2007-08 Term Test 1 - T‘TI 2001/08 Form C J Name Student Number Questions needing attention DEPARTMENT OF PHYSIOLOGY UNIVERSITY OF TORONTO PSL

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Unformatted text preview: T‘TI 2001/08 Form C ' J Name Student Number Questions needing attention DEPARTMENT OF PHYSIOLOGY UNIVERSITY OF TORONTO PSL 200/201Y Term Test 1 Tuesday, October 30, 2007, from 16:45 — 17:45 34 Questions (10 pages) DO NOT BEGIN WRITING UNTIL [NSTRUCTED TO DO SO INSTRUCTIONS 1. 2. 3. Bubble in your last(family) name in tOp right box of the scantron. Bubble in your student number, beginning in the Student Number field. There are several versions of this question paper. Each contains the same questions, but their sequence varies. Do not forget to code for the answer sheet 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. If you think a question is ambiguous, answer as you understand it, then explain your reasoning on your question book, M on the Computer Card. You must also record the question number on the line, “Questions needing attention” at the top of this page. Your computer card and the test book must be handed in at the end of the examination. Fill in C in the Form box on the scantron Physio-Ex segment 1. A hypotonic solution is defined as: solution that has a lower solute concentration relative to another solution B) a solution that has a higher solute concentration relative to another solution m solution that has the same solute concentration relative to another solution D) a solution with a high concentration of NaCl 2. To study active transport, a membrane containing sodium—potassium ATPases is placed vertically in a beaker that contains water and lmM ATP. You place 20mM NaCl on the right side of the membrane and 40mM on the left side of the membrane. Will Na move across the membrane? A) Yes, to the right. B) Yes, to the left. C No, because ATP is not sufficient. ) 0, because there is no K. 3. You are an electrophysiologist studying the mechanisms of voltage—dependent sodium channels. You have 3 chemicals at your disposal in your lab: ether, lidocaine and curare. Which of these chemicals would be most beneficial to your research? ;A) lidocaine B) ether ‘ C) curare D) all of the above 4. A colleague of yours is studying the conduction velocities within nerves. She has 3 nerves: a small unmyelinated, a medium unmyelinated and a smalmyelinatgc‘l nerve. What nerve do you predict will have the fastest conduction velocity? Why? A) the small unmyelinated nerve. The small diameter allows for quick movement of the ions t ough the plasma membrane, allowing for a faster depolarization wave. e small myelinated nerve. The myelin sheath insulates the nerve, allowing for rapid, nodal ransmission of the depolarization. C) the medium unmyelinated nerve. The larger diameter allows for increased diffusion of ions from one end of the nerve to the other, increasing conduction velocity. ,Dj’both the unmyelinated nerves. The myelin sheath prevents movement of ions into the neurons, therefore impeding action potential conduction. 5. In skeletal muscle physiology, muscle fiber will contract if a stimulus is applied at or above the threshold voltage ’a in muscle twitch is defined as an action potential generated in a muscle fiber C) orepinephrine is released by the motor neuron ‘ D) oth A) and B) I 6. When stretched to near maximum (over 90 mm), why is there is a decrease in the force generated by the muscle? Qj‘m 90 mm there is no longer any overlap between the contractile mechanisms within the cell, Q only passive force is present. we /\ 13) At 90 mm the passive force decreases because the aitin filaments are being stretched. / t 90 mm the active force decreases because the load has lessened. ' ‘ At 90 mm there is a reduction in passive force due to a increase in muscle elasticity. w 7. In an experiment, the Wof the voltage, which ireshold, applied to skeletal muscle is Whis will result in: f.» A) an increase in the force generated by the muscle B) tetanus, if the frequency of the stimulus is sufficiently elevated fatigue, if the frequency of the stimulus is elevated and prolonged All of the above 8. In pneumothorax affecting the right lung, tmospheric pressure is the same as intrathoracic pressure in the right lung atmospheric pressure is lower than intrathoracic pressure in both lungs total flow is not affected in the right lung atmospheric pressure is higher than intrathoracic pressure in the right lung ) 9. Your friend has had a big scare and is now hyperventilating. Without help he may pass out. You decide to get him to breathe into a paper bag. Why does this help normalize his breathing? Rebreathing normalizes the PC02 of his blood, allowing for a return of normal signalling to s brainstem and in turn a normalization of his breathing. “'C) Rebreathing decreases the P02 in his blood. Chemoreceptors sense the decrease in 02 and normalize his breathing. M Breathing into a paper bag increases the amount of carbon monoxide in his blood. This triggers a response in the brainstem that normalizes his breathing. ' g: It doesn't help. In fact, you may be making it worse. 