A man comes home. He is thirsty. The inside of his mouth is dry. He pours a glass of water and drinks it down. The water is cold in his throat. It hits his stomach and does not stop.

An empty stomach lets it pass right through to the gut-The work begins there. In the first five minutes, some of the water is already moving-It goes through the walls of the gut and into the blood. The blood starts to move it around the body. His brain gets the message that water has arrived, so the man does not feel so thirsty anymore. But that is only the start.

The rest of the water follows, pulled into the blood over the next hour, the blood gets what it needs-The kidneys get their share. Then the water goes to the dry cells. They take it in slowly-The whole job, from the glass to every cell being full again, takes almost an hour.