This semester, we will be analyzing “cases in human anatomy and physiology.” Most simply, cases are stories-real or simulated-that illustrate important features of a field of study. In this course, we will analyze a selection of cases that illuminate important concepts of human anatomy and physiology. A case study may involve a case history (the description of the symptoms and the progression of a medical disorder), but it doesn’t have to. What is essential is that we address a real-world concern, i.e., a question, situation, or problem, by using the knowledge that we have gained about human anatomy and physiology.
Issues to Keep in Mind in Approaching Cases
In approaching the cases, you must keep the following issues in mind. What specific types of cells, tissues, organs, or organ systems are involved? What is the normal anatomy?
How do these structures work normally? What is the normal physiology?
What question must be answered? What problem must be solved? What specific situation must be addressed? What anatomical structures may be working abnormally? What are the physiological problems?
On the basis of your interpretation of the situation or problem, what medical or biological solution(s) could be proposed?
Suggestions for Successfully Answering the Case Study Questions
To answer the case study questions correctly, you must read them carefully and consider exactly what is asked for. The importance of your knowing exactly what a question is asking cannot be overstressed. Ask an instructor if you’re unsure.
DON’T necessarily think that simply copying a long section of relevant information from the text provides a suitable answer. You must ANSWER the QUESTION, NOT merely find facts.
If you QUOTE or PARAPHRASE the textbook you must give a page reference. Similarly, you must make proper reference to the lecture notes.
Imaginative speculation. Imaginitive speculation, where appropriate, is encouraged (and will be rewarded), i.e., “It is possible that a drop in plasma levels of calcium under these conditions would make the hormone imbalance worse since.. . ”
Brevity. Brevity will be rewarded. An answer in two sentences that can be provided in one should be. As Winnie-the-Pooh states, “I am a bear of very little brain and long words bother me.”
When a question asks: “Name... ” This requires the name of something.
“Name the top layer of the epidermis”
Answer: Stratum corneum.
“List... ” This requires a list of ALL of the items requested.
“List the major types of blood vessels.”
Answer: Arteries, arterioles, capillaries, venules, veins.
“Explain... ” This requires YOU to provide an explanation in YOUR OWN WORDS (not merely copying the text) of what is being asked?
‘ ‘Explain the difference between an ion channel and a pump. ’ ’
Answer: An ion channel is a membrane protein that permits ions to passively move across the cell membrane from regions of high concentration to regions of low concentration. A pump is a membrane protein that actively transports substances across the cell membrane from regions of low concentration to high concentration.
“What is...” This requires you to identify (or give a measurement of) the ITEM.
“What is the normal function of the heart?”
Answer: To pump blood.
“What is the approximate volume of blood in circulation? ’ ’
Answer: 5 liters.
“What is the role of voltage-gated potassium channels in producing the action potential?”
Answer: The opening of the voltage-gated potassium channels causes the repolarization and hyperpolarization of the membrane potential at the end ot the action potential.
"How..." This requires you to describe a process, a mechanism, or a series of cause-and-effect events whereby somethings occurs.
"How does ATP use by skeletal muscles lead to contraction?"
Answer: ATP binds to the myosin cross bridge formed between the thick and thin filaments and causes the myosin head to be released from its active binding site on actin. The hydrolysis of ATP then causes the myosin head to be reoriented and reactivated (reenergized) in preparation for its reattachment to another actin molecule, swiveling of the myosin head, and the exertion of the force of contraction.
‘ ‘Propose.. . ’ ’ This requires you to present a logical coherent series of steps/actions that would SOLVE the problem as presented.
“Propose a way to treat cancer that relies upon what you know about the causeso f uncontrolled growth of cells.”
Answer: Because uncontrolled growth in many cancer cells is associated with abnormalities in protooncogenes and tumor suppressor genes, it would be reasonable to intervene in the activities of these genes or the proteins that are made from them. For cancers arising from defects in protooncogenes, it would be useful to pharmacologically inhibit the actions of the growth-promoting oncogenes once they are produced or to enhance the counterbalancing actions of existing tumor-suppressor genes. Conversely, for cancers arising from a loss of tumor-suppressor gene activity, it would be useful to also suppress the actions of protooncogenes or to restore the normal actions of the tumor suppressor genes by gene therapy or by giving pharmacological agents that mimic the actions of the tumor suppressor proteins that have been lost.