Costanzo's BRS Physiology is an awesome text for review and organizing the concepts, but if you're new to physiology, you're going to need to refer to other sources.
During our cardiovascular block, I had a hard time finding good resources. I read the cardiovascular portion of Berne and Levy Principles of Physiology, and it clarified things quite a bit. Read those chapters if your school notes aren't enough for cardiovascular physiology.
For Pulmonary, I read some chapters in Michelle Cloutier's Respiratory Physiology to help clarify things.
For Acid-Base, Benjamin Abelow's Understanding Acid-Base was great.