What biologically causes the pleasure associated with an orgasm?

September 2, 2008 5:46 PM

What are the underlying processes occurring during an orgasm that are the biological causes of the pleasurable sensation we associate with it? Is the sensation of orgasm a function of the nervous system, or is it something neurochemical in the brain, or both, or neither? Is the reason that certain masturbatory and/or sexual acts feel good because of nerve concentration in the erogenous areas, or is it something different or more in nature?

I'm primarily interested in answers relating to the male orgasm ... as I expect the male orgasm and the female orgasm may have different biological processes given the different anatomy?

And just to ward off any wisenheimers, I obviously understand the idea of Act A produces Obvious Biological Result B and Happy Sensation C. What I'm curious about is the underlying medical process behind that equation.

posted by WCityMike to health & fitness (9 comments total)

It's a neurochemical thing- make it pleasurable and we will seek out that pleasurable act. And fill the world with our spawn!

In other words, the physical act of love stimulates a deep down pattern recognition instinct in our nervous system. For the race to survive, there needed to be something instinctual that "taught" us to fuck like rabbits. So when that pattern starts to emerge in our brains, our brains respond by "turning up the volume" on those sensations to reinforce those behaviors via neurochemical stimulation.
posted by gjc at 5:57 PM on September 2, 2008

Not to poop on your question, but isn't this best answered by textbooks or at least scientific articles, and not by a community like AskMe? I mean - your question is worded in a very scientific way, so it seems clear you're looking for a scientific answer...

The Wikipedia article for Orgasm is incredibly thorough, and even has the answers to your question broken out -- all the way down to physiological response in men and in women...
posted by twiggy at 6:14 PM on September 2, 2008

Yes. I actually read the Wikipedia article before asking this question. But what causes the actual sensation of pleasure doesn't appear to be addressed.
posted by WCityMike at 6:24 PM on September 2, 2008

> isn't this best answered by textbooks or at least scientific articles, and not by a community like AskMe?

Plus, we have doctors who are AskMefites, as well as people who just seem extraordinarily knowledgeable about this stuff.
posted by WCityMike at 6:28 PM on September 2, 2008

I think you're confusing yourself a bit by separating out the pieces from the whole, WCityMike. The brain is a part of the nervous system, and they function together to help create what we experience as orgasm. It's affected by the spinal cord, the brain, the nerves at the site of stimulation, and several different glands. I'm juggling a few things right now, but you might want to take a look at The Science of Orgasm.
posted by StrikeTheViol at 7:41 PM on September 2, 2008 [1 favorite has favorites]

Seconding StrikeTheViol's comment here, and noting that your question either gets one of the straightforward answers you probably got from the Wikipedia article or leaves the arena of neuroscience altogether. If you're simply asking which neurological processes occur in the phenomena we label "orgasm," then those sources you've already seen give you the best scientific answer there is at this point. (One that should improve with time and research.) If you're asking, "Okay, I understand that it's neurlogical processes x, y and z, but why do processes x, y and z appear to us as pleasurable sensations rather than searing pain? What makes those neurological phenomena feel that way rather than some other way?" then you are walking straight into the hard problem of consciousness. If you present practicing neuroscientists and doctors with that question, most of them will shrug their shoulders and send you down to talk to us in the philosophy department, assuming they think you're asking them an intelligible question at all.
posted by el_lupino at 9:05 PM on September 2, 2008 [1 favorite has favorites]

Yes. I actually read the Wikipedia article before asking this question. But what causes the actual sensation of pleasure doesn't appear to be addressed.

Hmm. I wonder if you may be focusing too specifically on orgasm, then, and maybe should widen the scope to "what causes the pleasure sensation in general." Because a lot of OTHER things trigger that reaction as well -- not the same variety of pleasure, sure, but it's pleasure nonetheless.

And if your question is "what causes the actual sensation of pleasure," well, the one thing missing from the Wikipedia article is the particular description of the "pleasure" neurochemical reaction, and...that's not specific to orgasm. Certain drugs can trigger that bio-neurochemical response, and other sensory input can do so as well. So you may need to be focused more on the nature of the neurochemical response of pleasure itself, and may want to separate it from the cause.
posted by EmpressCallipygos at 9:07 PM on September 2, 2008

The wikipedia article on orgasm does not really discuss the psychological and neurological basis for why it is so pleasurable. You will need to reference the wikipedia article (or, if you're more serious, a neuroscience textbook) on the limbic system (see: The Limbic System from Purves' Neuroscience text).

The limbic system is what takes the signals produced by the five senses and integrates it with past memories, emotions, thoughts, etc. to produce an emotional response. The reward pathway is then activated to produce the feelings of pleasure. Dopamine, a neurotransmitter, is involved.

Not coincidentally, this reward pathway is what makes certain drugs so addicting (i.e. cocaine).
posted by scalespace at 9:50 PM on September 2, 2008

Seconding reading a 'neurobiology of sex' textbook. Believe it or not, there are entire graduate courses centered on the question you ask.

Short answer is, it's all about the limbic system and reward centers. The activities between the legs yield dopamine release between the ears, and voila, pleasurable sensations. In rats, the key brain regions are the medial forebrain bundle or nucleus accumbens. In humans, it's a bit more complicated. Google 'fmri orgasm'.

It's possible to decouple the physical orgasm (i.e., ejaculation) from the sensation orgasm (i.e., OMG!). The former is mediated by neurons in the spinal cord, while the latter is mediated by the brain. Some paraplegics have interesting stories about this.
posted by oceanmorning at 10:21 PM on September 2, 2008 [1 favorite has favorites]