I can't comment on it due to its age.
Well, it helps to use bigger text in the body on the intro sentence like this:
The vagus nerve controls involuntary body functions.
I mix up my smaller text with bigger ones to help people not get bored with my writing.
Also, you can always start your beginning sentence with a question or some shocking detail. That grabs people's attention.
Wow..these do make a huge difference! right, will have to practice doing them, seem easy enough ;) Many thanks.