the annual Intermedical School Physiology Quiz (IMSPQ), initiated in 2003, is now an event that attracts a unique, large gathering of selected medical students from medical schools across the globe, as previously described in this journal (4).
The 8th IMSPQ, in 2010, hosted by the Department of Physiology, University of Malaya, in Kuala Lumpur, Malaysia, had 200 students representing 41 medical schools from 14 countries participating in the annual quiz, in which two-thirds were overseas teams, including 4 teams from China and teams from 5 Indonesian universities and 5 Thai universities (Table 1). Newly competing teams from Romania, Europe, and Saudi Arabia also participated in the 8th IMSPQ. The challenge trophy for the IMSPQ is named in honor of the late Professor A. Raman, who was the first Malaysian Professor of Physiology at the University of Malaya.
From this international sample of medical students, we were interested in observing some of the common mistakes that were made by a significant portion of these students. We report here some illuminating insights gleaned from this international physiology quiz event. This report also highlights some common misconceptions among students of physiology, as has been previously described in definite studies by others (5, 8, 10, 13, 14).
Mechanism of the Quiz
The IMSPQ is a 2-day event, with a written test on the first day to rank the teams for the second day oral competition before a live audience of students and staff. Teams comprise a minimum of three to five medical students. Students participating from countries where English is not the first language were selected based on both their academic merit in physiology as well as their proficiency in written and spoken English. These selected students, representing their respective medical schools, compete in the written test. There is no elimination of teams after the written test on the first day. The written scores are used to rank the teams, as previously described (4), and they are grouped accordingly for the oral competition on the second day.
Among the 100 true/false (T/F) multiple-choice questions (MCQs) in the written test on the first day, all systems in physiology were tested, and, on average, 15 statements were asked for each of the basic major organ physiological systems (i.e., respiratory, cardiovascular, endocrine, renal, and gastrointestinal) as well as core topics (such as nerves, muscles, and blood).
The T/F MCQs posed in the written test were designed and vetted with the aim to maximize the testing of key concepts or fundamental understanding of physiology rather than to merely showcase skillful recall of memorized descriptive facts (1, 3, 15). To discourage blind attempts or guessing, negative marking was used (2, 7, 9).
On the evening of the first day of the quiz competition, a Concert Night is enjoyed by all IMSPQ participants, featuring multinational cultural song and dance performances by the participating medical school teams. This event helps showcase the many talents of the teams and helps foster camaraderie among the quiz participants.
Observation of Responses to IMSPQ Questions
Examples of the statements used in the 8th IMSPQ are shown in Table 2. These 21 statements elicited the majority of the incorrect responses among the 200 medical students. As an illustration, for 6 of the 21 statements, the concepts required for giving a correct response are shown in Table 3.
Interestingly, from the incorrect responses in the T/F MCQ test, we were able to detect common areas of misconceptions among this large group of international medical students. For 21 of the 100 conceptual statements, 40–70% of the students responded incorrectly. Of note is that these are mistaken answers from preselected students representing their respective medical schools. The item analysis done on the MCQ test as well as for each university team member's responses to the questions tell us which physiology concepts are universally more easily grasped and which are not.
Seventy percent of the 200 students responded wrongly to the statement “The glomerular filtrate concentration of inulin is ‘always’ less than the urine concentration of inulin” (Table 2, true statement 1). From experience in the Faculty of Medicine of the University of Malaya, students rather frequently confuse “filtrate inulin concentration” (in mg/ml) with “filtered inulin load” (in mg/min). So, we were interested to include such a test statement to see the response in the sample of students from 41 different medical schools from 14 countries.
The authors are aware of the recommendation to avoid words like “always” in item writing as testwise students are taught to recognize such construction as generally being false. Since we were dealing with a selected population of students representing their medical schools, a few of these “always” statements were intentionally formulated to test for a grasp of definite concepts in physiology. In another “always” sentence under the cardiovascular system, “Hypovolemia is ‘always’ compensated by a tachycardic response if the cardiac pacemaker function remains normal,” most of the 200 students did answer correctly as true, with only 21 students who gave the wrong false response.
