Skeletal: Silence Muscular: being patient Cardiovascular: doing it's job Nervous System: nervous Digestive System: Oh gosh.... Reproductive System: Working Respiratory: breathing Immune system: fighting your sickness Lymphatic: helps Immune Urinary: cleaning blood Endocrine: he's never tired Integumentary: bored the Doctor is sleeping, also, the Systems can hear you, but you can't hear them