I just finished taking a grad level physiology--and I asked our teacher how much material we learned compared to what we will learn in medical school... It was very difficult & she told us that we only got 2/3 of the material and we had more time to learn it!
So, since I thought it was hard--and we only got 2/3 of what medical students learn... I am going to say take physiology if that is offered...
Looks like maybe not.... IMO, biochem lab would be helpful if you are interested in lab work, we did some basic assays in my biochem lab that translated to working in a molecular genetics lab. As for the others, the med students are WAY more qualified than I am.. but my two cents may mean a tiny bit...
Those listed below are relevant to what will be covered in med school...
Developmental Biology <--this would probably be helpful
Histology: Cell and Tissue Organization <--probably extremely relevant, but the others seem like they would be more helpful -- histo isn't so bad to learn for the 1st time
Endocrinology <-- This can get tricky at times; lots of material -- if you have a good teacher--you could be ahead of the game by knocking this one out
Introduction to Neuroscience <--hey, if it makes neuro easier in med school, go for it
Immunology <--this class can be really difficult if you don't have a great teacher, but if you do--it would be well worth it to take it now & have a knowledge base established for when you are in med school.