The Things I Understand and Don't Understand

In Physiology and Anatomy class, I am beginning to understand how the class works. I also understand the things that are taught like how different cells have different shapes and sizes due to their different jobs. I also learned the eleven organ systems like respiratory, cardiovascular, digestive, reproductive etc.
Things I do not understand about the class is that sometimes assignments are posted on the class website or Edmodo and the assignments were never explained during class. I think I need more information in order to do a better job in class. Many of my grades have been dropping in class because of miscommunication and because I don't understand what's going on in class. Also, we recently went through the bone landmarks. I did not get the bone landmarks because the whole lecture went by so fast for me.