From a ad for Genacol, Collagen types are:
Type 1 - Bones, tendons, ligaments, skin
Type 2 - Cartilage and structure of the eyes
Type 3 - Liver, lungs, arteries
Type 4 - Kidneys, other internal organs
Type 5 - Cells surfaces, hair, placenta
I'm definitely gonna give Genacol a try for my...