• What causes “pins and needles”?
  If a nerve gets squashed, it cannot carry nerve signals. If you kneel ...

• What does the brain look like?
  The brain looks soft and grayish pink. The top is wrinkled like a ...

• Why do old people have gray hair?
  Some people's hair stops making melanin as they grow older. ...

• Why does skin have pores?
  Skin has tiny holes in it called sweat pores to let out sweat and ...

• What is goose flesh?
  Goose flesh is bumps on your skin formed by the tiny muscles that ...

• What are freckles?
  Freckles are small patches of darker skin made by extra melanin. ...

• What is a tendon?
  A tendon is like a tough rope that joins a muscle to a bone. If you ...

• Which is the strongest muscle?
  The strongest muscle is the one that shuts your mouth! It is called ...

• How many muscles are there?
  You have about 650 muscles that work together. Most actions-including ...

• What is a reflex action?
  A reflex action is something you do automatically, without thinking ...