Hi SLP2B111!
I majored in Communications Arts (basically illustration) at Virginia Commonwealth University, where you can specialize in scientific and preparatory medical illustration. I also had a minor in Biology. Many people will be applying having the same background as you! It's about half art majors and half science majors.
My main tip is to contact the program(s) you are interested in and see what else you need to do to be ready to apply. That will also get your name out there. Make sure you complete those science courses and that you do really well in them! Many schools offer a chance for you to go and show your portfolio. They will give you great feedback and tell you exactly how to improve. Have as many people as you can critique your art! And make sure you don't submit anything too "medical" in your portfolio, because the programs don't want to see that.
Take some time also just to research the career and see art from alumni of the programs. Nothing is more inspirational! I wish you the best of luck. I can answer any other questions you have, though I didn't apply to UIC, so I only know about the other programs!