Unless they talk to each other OR they have adcoms that do committee work for both schools, no. Some PA programs are under the School/College of Medicine, others are under Graduate Health Sciences. On the safe side, I'd go with the latter.
I'm interested as to see why you think PA programs are some sort of "back up" to medical school? If your heart isn't into being a Physician 100% (as in, you can't see yourself doing anywhere else,) then cut the bulls**t and just go for PA. If you want everything that comes with being a physician (good and bad,) then why waste time and money applying to PA school? Often, these programs are AS COMPETITIVE or more so than medical schools.