Perhaps, if like me, you’ve googled the science behind orgasms before and have been baffled by the complexity of it all, you’re in the right place to get a quick guide into the biology of an orgasm.
We’ll start with the male orgasm – an arguably simpler and more straightforward affair. We all think of this as just ejaculation, but males can orgasm purely from stimulation of the prostate alone. But I will focus here on the average male ejaculation. The parasympathetic nervous system is essential for getting an erection by causing the trabecular arteries in the penis to expand. This response can occur in your sleep – hence a wet dream – but this usually only occurs due to a sexually stimulating dream. Interestingly, sight, memories and imagination play a far greater role in sexual stimulation in males than in females, and alone are potent enough to ejaculate from.
The spinal ejaculation centre at the base of the spine cause semen, produced in the testicles, to pulse through the urethra which is ejected in rhythmic contractions. The average male produces seven spurts of semen at speeds of up to eleven mph. One study claimed that the longest distance a male can ejaculate is six feet, but from my humble experience, I would take that with a pinch of salt.
During the orgasm, the hypothalamus and pituitary gland releases a wave of prolactin, vasopressin and oxytocin, with the latter involved in emotional responses and which can give feelings of love. Coupled with testosterone release during stimulation, the cocktail of hormones also gives the classic male trait of falling fast asleep right after ejaculation.
Unlike men, women are capable of eleven different types of orgasms. Whilst we are all familiar with the classic clitoral and G-spot orgasms, women are capable of non-vaginal orgasms from stimulation of the nipples or anus. Interestingly, a study in the US found that 69 percent (very unfortunate number for this statistic) of women reported they had experienced a mild orgasm during exercise. During a vaginal penetrative orgasm, the clitoris expands as the woman gets nearer to climaxing due to increased blood flow. A series of muscular contractions then occurs throughout the vagina at the point of orgasm, coupled with a pleasurable sensation. Biologists have worked out that these contractions aim to push semen into the uterus. Female orgasms last longer than males on average, and as women have no refractory period after they climax, they are able to orgasm again straight away.
Women experience a release of prolactin and oxytocin upon climaxing, coupled with increased activity in two areas of the cerebral cortex associated with emotional processing. It’s suggested that these two areas enable women to double their pain threshold during orgasms. They also have the potential for greater pleasure than men, with the clitoris having 8,000 nerve endings – twice as much as the head of the penis.