Quote from Dwight K. Schrute in Blood Drive
Dwight K. Schrute: Having trouble finding a vein? Nurse: Yup, a little. Dwight K. Schrute: How about now? [aside to camera:] Dwight K. Schrute: I've trained my major blood vessels to retract into my body on command. Also, I can retract my penis up into itself.