Should I read from journals or textbooks?

Ok. This one is difficult to answer because educators tend to feel that at university level students should be reading mainly or at least as much as possible from original sources ie journals.
But I think an exception should be made for medicine.
Typically most medical students will cover about 20 main /core subjects over a 5 year period. In addition to this they will have a large number of practical classess / clinical sessions. All this adds up to a huge amount of time.
Firstly not being a doctor yet, it is likely that you will not have a clear idea about the area you want to cover and to the depth of knowledge you will need.
To try and satisfactorily cover a topic just by reading journals is a time consuming and tedious task, not to mention your that your medical library will probably not subscribe to every single medical journal! This will invariably lead to "gaps" in your knowledge.

So in this instance my advise would be:

• Read a small concise textbook before the lecture class- this will give you an overview of the entire topic quickly
• concentrate during the lecture class/ practicals etc- these tend to give you a broad outline as to the area to be covered, important topics and the depth of knowledge needed.
• Read a more detailed "standard/ recommended" textbook.
• Practise writing out answers for past year questions-not necessarily only those from your medical school.

Pick a few oft repeated questions and do a bit of journal reading on this. If you do happen to get asked these questions especially for a viva-voce you will be able to impress the examiner!