Head voice in men is produced in the same way as it is in women.  I have studied hundreds of scoping videos from otolaryngoloists and found that it looks the same.  We tend to call the whispy head voice "falsetto," but a plummy head tone with well-approximated vocal folds and no noticeable air loss "head voice," but the reason why escapes me.  Men and women have the same vocal problems, like the whispy voice.  You find it in women's high voices oftentimes and in men's more often.  We just tend not to train a man's high voice.  It all works the same.

 

This guy goes back and forth constantly in this video. http://www.youtube.com/watch?v=Q-PZlj0UH0c

You use two major muscles to determine pitch: the thyroarytenoids and cricothyroids.  Throughout the "modal voice", which covers the majority of our singing, we use both of these muscles to varying extents, with the thyroarytenoids dominant in "chest voice" and the cricothyroids dominant in "head voice" but still both muscles being used throughout.  When you let go of the thyroarytenoids entirely (the more chesty muscle), you get falsetto in a man, or sometimes called flute in women.  When you let go of the cricothyroids entirely, you get vocal fry (lowest register).  According to some of the vocal pedagogy books I've read, you can also take the high range a step further in addition to disengaging the thyroarytenoid, by damping the back of the vocal folds to shorten the vibrating length, to create a "whistle" register.  However, I have no experience with this last and can't provide much more information into how this is done.

Now, actually putting that into practice to create those sounds is a whole different story, because I can't directly feel in my voice box and say "oh, that one's my thyroarytenoid".  But that's the anatomy of it.