Every time you celebrate your birthday, as you blow out another candle on the cake, you find yourself another year older.
However, some of your body parts take little notice of the march of time and constantly regenerate themselves.
Take your intestines for example. They are constantly exposed to the corrosive stomach acid that breaks down your food. The cells that line your intestines need to regenerate themselves all the time to protect your gut.
Let's find out the age of some of your body parts: