Involuntary Muscular Contractions

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

Realising  this was not the most riveting subject, the professor
decided to lighten  the mood slightly. He pointed to a young woman in
the front row and said,  'Do you know  what your ass hole is doing
while you're having an  orgasm?'

She  replied, 'Probably fishing with his  mates.'

It  took 45 minutes to restore order in the classroom..........  .