As is well known, I'm somewhat conservative about what I think we ought to show in Wikipedia. The bounds of good taste are very important.
Having said that, I think that the current article and diagram/photo are not problematic. This is very different from the 'clitoris' picture (don't know the current status on that one), which looked "like porn" to me -- in poor taste.
The diagrams and photo in this case are very "textbook" looking.
As to whether this sort of thing should go into a version of Wikipedia intended for distribution to schools is perhaps a different matter, and one that we will have to address specifically at some point in the future.
--Jimbo