Starting with the 4th printing of the Anatomy and Physiology textbook, there were changes made to several sections which were more extensive than are typically made.  If you are using the 1st, 2nd, or 3rd printings of the textbook, your textbook will not match up completely with the audio since the audio reflects these changes.

The following document lists the updates to the Anatomy and Physiology textbook that are included in the audiobook:

Revisions