Each medical school has its own set of feeder schools. Which med schools do you particularly care about?
OTOH, if you want to know where you might have an "in" based on your own undergrad institution, ask your premed advising office/official at which med schools their population most commonly gets an acceptance.
Feeder schools only have meaning in the context of a specific medical school, or a class of medical schools. For instance, the top undergrads are obviously feeders into the top medical schools - some more so than others. At the top schools, the schools' undergrad programs are also big feeders into their own medical schools. This is where going to a place like MIT or Princeton might be disadvantageous because there's no "home field" advantage when applying to med school.