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tt1_2002a - Version A Name Student Number Questions needing...

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Unformatted text preview: Version A Name Student Number Questions needing attention DEPARTMENT OF PHYSIOLOGY UNIVERSITY OF TORONTO PSL 200Y / 201Y Tuesday, November 12, 2002, from 17:30 — 18:30 31 Questions (7 pages) DO NOT BEGIN WRITING UNTIL INSTRUCTED TO DO SO W l. 2. Bubble in your family name beginning in column 1 ofthe NANLE field. Bubble in your student number, beginning in column I of the Student Number field There are several versions of this question paper. Each contains the same questions, but their sequence varies. Question 1 identifies the Version that you have been given. THE CODING OF THIS QUESTION ON YOUR CONIPUTER CARD MUST BE DONE CORRECTLY AND APPEALS THAT A STUDENT MADE A. N ERROR WILL NOT BE ACCEPTED. All questions are of equal value. Spelling and/or typing errors do not make a statement incorrect. Invigilators are not permitted to interpret questions to individual students. Ifyou think a question is ambiguous, answer as you understand it, then explain your reasoning on your question book, n_ot on the Answer Card. You must also record the question number on the line “Questions needing attention" at the top ofthis page. Your computer card must be handed in at the end ofthe examination. —_' .‘- . - ~ .14; ‘ ‘~s. '5. O. q, ' -.-..,;__._ a“ 7‘. saw .fi, __.. .9-‘ .‘fl 1. Fill'i-inn A on .youffiriswer sheet I" n ‘17 New on the job, Robin decided to improve the intravenous drip solution by mixing 0.9% NaCl and 5% glucose solutions together. This new mixture, he. . reasoned, will be both iso-osmotic and ensure the extracellular ionic composxtlon sufficient to temporarily maintain the normal membrane potential of most cells. He decided to test this new concoction in a Petri dish containing a sample of mouse brain tissue. What will be the effect? (A. Brain cells will burst due to osmotic shock z Membrane potential will be maintained and glucose will be used to fuel the Na/K pump. C. Cells will shrink and die D. Membrane potential of brain cells will be slightly depolarized but the osmotic pressure will be maintained. 3. A new strain of genetically-engineered mice produces the chloride-dependent action potentials. Assuming that the extracellular concentration of Chloride (Cl') I”? is equal to 150 mM and intracellular concentration is equal to 5 mM, calculate the _,,.~\ =73 maximum possible amplitude of the action potential in this mouse using the f. c. \ Nemst equation. E=60*log(Cl;,,/Clom). Assume resting membrane potential of —70 \v/ mV. The value will approach: A. 100 mV . +40 mV —89 mV D. — l9mV 4. Which mechanism in the skeletal muscle will increase muscle fati c (reduce strength of muscle contraction)? ‘ ' "/7 A. Increased frequency of action potentials in the parasympathetic nervous system? ' ‘3. Increased excitation/contraction coupling? , - "ED/CK Reduced number of motor units innervating the muscle?-’.—- .SXB'Z Reduced activity of acetylcholinesterase? \ Botox is a new drug used to reduce muscle contraction for therapeutic or cosmetic (e.g. wrinkles) reasons. What is the most likely action ofthis drug on neuromuscular transmission? - X Blockade of acetylcholinesterase? B. Blockade of voltage-dependent sodium channels? . C. Blockade of muscarininc acetylcholine receptors? _ 7 D. Blockade of transmitter release at neuromuscular junction? K I/’ 7 . 6. “Warm up” before exercise includes activation of which system? A. Parasympathetic nervous system? / B. Sympathetic nervous system? C Cooperative activation of sympathetic and parasympathetic nervous systems? 74.,D. Antagonistic activation of sympathetic and parasympathetic nervous systems? “— 7. Muscarine is an irreversible agonist of the acetylcholine receptors in the heart. What effect will muscarine have on heart rate? A. Increase @ Decrease/ cardiac arrest - C. No change D. Same as acetylcholine 8. Smooth muscle is distinguished from striated muscles by: A. Lack of actin and myosin 7‘ ./ B. . Different sources of calcium ~‘ C. Speed ”of excitation D. Lack of innervation +1 ,3‘. Excitation/contraction coupling in the muscle: y A. Is equivalent to cross bridges formation A B. Involves release of calcium into' the cytoplasm"/07fz0-‘” /' C. Is a characteristic of striated but not smooth muscle *' '/'—> ' D. Is the process of muscle excitation by synapses 7 10. Which of the following statements is/are true? I. The Forced Expiratory Flow in one second is a more valid measurement of respiratory “fitness” than a Vital Capacity measurement II. A typical time for a breath in a resting breathing cycle is two seconds - III. The nose warms, filters and humidifies inspired air IV. When exercise is vigorous we switch from nose breathing to mouth breathing J-It ,I, ,III, IV, I III, IV, ) , II, III, II, III, IV mdflWf I—‘D—fl ’ ll. 12. 13. 14. 15. 16. A typical value for resting tidal volume is: A. 200 ml B. 800 ml C. 500 ml D. 1000 ml E. 650 ml A typical value for Vital Capacity is: A. 500 ml B. 5000 ml C. 10,000 ml D. 20, 000 ml E. 200 ml With an increase in C02 and thus hydrogen concentration, the oxygen dissociation curve will: A. Shifi to the right B. Become elliptical C. Shift to the left D. Straighten out When the oxygen dissociation curve shifts to the lefi ................ will be released fi'om hemoglobin: A. less oxygen B. no oxygen C. more oxygen D. Calcium ions The affinity of carbon monoxide for hemoglobin is about times that of oxygen: A. 300 ._ B. 700 c. 100 D. 1,000 The breath sound check is a field test that: A. Approximates the Ventilatory Threshold B. Approximates the Maximum Oxygen Uptake C. Corresponds to your blood pressure D. Indicates that Intensity of exercise is above the Anaerobic Threshold 17. Which of the following statements is/are true? I. Hypoxia increases the sensitivity of the peripheral chemoreceptors to C02 II. Hypoxia by itself is not a strong stimulus to breath TH» Hypercapnia (high C02) is a weak stimulus to breath IV. Hyperventilation increases the pressure of oxygen in the blood A. I, II, B I, III, C. I, 11, IV, R I, II, In 18. Exercising at the Ventilatory Threshold will: A. Increase the Ventilatory Threshld B. Increase the Anaerobic Threshold C. Increase Maximum Oxygen Uptake D. Increase all of the above 19. The talk test helps to ensure the exercise is: A. Anaerobic in nature B. Aerobic in nature C. Difficult to perform D. Only performed by mountain climbers 20. Which of the following statements is/are true? 1. The Talk Test and Breath Sound Check were developed at the University of Toronto 11? Hyperventilation before swimming under water is a good idea TIL When holding your breath the main drive to breath is due to. hypoxia IV. The alveolar volume is important in gas exchange K. 1, II, B/. 11,11, IV (2. I, III " D. I, IV E 111, IV 21. The P-wave of the electrocardiogram (ECG) occurs about the same time _>z‘A. as the opening of the aortic valve; ~‘ B. as the closing of the mitral valve; 7 C. as the contraction of the ventricles; ~ D. as the ventricles eject blood into the aorta and pulmonary arteries. 1/ E. as the contraction of the atria; ‘ 22. 23, .- .'/' 25. 26. 27. The Purkinje fibers \A. are the pacemaker cells of the heart; K are the contractile cells of the heart; _ 8.. make up the atrio~ventricular (a-v) node in the heart; S’D'.‘ connect the bundle branches to the ventricular myocytes; E connect the sino-atrial (s-a) node to the coronary sinus. During the ST segment of the electrocardiogram _A. the ventricular myocytes are depolarized; ‘-‘\.\ {V "B. the atrial myocytes are depolarized; " K the ventricular myocytes are repolarized; IV' D. the atrial myocytes begin to repolarize; K the atrio-ventricular (a—v) node begins to depolarize. If atrial and ventricular contraction occurred at the same time 3% the aortic valve would remain open during ventricular diastole; B. ventricular filling would be completely prevented; ' ‘Q ventricular filling would be slightly less; bx atn'al systole would be prevented; E. the mitral valve would be open all the time ° The mitral (bicuspid) valve i’ . is always closed when the tricuspid valve is open;,~ closure is associated with the second heart sound 3%“ is located between right atrium and ventricle; V is closed when the aortic valve is open; is open when the aortic valve is open ,4 Y‘- mébm> Ventricular ejection occurs 1>< A. during isovolumic systole; “313‘ during isovolumic diastole; u: R immediately after atrial contraction; D. after isovolumic systole; \B afler isovolumic diastole. The first heart sound: L/' A. signifies the start of ventricular systole? L/KBL.‘ occurs when the a-v valves close; ./ C. occurs when isovolumic contraction of the ventricle begins; 4 / D. is NOT the start ofventn'cular filling; @ all of the above are correct 28 . Which one of the following is NOT TRUE about the end-diastolic volume A. is the volume of blood contained in the ventricle just before ventricular systole starts; F- ® is the volume of blood contained in the ventricle when the second heart sound occurs; C. sets the degree of overlap of actin and myosin filaments;’ D. determines the stroke volume according the Frank-Starling relationship ’ E. is always larger than the end-systolic volume 29. Closing of thexaortic and pulmonary valves occurs XA. whenxa‘trial‘pressure rises above ventricular pressure; 9 B. when ventricular pressure falls below aortic pressure; © when right and left ventricular pressures fall below aortic and pulmonary arterial pressures; b. when aortic pressure falls below left atrial pressure; "‘13. when lefi and right atrial pressures rise above lefi and right ventricular pressures. 30. Which of the following statements describes best the Frank-Starling Law of the heart?: A. when more calcium is released inside the cardiac myocyte, the stroke volume ejected is increased; B when the sarcomere is shorter, the stroke volume is increased; when the end-diastolic volume is increased, the stroke volume ejected is increased; C. B. when the end-systolic volume is increased, the stroke volume ejected is increased; E. the hydrostatic pressure declines progressively along the capillary. 31. Select the most appropriate answer regarding the regulation of the heart rate X. can vary over about five-fold range in most individuals; R is slowed by the release of nor-adrenaline from sympathetic innervation of the s-a node; C. the release of noradrenaline slows the rate of spontaneous depolarization of the s-a node cells; D. all of the above are true; .33} none of the above are true ...
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