Why does maps of the CMB not show the Milky way?

I have looked at some maps of the Cosmic Microwave Background, such as the one in the Wikipedia article on the CMB:
http://ift.tt/2kiviEd

I wonder why the Milky way is not visible as a smudge across the cosmic equator. Do these microwaves pass right through a galaxy without being absorbed in any way?

via International Skeptics Forum http://ift.tt/2kF3Myv