Normal body temperature is about 98.6°F (37°C), but this can change. In this article, we look at normal ranges in adults, babies, and during pregnancy.

Each kidney contains millions of nephrons, making this vital organ one of the heaviest in the body: about 4.5 to 6 ounces (125 to 170 g) in male adult and from 4 to 5.4 ounces (115 to 155 g) in ...

And it sends signals to your body that let you do what you want, like moving and talking. The brain alone has more than 100 billion neurons to send and receive these signals, or messages.