Guts or Balls - A Medical Distinction

We've all heard about people having guts or Balls, Medically here is the the difference ? 

  GUTS - Is arriving home late after a night out with the guys, being met by your Wife with a broom, and having the guts to ask :'Are you still cleaning, or are you flying somewhere?' 

BALLS - Is coming home late after a night out with the guys, smelling of perfume And beer, with lipstick on your collar, slapping your wife on the butt and having the Balls to say: 'You're next, Chubby.' 

Medically there is no difference in the outcome.  Both result in death.