Subject: How does the electron gun fire into the picture tube of monitors?

The long appendage that comes out of the back of the picture tube is what 
I'm wondering about. I would like to know the process it goes through to 
take electrons from their orbit around copper atoms and "fire" them into 
the gases in the picture tube of a monitor. Also what reactions take place 
between the gases and and electrons that make the Red, Green, Blue 
segments of the screen work. Any answers to any part of these questions 
would be greatly appreciated.

Re: How does the electron gun fire into the picture tube of monitors?