“Graph's disease” and students' anxieties in understanding physiology

Graphs are visual summaries that explain the phenomenon in different disciplines. Students who approach physiology in rote-learning mode usually have more difficulty and anxieties to understand the graphical information. Graphs can be used in many ways to conceptualize much of physiology. The relationship between the X-axis and Y-axis variables can indicate a cause and effect scenario as in the hemoglobin-oxygen association/dissociation. Temporal, sequential events are illustrated with the X-axis as the time parameter and several changing parameters can be followed along the Y-axis in a dynamic way as in the Wigger's cardiac cycle diagram. Graphs can also provide a different perspective on the fluctuations between two parameters that is produced by a third physiologic event as seen in the ventricular volume-pressure loop. Hopefully, this article on physiological graphs will help students to relax and enjoy looking and thinking through the different line profiles in graphs they face in their “Physbook.