A professor at the University of Wisconsin was giving a lecture on "Involuntary Muscular Contractions" to his first year medical students.

Realizing this was not the most riveting subject, the professor decided to spice up his lecture.

He pointed to a young woman in the front row and asked, "Do you know what your asshole is doing while you're having an orgasm?"

She replied, "Probably deer hunting with his buddies."

It took 45 minutes to restore order in the classroom.