male reproductive systems, from here on referred to females and males, orgasm. (Transgendered individuals and intersex people may have unique reactions that differ from the male/female dichotomy.)
In females, the vaginal walls, uterus, pelvic muscles, and anus contract. Females’ orgasms average 20 seconds, but can last up to a minute. Females also don’t require a refractory period, giving them the ability to orgasm multiple times.
In males, orgasms last three to 10 seconds. The contractions come from the anal sphincter, penis muscles, and prostate gland. The force of these contractions release semen.
However, men can also experience dry orgasms in which no fluid is released. Males require a refractory period before they can orgasm again.
Females can also ejaculate (colloquially referred to as “squirting”). Activation of the g-spot, a sensitive area two inches into the vagina on the front wall, can cause females to ejaculate fluids from the bladder and the female prostate. In both men and women, muscles in other part of the body, including the legs and feet, are affected.
The brain experiences many changes during an orgasm, too.
The lateral orbitofrontal cortex, a part right behind the left eye that controls behavior and acts as the “voice of reason,” is shut down during an orgasm. The periaqueductal gray, which interprets fight or flight, is activated in women only. Women also experience a decrease in amygdala and hippocampus activity, which decreases fear and anxiety during sex.
The brain releases dopamine and oxytocin, leading to the euphoric feelings—ultimately, what makes the experience enjoyable.