Directed case approach to teaching human anatomy and physiology. Four distinguishing features characterized our directed case approach as follows: 1) defined, inclusive learning objectives; 2) an informative, engaging case scenario; 3) pertinent, didactic questions; and 4) information needed to answer the case questions is readily available to students.
We found a well-prepared series of learning objectives to be invaluable in the construction of an instructive case. Typically, we began with a list of anatomical and physiological principles that are to be illustrated by the case (i.e., “three phases of the control of gastric secretion”). Then we defined the particular aspects of each principle that were to be emphasized (“the interaction between neural and hormonal mechanisms in the control of each phase of secretion”).
Finally, we considered what idea or fact the student should know after completing the case analysis (“understand the relations between the neural and hormonal control of gastric secretion”). In our experience, the best case objectives should not be so narrow as to exclude key principles or essential concepts. On the other hand, the objectives should not be so broad as to make the case too diffuse or unrealistic. The case scenario could be a clinical case history or a situation of medical importance, but this is not required. It could be a scientific or real-world concern related to human anatomy and physiology. For example, to reinforce skeletal anatomy, one could construct a puzzle about the peculiar shapes of human bones found at an ancient burial site. In our experience, the best scenarios were short (5- 10 sentences at most), informative, and clearly written, giving all relevant information without unnecessary or obscuring detail. They were not too complex, difficult, or involved. Nor were they too simple, easy, or brief. They were interesting- sparking a reader’s curiosity. They could be entertaining-but not to the detriment of their instructional value. Throughout the development of the scenario, careful consideration was given to the relevant principles of anatomy and physiology that are to be emphasized and how the scenario illustrated them. We also constructed the questions with the underlying principles of anatomy and physiology in mind. The questions needed to be relevant; they must direct the reader to apply his/her anatomical and physiological knowledge to the case at hand. The questions needed to be instructive; their intent is to force the reader to gain a greater understanding of human anatomy and physiology (What specific types of cells, tissues, organs, or organ systems are involved, i.e., what is the normal anatomy. 3 How do these structures work normally, i.e., what is the normal physiology?). Because we wanted to place emphasis on the basic sciences, we decided that most of the questions should not have a clinical focus (i.e., What is the disease? What is its prognosis? What is the treatment?). We believe that students should be able to successfully answer the case questions with information that can be obtained in the lectures, the course textbook, and supplements. This approach focuses student attention on the lectures and the textbook and discourages inefficient searches through advanced source materials. Occasionally, we directed our students to specialized readings but only if it enhanced their understanding of the subject. For some cases, it was not unreasonable to expect students to create answers to all of the questions from information found solely in the textbook. In doing so, case work enabled students to learn a wider scope of material than could be presented in the lecture.
We wrote case studies for each of the major systems (i.e., muscular, nervous, cardiovascular) covered in a typical two-semester integrated anatomy and physiology course. All of the cases drew upon concurrent knowledge of the anatomy and physiology of each major body system. Tables of data or figures for drawing graphs were provided. Diagrams were given for exercises involving labeling or identifying anatomical structures. Research literature or short generalinterest articles were made available on reserve in the library. A detailed handout giving suggestions for successfully answering the case study questions was given out at the beginning of the semester (see APPENDIX I).
We found that a short focused scenario combined with lo- 15 directed questions provided suflicient depth of analysis without requiring excessive time or effort by the students. Because students would typically complete six to eight case analyses per semester, a requirement for short and concise cases was appreciated by students and instructors alike.
Representative case in human anatomy andpbysiol- O~JJ. A representative case in human anatomy and physiology is given in APPENDIX II. This case concerns the immune system and its role in the allergic response. Notice that the first five learning objectives are limited to the physiology of an allergic response. Nevertheless, embedded with these objectives is the implicit understanding of other important immunological concepts (i.e., the role of macrophages, B cells, and antibodies; the process of antigen sensitization; and the physiology of inflammation). Furthermore, orijectz’ues 6 and 7 are distinctly integrative goals in which the student must consider how alterations in immune cell function can lead to changes in the cardiovascular system, the respiratory system, and body fluid balance. Thus, although the case was limited to the allergic response, it covered a broader spectrum of topics in immunology and cardiovascular, respiratory, and body fluid physiology.
