I just finished second year today, and I have to say hands down, that it was much harder than first year. HOWEVER...
First of all, this really depends on your school, and what you take each year. Here at Drexel, we take path, microbio, intro to clinical med (essentially pathophys), psychopath (this does not include neuroanatomy, which is a first year class), and pharm this year as our big classes. This excludes immunology, which we also took first year. If your school is anything like ours, I think that second year was more intense because it required more of a time committment to studying. A lot of our first year classes (physio, biochem, etc) were more conceptual, and if you didn't know an answer on an exam for example, you could possibly reason it out. On the other hand, just about all of the second year classes are like gross anatomy first year, where there is absolutely no reasoning going on, but instead rote memorization. This is what takes so much time second year. I could sit and learn physio for the first time much quicker than anatomy, where I had to committ details to memory just for the sake of mindless recall. So IMHO, I think second year was more difficult because I never really felt like I did anything but study. Now that I've just finished though, it's really easy to see the inter-relationships between the basic science disciplines, and I'm finally starting to feel like it's all coming together.... essentially second year got "easier" toward the end not because of the volume (which actually increased) but instead because I knew how to approach it (not to mention I no longer have to waste all my time looking up words like "empyema" or "claudication," which actually consumed quite of bit of my studying time during the first part of this year.... 😉
Good luck in your upcoming second year, and don't worry.... although it may seem like it at times, it's not impossible. Just put your time in and think of the long term picture (ie. the wards). Everything you learn in first year is a foundation for second year, but everything you learn second year is a foundation for the rest of your career, so (try to) enjoy....