Although the genitals are a key part of sex, its pleasurable sensations involve many parts of the body. Pleasurable sex heavily depends on the brain, which releases hormones that support sexual pleasure and interpret stimulation as pleasurable. An orgasm is a heightened state of sensory awareness that can trigger a trance-like state in the brain. In this article, we examine the effects that sex has on the body and the brain, as well as how these effects make sex feel good. We also take a look at why sex might not feel good.
The brain regulates the four distinct phases of the Sexual Response Cycle, each with unique effects on the body. Research on this, has led to their use to explain sexual response:
1. Desire/Excitement/Arousal
During the desire phase, the tissue in the penis, pelvis, vulva (vagina,labia and clitoris) fill with blood. This increases the sensitivity of nerves in these areas of the body. This blood flow also creates a fluid called transudate, which lubricates the vagina. Muscles throughout the body begin contracting. Some people breathe more rapidly or develop flushed skin due to the increased blood flow.
2. Plateau
During the plateau stage, a person’s arousal continues to intensify. The vagina, penis, and clitoris become more sensitive. A person may experience variations in sensitivity and arousal during this period. Arousal and interest may decrease, intensify, then decrease again.
3. Orgasm
With the right stimulation and the right mental state, a person may have an orgasm.
For most females, clitoral stimulation is the fastest, most effective path to orgasm. For some, it is the only path to orgasm. Males may need prolonged stimulation of the shaft or head of the penis.
Most males ejaculate during orgasm, but it is possible to have an orgasm without ejaculating. Some females also ejaculate during orgasm.
Both males and females experience intense muscle contractions during orgasm. Males experience these contractions in the rectum, penis, and pelvis, while females experience them in the vulva, uterus, and rectum. Some people experience contractions throughout the entire body.
4. Resolution
After orgasm, the muscles relax, and the body slowly returns to its pre-arousal state. This process is different for males and females. Although most males cannot have an orgasm immediately after ejaculating, many females can.
During the resolution stage, most males and many females experience a refractory period. During this time, the person will not respond to sexual stimulation.
The clitoris is, for most females, the point of origination for sexual pleasure. It has thousands of nerve endings, making it highly sensitive. Portions of the clitoris extend deep into the vagina, allowing some women to get indirect clitoral stimulation through the vagina. The clitoris is the only body parts whose only function is sexual pleasure. For men, the head of the penis is similar to the clitoris in that it is often the most sensitive area. The ribbed area at the back of the head is typically most sensitive and is called the frenulum.
For sex to feel pleasurable, the brain has to interpret sexual sensations as pleasurable.
Nerves in the body send specific signals to the brain, and the brain uses those signals to create various sexual sensations. Neurotransmitters are chemical messengers that help the brain communicate with other areas of the body.
Several neurotransmitters have a role in sexual pleasure:
* Dopamine is a hormone linked with motivation and reward. It increases sexual arousal, and the body secretes it during the desire stage.
* The body releases serotonin, which supports feelings of well-being and happiness, during the arousal phase.
* Norepinephrine dilates and constricts blood vessels, making the genitals more sensitive. The body releases this during sexual stimulation.
* Oxytocin, also known as the love or bonding hormone, promotes feelings of intimacy and closeness. The body releases it after orgasm.
* Prolactin levels rise immediately following orgasm. This hormone might be related to reduced sexual response, which may explain the refractory period.