http://home.ican.net/~thyroid/English/Guides.html
Multiple links to websites concerning thyroid conditions. Pictures are available on some of the sites.

http://www.cs.sfu.ca/css/update/vol8/8.1-muscles.html
This site explains the effect of insulin-like growth factor (IGF) on muscle cells and relates this effect to aging. A clear drawing explains the roles of receptors and carrier molecules in this process.