View full lesson: ed.ted.com/lessons/why-do-our-bodies-age-monica-menesini Human bodies aren’t built for extreme aging: our capacity is set at about 90 years. But what does aging really mean, and how does it counteract the body’s efforts to stay alive? Monica Menesini details the nine physiological traits that play a central role in aging. Lesson by Monica Menesini, animation by Cinematic.