The way we age

I find myself returning again and again to a New Yorker article by Atul Gawande, "The Way We Age Now." (PDF here). It was the subject of a May 2007 post which included a few clips from the article. His descriptions of the natural processes that underlie changes in teeth, hair, skin, bones, muscles, joints, etc during agin are the most concise and clear that I have read.