I use Crash Course Anatomy videos quite often in my A&P class. This is my write-a-long, or WAL as I call them, for their video on action potentials.
My WAL is broken into the sections shown within the video (intro, electricity 101, neurons, action potentials) and is mainly fill-in-the-blank. At the end of the video, I have students summarize the information in a drawing.
Please note that there is no key included with this product. It's good for you to watch the video so you know what your students will see, anyway :)