The nervous system, and the brain as a central part of it, is an essential part of our body. So much so that without it we could not live. It also plays a leading role in the outcome of the sexual act. But what exactly happens in our brain during orgasm? Why are there differences in the intensity of that pleasure between women and men?
During the sexual and physical stimulation phase and at the moment of climax, numerous areas and brain structures are activated. These, when bombarded with nervous stimuli from the genital area, stimulate the brain’s reward circuit and are responsible for us experiencing orgasm with all that it implies.
Phases of human sexual response
According to the Masters and Johnson models, people’s sexual responses can be divided into four distinct stages.
- Excitement: This is the moment when genital vasocongestion occurs. In other words, it is the beginning of the actual sexual response. In this phase, erection, lubrication, and elevation of the penis occur in men. In women, lubrication and enlargement of the clitoris occur.
- Plateau: This occurs only if stimulation continues. In these women, there is an additional enlargement of the penis and testicles. Their heart rate increases, their body temperature rises, breathing is faster and muscle tension occurs. In these women, there is greater vasocongestion, a reduction in the external diameter of the vagina, and an enlargement of the clitoris. Their physiological changes are similar to those of men.
- Orgasm: This is the moment of maximum general physiological activity and a great number of subjective sensations of immense pleasure. Men experience contractions in the anal sphincter, the prostate gland, and the muscles of the penis. Together with ejaculation and expulsion of semen, orgasm usually lasts between 3 and 10 seconds. In women, a series of rhythmic contractions occur in the vagina, uterus, pelvic muscles, and anus. Their orgasm can last up to 20 seconds.
- Resolution: This is the return to basal physiological levels. This is the so-called refractory period in men, during which they can’t achieve another orgasm.
The nervous system, the brain, and the orgasm
Despite all these physiological reactions described above, the organ that has absolute control over the presence or absence of orgasm is the brain. And its faithful companion is the rest of the nervous system. Without the sending of nerve impulses to the spinal cord and the brain, orgasms would not exist. Let’s see how the brain works during orgasm.
Nerve endings involved in orgasm
There are a huge number of nerves in the genital area, which send information to the brain about what the person is experiencing. Each of these nerve endings produces different effects on the person. There are more than 8,000 nerve endings in the clitoris alone! So, imagine the accumulation of sensations that a woman can experience and the number of processes that take place in the brain during orgasm!
These genital nerves communicate with other longer nerves that, in turn, transmit this information to the spinal cord. From there, they go to the spinal cord and ascend to the brain. The nerves that play a major role in this nervous transfer of orgasm are:
- Hypogastric: sends signals from the uterus in women and the prostate in men.
- Pudendo: generates nerve signals that arise in the clitoris in women and the scrotum (penis) in men.
- Vagus: Transmits from the cervix, uterus, and vagina.
Brain circuit of pleasure
When arousal begins, the brain starts sending blood to the sexual organs. It is a reflection of sexual stimulation, both physical and psychological, which is mediated by the parasympathetic branch of the nervous system. That is why the person must be relaxed.
Gradually, heart rate and respiratory rate increase in both genders. In this case, in the plateau phase, sympathetic activity predominates, producing important and similar physiological changes in women and men.
At the same time, as we have seen, the nerve endings in the genital areas and other parts of the body send signals to the brain’s pleasure circuit. Also known as the reward circuit this mechanism is responsible for classifying behavior as pleasurable or motivating. If there is continued stimulation, various brain structures in this circuit are activated.
Some of them are the amygdala (regulation of emotions), the nucleus accumbens (release of dopamine), the cerebellum (control of muscular functions), and the pituitary gland (release of endorphins or oxytocin).
Activation of other brain areas
In addition to the reward circuit, scientists have used a scanner to observe how certain areas of the brain act during orgasm. Thanks to this research, which has lasted more than 30 years, it has been revealed that brain activity is very similar in both genders and that there are no significant differences in sexual response.
In both cases, this causes inhibition of the lateral orbitofrontal cortex, the part of the brain responsible for reasoning and control processes. In this way, the brain completely shuts down this area during orgasm.
But in women, many more brain areas pause than in men, which remain active. This could explain the difference in the duration of this intensity of maximum pleasure between genders. In women, the central grey matter is also activated, which activates the fight-or-flight response. The cortex, involved in pain, is also stimulated, which could suggest an existing connection between this sensation and pleasure.
On the other hand, a study by Holstege has discovered the exact area of the brain that controls orgasm. The dorsolateral pontine tegmentum is in the brain stem. The research concludes that it is responsible for ejaculation and orgasm, with no differences between the sexes. Interesting, right?