The case is concise. The clinical symptoms of the allergic reaction are summarized without embellishment. The events leading up to the main character’s allergic reaction are outlined succinctly. The events are realistic even though the plot itself is fictitious. Many students have heard of similar real-life occurrences. The man’s situation is painfully humorous.
The realism and the humor are designed to catch the student’s attention and maintain his or her interest. The specific cause or explanation for the man’s condition is not given, and none of the facts are obscured. The student must decide which of the man’s actions led to his predicament and analyze the reasons why.
The questions require a balance of fact recall, logical explanation, and synthetic analysis. From the information provided in the scenario and available in the textbook, the student is expected to diagnosis the man’s pathological state. The students are asked to review the cellular steps involved in antigen sensitization and arrange them in proper sequence. The students must identify the salient features of inflammation and attribute them to the actions of specific cells and tissues. The student is expected to understand the physiological rationale for the treatment given. In all of these activities, a student develops a synthetic or analytic outlook to the problem instead of merely reinforcing his or her talent for fact recall. Nevertheless, most questions do indeed direct the student’s attention to the facts and concepts of normal anatomy and physiology. This represents an opportunity for the student to review, reinforce, and gain a greater comprehension of the subject (i.e., the function of the immune system) instead of learning new information that may be tangential to the course (i.e., the treatment of allergic reactions). Moreover, some questions are integrative, requiring the student to associate the actions of one body system (i.e., release of inflammatory mediators by immune cells) with the responses of other systems (i.e., the effects on vasodilation and capillary permeability and the state of the cardiovascular system).
That nearly all of the answers to the case have citations to the text or supplements illustrates that the student can find facts, draw conclusions, or make inferences from information given in the text, lecture notes, or supplemental readings. Sometimes, this requirement might limit the scope of the case or restrict its logical development. However, given the wealth of information in modern texts in anatomy and physiology, we did not find that this restriction hampered our ability to construct informative cases or to use them effectively.
Use of directed case analysis in a course in human anatomy and physiology. We used the following procedure to integrate a regular program of case analyses into our two-semester anatomy and physiology course.
1) The students received a case study at the beginning of each of the lecture series on each major system of the body. Students handed in their answers during the class period immediately after the last lecture in the series. The answers to the case study were reviewed at this time. In a typical two-semester sequence, this meant that the students had the case studies for at least a week before they were due. This schedule was designed so that students could anticipate gaining insight about the case as they learned about the body system in the lecture or from reading the textbook.
2) The students completed the case analysis outside of class. They were free to work together in groups. Many used their lab partners as co-workers on the cases. Students were told that information provided in class or found in the textbook should be sufficient to answer the questions. However, they were free to use any sources of information.
3) The students were required to turn in their written answers on or before the day of the case study review. Severe penalties were fully discussed in class on the day that they were due.
4) After the written answers were handed in, each question was reviewed in sequence by having individual students read their answers to the class. The instructor initiated a give-and-take class discussion about each answer, during which time the instructor had the opportunity to make additional comments about the case, and the students could raise specific concerns about the questions and/or answers. In such a fashion, the case study was completely reviewed in class. Sometimes, a formal quiz was administered at the beginning of class to assess the student’s individual understanding of the material.
5) The written answers were graded and returned to the students. An answer key was posted in the student laboratory.
Providing a case study for each of the major body systems covered in the course made the cases a practical study aid and promoted immediate reinforcement of the lecture material as it was presented in class. Our students also used their corrected case analyses in preparation for their exams.
Students were encouraged to work on the cases in groups, and no penalties were imposed for case answers jointly submitted by the students who worked together. In this way, the case approach was a useful extension of the group learning methods that we have used in the laboratory portion of the course. Individual comprehension of the subjects covered in the case studiesw as assessedb y the scores on case-related questions on quizzes and/or exams.
We had no reservations about scheduling an entire class period to review each case (6-S class periods/ semester). In nearly every instance, we used the full 50 min of class time to discuss the correct answers; clarify misunderstandings about the case scenario, questions, and answers; and review the related ideas and principles of anatomy and physiology. This time provided us with a valuable opportunity to reinforce and reemphasize subject material presented previously in the lecture. Furthermore, these review sessions also gave us a chance to improve our assessment of student learning.