Research shows that one of the most potent forms of retrieval practice is testing. The more you repeat the testing, the stronger the brain connections (synapses) involved in remembering that particular information get. Stronger synapses mean better recall and longer-lasting recall. In other words, repeated retrieval practice gets everything into your long-term memory, so you won't forget it by the time you get to the A&P exam—or when you need it all later in your clinical courses and career.
So when your professor tests or quizzes you, they do not just measure how much you know—they also strengthen your ability to "keep" all that knowledge for the long term.
One of the easiest ways to put retrieval practice into your study routine is to answer the chapter questions in your textbook. I know that unless the prof assigns them as graded homework, most students just skip those textbook questions. Too bad, because they are one of the best ways to learn!
Researchers who study learning have clearly shown that rereading your chapter over and over doesn't do a thing to reinforce your learning. Of course, you have to read the chapter at least once, but testing yourself on the material works way better than rereading the chapter—or your notes—again and again.
The spacing of your retrieval practices is critical for effective learning, too. So do your self-testing for short stretches, but frequently. Every day is best if you can manage that.
Don't get discouraged if you don't do very well the first couple of times. That's expected. I realize it's more fun to see immediate progress. But when it's too easy, you're not learning for the long term. You want to struggle—even forget some of it a few times—so that your brain gets a good workout. No pain, no gain. Eventually, you'll get better.
With repeated practice, practice, practice of information retrieval by spaced testing, you'll be learning more deeply—and more permanently.