Magnetic Resonance Imaging of Human Coitus

Found this not-so-recent paper mentioned in Serene's blog.

In brief:

What is already known on this topic

It has been extremely difficult to investigate anatomical changes during the act of coitus and the female sexual response

Modern magnetic resonance imaging allows exploration of aspects of living anatomy

What this paper adds

Taking MR images of the male and female genitals during coitus is feasible

During `missionary position' intercourse the penis has the shape of a boomerang

During female sexual arousal without intercourse the uterus rises and the anterior vaginal wall lengthens

The size of the uterus does not increase during sexual arousal

Even more interesting are the authors' responses to this paper.

Copulating for the sake of science. Hmm...The results are interesting, although the MR tube had rather limited space. Then again, they could only investigate one type of position (missionary) with the room they had inside the equipment.