so basically the way an organ based curriculum works is that your units and exams are broken down by organ. For example, during the GI unit you learn everything about the GI. By everything I mean you are learning the physiology of the GI system, learning the histology of the GI system, dissecting the GI system, etc.
At some schools all of these subjects(by "subjects" i mean physio, pharm, path, histo, etc.) are separate. For example, at UCSD anatomy is a 10 week course and you dissect the whole body in 10 weeks and their dissections dont necessarily coincide with the appropriate organ so they may be getting lectured about the brain but may be dissecting the bladder, whereas at NU we are dissecting the brain during the neuro unit where we are learning the physiology of the brain. At non organ based schools they may be learning about the physiology of the pancreas in their physiology class and learning about the pharmacology of the kidney in their pharm class.
So organ based breaks down its units based on organ system whereas non organ system breaks down its courses based on subject(ie, physio, pharm, path, histo, anat, etc.)
i like the organ based system because u learn everything about a particular organ so all the relevant informationabout the heart(by relevant info i mean u are getting the physio of the heart, dissecting the heart, pharm, path etc.), for example, is integrated together. I think it gives a better big picture view of what you are learning.
For people having trouble understanding the differences I hope that helped somewhat.