How do you re-source the environment variables in a command prompt in Windows?

In a bash shell, you can edit your environment variables, run source ./.bashrc and refresh the values of environment variables in an already open shell. Does Windows have a similar command that you can run to do this from the command prompt?

(for instance I might change my system %PATH% variable in the properties of Computer, and then want my existing cmd.exe window to refresh the environment variables from there.