Hey! it's been a while again. but this time I really did a lot of study on the topic, as they are in my semester as well. three years back, I didn't understand how and where the blood is pumped by the heart and over time it became harder. so this time I took the goal of understanding from the very basics. if you can get the functional part understood, than you would have a easier time incorporating other information. hope this helps. try to visualize things over and over in your head as you listen or read about it later. things would become easier.