There was no particular greater weakness or more misconceptions in any specific physiology system that could be logically summarized from the IMSPQ competition. In Table 2, we simply highlighted the major error-prone areas: 5 renal, 5 gastrointestinal, 4 respiratory, 2 cardiovascular, and 3 core topics on membrane potential, muscle, and tonicity. Since only a limited number of questions were asked for each system in this brief 75-min IMSPQ (which was not in the first place intended to be a study aimed to uncover misconceptions), it would be premature to make any conclusions regarding any predominant misconception-prone areas in physiology. Other studies, however, seem to indicate more difficulties among students tackling respiratory and cardiovascular physiology (5, 8, 10, 12).
Of the top eight scoring teams in the T/F MCQ test, three teams (Chulalongkorn University and Mahidol University from Thailand and Second Military Medical University from Shanghai, China) were from medical schools that do not use English as the medium of instruction. In actual fact, a considerable number of students at the IMSPQ gathering were from medical schools (Table 1) that do not use English as the primary medium of instruction.
There are important relationships between comprehension of scientific/physiological language and learning/understanding a concept (6, 11). A few examples from the list of conceptual statements answered incorrectly (Table 2) illustrate how language and other factors might cause the following misconceptions.
In the statement “The partial pressure of CO2 in alveolar air is greater than in expired air” (Table 2, true statement 5), a misconception arises here between the meaning of the same word conveyed by vernacular and technical scientific language (6). Students may associate the word “expired air” with obvious more CO2 metabolic respiratory waste. Here, the essential concept of anatomic dead space and its relationship to tidal volume should be highlighted during the teaching. We can similarly think here of the vernacular use of the word “elastic” meaning more stretchability, whereas for physiological structures, a more elastic blood vessel, like an artery, means the opposite property, a greater resistance to stretch or less compliance compared with a less-elastic, high-capacitance vein.
In the statement “In chronic diabetes mellitus with reduced [glomerular fitration rate], the renal plasma threshold for glucose is increased” (Table 2, true statement 6), students quite often mistook this “plasma threshold” with another “threshold” related to the maximum limit of proximal tubular reabsorption of glucose. One way to help students avoid this mix up is to tell them to take note of the different units for the “plasma threshold” (a concentration threshold, in mg/ml) and the “reabsorption threshold” (a rate threshold, in mg/min).
It is a little unfortunate that the word “load” in renal physiology is an accepted terminology when a process rate, rather than an absolute amount, is actually the meaning in the statement “The excreted load of a solute is calculated from multiplying the urine volume and the urine concentration of the solute” (Table 2, false statement 2). The lecturer can point out that the “load” (whether filtered or excreted) has the units of mass per minute and not merely mass alone. Once that is understood, the flow rate of either urine or glomerular filtrate (in vol/min) must be used in the determination of the “load.” Those of us who regularly teach renal clearance may similarly encounter the students who confuse the word “clearance” to mean how much “solute is cleared in urine” (mass/time) rather than the abstract concept of how much “virtual volume of plasma has been cleared of that solute” (volume/time).
A final example is seen in the statement “Intestinal epithelial cells secrete disaccharides into the lumen to digest maltose and lactose” (Table 2, false statement 8). The strict definition of “secretion” includes either from the cytosol into the lumen or transepithelial secretion from a capillary into the lumen. The disaccharidases are rather enterocyte membrane enzyme components, and hydrolysis to monosaccharides occurs on the cell surface. Specific definitions of major physiological process like “secretion,” “reabsorption,” and “excretion” must be emphasized to our students. We still hear students loosely speaking of “the kidneys secrete urine!” We should declare to our students that there is no need for the renal tubules of the kidneys to secrete urine, since the glomerular filtration rate is a tremendously large volume of 180 l/day.
The oral IMSPQ competition, held before a live audience, is always an adrenaline and excitatory postsynaptic potential-generating event. Quite consistent with the teams' performances in the written test, six of the top eight scoring teams competed at the semifinals of the oral quiz.
The IMSPQ questions provided unique insights into common areas where most medical students globally misconceive physiological mechanisms. Besides becoming an annual platform for networking among future medical professionals, the IMSPQ provides an invaluable setting to highlight common areas where the understanding of physiological processes perhaps needs more attention and focus.
No conflicts of interest, financial or otherwise, are declared by the author(s).
Author contributions: H.-M.C. conception and design of research; H.-M.C. performed experiments; H.-M.C. analyzed data; H.-M.C. and D.D. interpreted results of experiments; H.-M.C. and D.D. prepared figures; H.-M.C. and D.D. drafted manuscript; H.-M.C. and D.D. edited and revised manuscript; H.-M.C. and D.D. approved final version of manuscript.
- Copyright © 2012 the American Physiological Society