The Wiggers diagram showing simultaneous events of the cardiac cycle in composite graphs is one of the most intimidating figures students encounter in their study of physiology. This paper describes a discovery learning activity that walks students through the construction of the Wiggers diagram by focusing on the core concepts of blood flow down pressure gradients and the structure-function relationship of heart valves and one-way blood flow through the heart. Additional tasks require students to transfer their understanding to previously unstudied scenarios and figures, such as the left ventricular pressure-volume loop.