Why do my $PATH and /etc/paths Differ?

Why do my $PATH and /etc/paths Differ?

Typing export $PATH in Mountain Lion's Terminal returns
/usr/local/bin:/usr/local/heroku/bin:/opt/local/bin:/opt/local/sbin:/opt/local/bin:/opt/local/sbin:/opt/local/bin:/opt/local/sbin:/Library/Frameworks/Python.framework/Versions/Current/bin:/opt/local/bin:/opt/local/sbin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/usr/local/git/bin:/usr/local/MacGPG2/bin`
However, my /etc/paths file shows /usr/local/bin /usr/bin /bin /usr/sbin
/sbin
Is this a problem? Thanks!