If I recall, there was only one essay on the secondary. The rest of the application consists of filling out lists of activities (academic, non-academic, volunteer, work-related etc.) and giving the time spent in those activities and a brief description of them.
The essay that I had was something like...
"Tell of something that you have found to be difficult in life and how you overcame that difficulty. How has this better prepared you to be an osteopathic physician?"
If I remember correctly, that should be about right.