Rib Cage. In an adult human, the rib cage has 24 bones and the hand 27 bones.

Using A Fluoride Toothpaste. Fluoride has been shown to help prevent cavities in teeth and was first added to a toothpaste in 1914.

Jonas Salk. The polio vaccine passed field tests and was first administered to the general public in 1955.

Butterfly. The thyroid is the largest endocrine gland in the body.

50 Million. Epilepsy is a chronic disorder of the brain which is characterized by recurrent seizures as a result of excessive electrical discharge in brain cells.

20%. According to the World Health Organization, about half of mental disorders begin before the age of 14.