Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Linear Decline in Multiple Organs Exponentially Decreases the Area within Which Perturbations May Be Restored as Shown Here for Two Organs. Reprinted with permission from J.F. Fries and L.M. Crapo, Vitality and Aging (San Francisco: W.H. Freeman, 1981).
