Ok so I had the lecture on this yesterday and my test is on Monday, I tape recorded the lecture and have listened to it over again but I'm so confused. When they go over the different pressures cvp, rap, rvp, pam, pawp etc... I can't keep all the meanings together and understand this at all. This is my second test and I didn't do so well on my first one so if I can't grasp this I think I'll be done for. I'm trying my hardest and have put hours into researching this topic but I feel so stupid because I can not grasp it. Any help would be appreciated.