gms | German Medical Science

Background: Laboratory classes traditionally form an important part of all healthcare-related curricula. In physiology, personal experiences during laboratories help students by visualizing the underlying, often complex, concepts. In the current pandemic situation, in-classroom teaching has virtually everywhere been replaced by digital teaching formats, which, however, cannot replace the benefits of well-established laboratory classes. Experimental designs, that can be conducted by students at home without supervision and medical equipment, are therefore strongly needed.

The baroreceptor reflex is a central element of cardiovascular physiology, which facilitates the upright position. But its teaching is challenging, as it integrates a broad range of physiological concepts which are per se difficult to understand (e.g. cardiac and vascular physiology, and neuronal feedback systems) and even more difficult to connect. Students greatly benefit from performing a Schellong test (aka active standing test) during laboratory classes. It visualizes the cardiovascular response by repeated measurements of blood pressure and heart rate during horizontal and vertical posture.

Question/objective: Here, we describe a practical course on the baroreceptor reflex, that can easily be conducted, analysed and interpreted by students during distance learning without direct supervision needed. We utilized a modified Schellong test, which was confined to measurements of the heart rate. Besides, we present the results of the experiments, quizzes and student’s evaluations.

Methods: This course was preceded by lectures and seminars on the baroreceptor reflex. Prior to the experiments, students documented their expectations. For the experiment, students only needed a stopwatch, a notebook and ~20 min of time. Subsequently, the experimental data was collected, students interactively interpreted their results and completed an evaluation form – all by use of an audience response system (e.g. mentimeter). This practical course was incorporated into the curricula of pharmacy, midwifery, dental, and human medicine with appropriately adapted quizzes.

Results: Within one year, data sets of ~200 students were collected. In this cohort upright position increased the heart rate from ~60 bpm to ~80 bpm (~30% increase), which agrees perfectly with the textbooks. Notably, only in 10% of the student’s heart rates raised less than 10%. Student’s evaluation showed very high levels of satisfaction.

Discussion: The modified Schellong test impressively demonstrated the effect of the baroreceptor reflex on the heart rate during vertical posture and made textbook knowledge come to life for the participants. This home-experiment is a feasible, learning- and cost-effective class, that can be integrated into all curricula, that lack in-classroom practical physiology courses. Besides, it offers the opportunity to aggregate experimental data of a whole cohort and present it to the students.