Physiology is one of those subjects where you actually have to UNDERSTAND what's going on. Unfortunately, a quick flick through lecture slides before the MST or exam won't do. There is a fair bit of memory work as well, but its mainly focused around the concepts, some which take time to truly understand and appreciate.
I found the best way to study Phys was to watch lectures, readings, YouTube things that were unclear. Once you think it's clear try explaining the concept to yourself (or your friends, family whatever, better with friends). If they can understand what's going on then try thinking about what happens if you play around with physiological conditions. Then try fitting it into the bigger picture (everything's really integrative in physiology).
Also try doing as many questions as possible (silverthorn has a few), if you got the answer right, check if you got it right for the right reasons (or just took a random guess lol). If you got it wrong, check out where your reasoning went wrong. Once everything falls into place and makes sense, you'll love it (I did, especially the nervous system phsyiology hence my decision to major in neuroscience).
Heads up lads ! Our PHYS cohort was in the same position last year with more than half of us failing the first MST (worth 15%), we ended up being one of the better cohorts at the end though. Even if you get a 0 on the test (highly doubt anyone did lol) you can still get a H1- quote by Charles.