Pathology

Pathology is very important for Paper A, also considering it binds to physiology. You need to have a strong grip on pathologies.

Use First Aid to make core concepts, and then revise with help of these notes. I would say depending on which exam you sit in, they focus more on certain topics. My exam focused more on cellular and hypersensitivity reactions (There were whole scenarios asking what HSR is this).

But i would advise to cover all of these basic topics to be prepared for the exam. Some questions still come out of our domain which is hard to cover, but having a general idea of basics gives you an edge to select answer based on an educational guess.