MRI Coitus Anatomy

The best pics I have seen of the "MRI of erect wang actually in the vagina" — which I have seen in a couple places on this site — are at this link:

http://www.bmj. com/cgi/content … 19/7225/1596/F3

Furthermore, I found this image that really drives it home. It uses colored labels and cycles through 3 different images to help differentiate between what is what…

Well done commander.

I can just see two people inside the MRI donut with legs up and pressing together as much as possible when the guy says,”OK hold your breath”. I can imagine them trying to get everything in the same focal plane.

Oh yeah this is good.

I like this:
It says to the right as you read the opening page:

“Highly targeted related advertising ‘coming’ soon.”

Can you figure out where the cock is and where the vagina is? That looks a little bit like lower Charleston in the Carolinas to me.

But a good start, there, Cmdr. Nice going.

Ha! That is funny.

Not too easy to tell in the pics on that page I linked to. But did you see the image I attached to the first message? it is very easy to see the difference in the little animated GIF… the male and female are two different colors.

I’d love it if one of you Mods could make the image “inline” so you don’t have to click the link. :)

By the way, I sort of see a Bengal Tiger in the originals… I guess these Coitus MRIs are like Rorschach blots?

Thanks for this. I was thinking I had seen it posted here at Thunder’s before - I know I have seen it posted, or posted about, in some forum in the last few months - but I can’t easily find it in a search.

What I want to know is, what is the size of that penis?

Presumably that’s an average 5” - 6” penis - it could even be a bit shorter and not be fully erect, which would be consistent with what might occur during the conditions that such an image could be expected to be taken under - and it appears to me pretty clear that there’s not room for more than an inch or two of additional length without things getting extremely or even impossibly tight. I think that is very revealing.

FF

commanderblop, I’m glad that you posted this thread with the MRI image. For the last few years I have searched the Internet for information about the maximum depth of the vagina when aroused. While searching, I did come across this BMJ web page with the MRI images. The depth of the vagina was not given, but the distance between the male and female pubic bones was stated to be 4cm.

Some important things to notice in this image is that the penis arches upwards, or has an upward curvature during penetration.

The second important thing is that this woman has a RETROVERTED UTERUS. Her uterus is flopped over backwards with the end of it facing her tailbone rather than her belly. Here is an excerpt from inletmedical.org that describes the retrovered uterus condition.

“What is a Tipped Uterus?
A tipped uterus is the term used to describe a uterus that is tilted backwards away from the belly. The condition is also referred to as a retroverted uterus or tilted uterus. All three terms are interchangeable. The uterus is normally suspended in a straight up and down position or slightly forward toward the belly. A tipped uterus is usually something you are born with, but can be caused by labor while giving birth or by disease. It occurs in approximately 20% of women.”

Why is it important for members here to understand what a retroverted uterus is? Well, when having intercourse with a woman with a retroverted uterus, a man with a long penis will not be able to angle into the cul de sac (deep spot, or more correctly, the posterior fornix) for deep penetration. The tipped uterus will block deep penetration in that fornix from the outside of the vagina.

I am interested in making a couple of drawings depicting the anatomy of “deep penetration”. I would like to write an article with these drawings and post it to thundersplace. Dr. Robert Latou Dickinson wrote a book many years ago with information about the size of the vagina. A few drawings are in that book that depict anatomy during penetration.

I do like the animated color imaging of that MRI image. I did find that the image on the website was hard to understand. I had to focus and concentrate in order to identify the organs, and I have more experience with looking at cutaway images of the female pelvis than most people do. So, this animated image is great.

Take a look at the L5 lumbar. The edge of that lumbar that is closest to the woman’s belly is known as the pormontory of the sacrum. In theory, that is the deepest point that the end of the vagina will stretch up to. This may be painful for some women (most women), but women that enjoy deep penetration probably near this point. I believe that some men and women confuse hitting the vagina’s limit for depth, with hittin the cervix. Hitting either the deepest limit, or the cervix too roughly will cause pain. It is tough to put these things into words. I need to draw something.

Here is an image from that website showing uterus positioning. Notice is the normal postioning that the rear fornix, the posterior fornix, would not be blocked by the tipped uterus, and the penis would be able to stretch that fornix in deeper.

That MRI thing was posted here about four years ago, maybe even five years ago. A different lifetime.

No doubt. I have seen it many times at Thunders, and in many shapes and sizes.

But the inline version in the first pic is the best version I have seen. Very clearly illustrates what is what, IMO.

Thanks for posting that commanderblop.

Kojack10, that was very interesting and I understood what you were typing about the L5 being the deepest point that the end of the vagina will stretch up to. That explains why some women can take such long dildos, arms etc.

Something I found interesting in the MRI was the positions of the 2 pubic bones.
It really helps me imagine how if the man moves up using the CAT technique deeper and higher penetration would occur.
Especially when the tip of the male pubic bone is higher than the females, once this happens the angle of the male pubic bone allows him to push further forward.

Nice diagram.

I’d like to see a diagram of doggy-style penetration and anal penetration compared to this to see different areas of collapsation and expansion in the vagina.

The addition of the gif does indeed “drive it home.”

The subject in the film may have a totally straight penis. If I am not mistaken, this particular photo was demonstrative of the fact the an erect penis bends somewhat during intercourse, which you wouldn’t expect.

Now, what I can’t figure out is how they jammed those two subjects into a standard MRI tube. When I had an MRI of my leg, there was about 4 inches between the tip of my nose and the wall of the tube.

Thanks for reposting this. And to kojak for the info about a tipped uterus.

Avocet,

There’s a good chance they used an open-field MRI for this sort of procedure. Around where I live, there is the option to go to a special radiology clinic that has invested in a multimillion dollar open MRI/PET/SPECT imaging system. It’s a tiny bit more accurate and high tech than a regular one, but the main benefit is that you can get very large or claustrophobic people into it, and easily scanned.

Well, thanks for the feedback bluenun and Avocet. I was unsure that I had explained things clearly enough.

Yes bluenun, that explains why the vagina’s ability to stretch inward is more limited than its ability to accept massive girths.

Infact, the average distance from the lowest point of the pubic bone, to the promontory of the sacrum (the L5 lumbar) is 12.5 - 13cm on average (that measurement is known as the diagonal conjugate), which just so happens to be the average maximum aroused depth of the vagina. Many studies, not just one, came up with that same average. Before anyone does the math, that was taken from the remnants of the hymen to the deepest point, not from the outer edge of the vulva/lips. The vulva averages 2.5 cm or 1” in depth. If a woman’s body changes, and she becomes slightly deeper after pregnancy, it is not just that she stretched more inward, but actually because her pelvic floor, her openings may have lowered slightly.

Thunder, you are right. Looking at the bottom of this page at the list of “similiar threads”, we see that sailboatracer posted a thread with this image. I believe that I also posted a link to the BMJ page on one of my vagina size threads, but I just figured that I’d spread a little info on this thread also. I understand though, the repeat threads can add up and take up space.

Yes, that explanation and the posting of the MRI has been a real eye opener for me, makes things so much clearer.
I must have missed the previous threads on this subject.

If you do decide to write an article and post some drawings I think many here would find them of interest.

So with the Vulva and the diagonal conjugate 6 inches on average should be enough to stimulate the posterior Fornix?

I agree with Vater about wanting to see an MRI of the doggy-style position.