Health Trivia Quiz

What is sleep training?
How many carpal bones do you have?
16, 8 in each hand.
How many muscles does it take to smile?
Absolute minimum of 4, but for the full answer:
What does a nose do?
    It 1) holds up eyeglasses, 2) smells odors, 3) conditions inhaled air, warming it and making it more humid,         4) hairs inside the nose prevent large particles from entering the lungs.
What substance are nails made of?

What is the colored portion of the eye which controls the amount of light which enters the pupil called?
    The Iris.