Final Examination |
April 21, 1999. |
D. Stashuk |
Answer 25 of the 30 questions in the examination booklets provided. | No aids allowed | |
Measurement and Instrumentation Systems | 2 Questions (4 marks each Total 8): | |
1. Briefly, discuss some of the affects of two different technologies, which have been developed in the 20th century, on health care delivery. | ||
2. Briefly, discuss some of the major factors that need to be considered when obtaining measurements from a living system.
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Physiology of Excitable Cells and the Origin of Biopotentials | 4 Questions (4 marks each Total 16): | |
3. Briefly, describe the structure of the membrane of an excitable cell. Include the elements and aspects of the membrane that allow the cell to be excitable. | ||
4. Briefly, explain the creation of a Nernst potential. | ||
5. What aspects of an excitable cell determine its membrane potential? | ||
6. Briefly, explain why the amplitude of a current pulse, required to elicit an action potential in an excitable cell, decreases as it duration increases. Also, explain why there is a minimum amplitude for the current pulse, even if it is infinitely long. | ||
Biopotential Electrodes | 2 Questions (4 marks each Total 8): | |
7. Why are nonpolarizable electrodes so widely used? | ||
8. Briefly, describe the fundamental principles of operation of a carbon dioxide electrode. | ||
Skeletal Muscle System | 5 Questions (4 marks each Total 20): | |
9. Briefly, compare and contrast skeletal and cardiac muscle fibres. | ||
10. Briefly, describe muscle spindles and their role in peripheral muscle control. | ||
11. Briefly, describe the composition of a motor unit action potential. | ||
12. Briefly, discuss how characteristics of needle detected motor unit action potentials can be used to determine the state of health of a specific muscle. | ||
13. Briefly, describe how and why EMG signals can be detected and processed to measure muscle force. | ||
Central Nervous System | 5 Questions (4 marks each Total 20): | |
14. Briefly, describe the basil ganglia, its location and primary function. | ||
15. Briefly, what can be the affect of injury to the spinal cord and why? What determines the extent of the affect of a spinal cord injury? | ||
16. Briefly, compare and contrast EEG and EMG signals. | ||
17. Briefly, discuss how and why EEG signals can be used? | ||
18. How are auditory evoked potentials obtained? How can they be used? | ||
Cardiovascular System | 6 Questions (4 marks each Total 24): | |
19. Briefly, explain why the left ventricle of the heart is much bigger and stronger than the right ventricle. Briefly, explain the purpose and operation of the valves of the heart. | ||
20. Briefly, explain why SA node cardiac fibres have the shortest refractory period. What are some of the consequences of an improperly functioning AV node? | ||
21. Briefly, discuss one method for measuring cardiac output. Include some of the advantages and disadvantages of the technique discussed. | ||
22. Briefly, describe the major components of an ECG waveform and what cardiac activity they are related to. How can these components can be used clinically? | ||
23. What is considered competitive stimulation by a cardiac pacemaker? Why is competitive stimulation potentially unsafe and how can it be avoided? | ||
24. Why are cardiac pacemaker electrodes as small as possible, while cardiac defibrillator electrodes are as large as possible? | ||
Medical Imaging | 6 Questions (4 marks each Total 24): | |
25. What are two different methods of controlling the intensity of X-rays created by an X-ray tube? Which of these two methods is used to create diagnostic X-ray and why? | ||
26. Briefly, explain why contrasting substances such as barium sulphate are used to obtain X-ray images of the gastro-intestinal tract. | ||
27. Briefly, describe how X-ray CT scans are obtained and what determines their resolution. | ||
28. Briefly, explain the spin warp (phase encoding) method of obtaining MR images. | ||
29. Briefly, explain what factors determine the thickness of the tissue layer contributing to an MR image. | ||
30. Briefly, explain the sequence of excitation pulses required to use both the spin-lattice and spin-spin relaxation properties of a tissue to obtain contrast in an MR image. |