I hope you like this, I found it after following a link from a member on Thyroid UK (spareribs) for a thyroid video which was rather good.
This video encapsulates a lot of the research I have read, in a simple yet informative way.
Please look at the green diagram at the very end of the video - it is really useful and if I knew how to grab it and print it off I would - and beat my doc about the head with it