This POGIL-style lesson is a self-guided activity that allow students to identify the four chambers of the heart, the major blood vessels (vena cava, aorta, pulmonary artery, pulmonary vein), and the pathway of blood flow in systemic and pulmonary circulation. A great way to introduce a rather complicated topic. I found that this self-guided activity takes about 20 minutes, and minimizes the amount of time I need to spend lecturing. Follow up this inquiry activity with a 10 minute overview of circulation, and your students will have a strong understanding! It also would make a great homework assignment so that your class comes in with basic understanding.