An Inexpensive Portable Concept Map for Studying and Learning Regulation of Blood Pressure

Abstract

Background Regulation of blood pressure (BP) is one of many physiological endpoints regulated by a nexus of autoregulatory, neural and hormonal mechanisms. BP is directly dependent on cardiac output (CO), vascular peripheral resistance (VPR), and blood volume (BV), but can be altered by a network of neural, hormonal and cellular mechanisms that directly or indirectly modulate any one of the three primary determinants. Students have difficulty comprehending this expansive mechanistic network with diverting and intersecting effects, e.g., the renin-angiotensin-aldosterone system that modulates both VPR and BV. Digital learning resources are valuable tools, but can be expensive, require reliable internet connection, and may not be used on exams. Objective To develop a non-virtual portable tool for learning the regulatory network for BP that was 1) crafted by the student from inexpensive materials, 2) easily modified and expanded to incorporate various mechanisms as introduced in lecture, and 3) readily constructed and dismantled for self-testing and easy transport. Approach A portable and revisable concept map was developed over several semesters with multiple student groups. In preparing for the cardiovascular (CV) section, a list of all components in the regulatory network for BP was made with BP, CO, VPR and BV as the first terms. The CV section began with fundamental descriptions of the closed circulatory system comprised of the heart, vessels and blood and the essentiality of regulating BP to ensure blood flow sufficiently matches metabolic needs of tissues. Students were shown the entire regulatory network on one slide and assured that during the CV section they would learn how all components work together and be able to recreate the network themselves and ultimately, use it as a study aid. To get them started, students received the list of CV terms and several small pieces of paper, e.g., 2”x2” plain paper squares, 3”x5” cards cut in half, standard Post-It® notes. The instructor explained that when they learned a new mechanism they were to write the term on one side of the paper and the definition and pertinent information on the other in pencil for easier editing. Then the instructor arranged her own set of BP, CO, BV, VPR and other terms on a white board to show the map of functional relationships take shape. As new concepts were discussed, e.g., CO = Stroke Volume (SV) x Heart Rate (HR), the respective terms were added to the map to reflect the physiological relationships. She explained their map could be laid out a table, floor, etc. While studying alone or with study partners, students were encouraged to audibly define terms and relationships among mechanisms as they constructed their maps. They were encouraged to shuffle terms and recreate subsections of the network to understand mechanistic connections at different points in the network. Effectiveness of the tool Students expressed that manually arranging components helped them better comprehend functional and consequential relationships among different mechanisms. The tool can be used to also learn other regulatory networks, such as those of the digestive system and calcium homeostasis.