10. Asthma is an obstructive pulmonary disease and pulmonary fibrosis is a restrictive pulmonary disease. When it comes to respiratory volumes how are these two diseases characterized on a spirogram? A) Asthma shows a decreased FVC, but pulmonary fibrosis has a normal FVC. B) There is no change in the spirographs between these two diseases. Pulmonary fibrosis is characterized by a gradual increase in ERV and RV. oth asthma and pulmonary fibrosis have decreased TV and FVC, but pulmonary fibrosis also shows a diminished TLC, IRV and ERV. -"“‘ Dr. Woitowicz’ Lectures 11. During strenuous exercise a person can loose excessive amount of water by sweating and evaporation. This condition can lead to: A) Heat exhaustion B) Heat stroke ) Re—setting of the heat-sensing mechanism in the brain comparable to effect of pyrogens @Tr‘iggen’ng of the “exercise training” spiral that can lead to stress 12. Which of the following statements about homeostasis is FALSE? A) The body fluids are maintained in a state compatible with life I M he primary mechanism to maintain homeostasis is negative feedback hermoregulation is an example of a homeostatic mechanism fiyperthennia is a typical example of a “positive feedback” 13. “W’ is a pathological condition related to swelling of brain cells. This condition is most likely to be related to: A) Loss of body fluids due to sweating w B) Diffusion of ions from extracellular to intracellular medium C Lowering of concentration of water inside cells compared to the extracellular fluid Osmotic pressure developed by diffusion of water from outside to inside of cells 14. The reason(s) for all living cells having negative electrical charge is: Mccumulation of negatively charged ions and molecules inside cells ’BTDiffusion of potassium ions from regions of high concentration to regions of low concentration ‘ C) Activity of Na/K pump Relatively lower concentration of positively charged ions and molecules inside cells ) B and C (\ r 15. The essential difference between the resting membrane potential and the action potential is: A) Both potentials occur only in nerve and muscle cells yells with the resting membrane potentials are negatively charged and those with action potentials are positively charged _C)/Resting membrane potential depends entirely on potassium ions and the action potential on dium ions ATP is necessary for action potentials but not for resting potentials E) None of the above is correct 16. Using this modified Nemst equation, calculate membrane potential choosing the most reasonable ratio of Sodium: Potassium permeability (PM: PK) among the values listed here: (1:1), +104), (1:20) or 61-24-90) - ““ HS 5 2° 18 o Em: 60 X Log [(PNa (Na)o +PK (K)o )/( PNa (Nah: + PK (K)in)] Assume extracellular sodium concentration N a0: 145 mM, intracellular sodium concentration Nain = 20 mM, extracellular potassium concentration K0 2 5 mM, and intracellular potassium concentration Kin = 150 mM. The answer is: @331er H a” but ya B)—66.5 mV V2640“; £482 mV t:\oO /D)437 mV 17. Which mechanism in muscle contraction does utilize both Calcium ions and ATP? , _ , . (Twas bi =74th circle, with rattan rm to bean)» A) Sliding filament mechanism was M 9km mg W i} AWE)” ross bridges cycle xcitation/contraction coupling D) Calmodulin system in smooth muscle B) All of the above 18. Choose the correct sequence in muscle contraction 1— sliding of filaments, 2— excitation/contraction coupling, 3- synaptic transmission, 4—cross- bridges cycle ‘ A) 1—3—2—4, B) 2-4—3—1 C 2—3—4-1 @3244 E) 3-2—1-4 19. Which of the following best describes the function of transverse tubules (T) and sarcoplasmic reticulum (SR) in skeletal muscle contraction? A) Action potentials in T tubules trigger the release of acetylcholine which binds to receptors and the SR and triggers calcium release B) Action potentials in T tubules trigger the release of norepinephrine which binds the receptors \ on the SR and triggers calcium release © Action potentials in T tubules are detected by dihydropyridine(DHP) receptors which are coupled to ryanodine receptors in the SR and open calcium channels D) Action potentials in T tubules are detected by ryanodine receptors which are coupled to DHP receptors in the SR and activate calcium pump E) None of the above AGFWA mf‘ (“think a4 7 Mia WWU iv T misuth +1) mm {Week 20. Stress response is associated with reduced smooth muscle activity in the digestive system (the gut) and iWflXin the arterial walls. Assuming that sympathetic or parasympathetic is involved, which other responses should be present? a @creased release of norepinephrine from the adrenal gland ' /‘B)’li1creased release of acetylcholine from the parasympathetic ganglia JD/Reduced heart contractions due to reduced blood pressure M D) Reduced brain activity due to reduced blood pressure 21. Autonomic “righting reflex” controls blood pressure when a person stands up A) It is a response of a sympathetic nervous system B) It is a response of a parasympathetic nervous system C It is a response initiated by muscle contraction in the legs @It is a response initiated by reduced blood pressure in arteries and involves both sympathetic and parasympathetic nervous systems Dr. Goode’ Lectures 22. Which of the following best represents the ventilation at rest? A) Tidal Volume 2 1000 ml, Frequency = 30 breaths per min (b/min) B) Tidal Volume 2 5000 m1, Frequency 2 40 b/min ) Tidal Volume 2 150 ml, Frequency 2 20 b/min Tidal Volume = 500 m1, Frequency = 20 b/min 23. When one makes a maximal expiration, the air remaining in the lungs is called A) Expiratory Reserve Volume B Alveolar Volume esidual Volume D) Minute Ventilation \21 A baby holding its breath will: A \ automatically start to breathe again when the carbon dioxide levels in the blood reach a high \ enough value (D) have brain cells damaged because of low blood oxygen levels C) suffer heart damage because of increased pressure in the aorta D)Mbe termed a “blue baby” \N— we a . . . . . . . . \{l xi. 25. Moderate exercrse 1s sufficlently 1ntensrve to improve V02 max ( the maxrmum amount of fly oxygen that the mitochondria can consume, p. 78) when @e subject begins to hear their breathing and maintains this sound throughout his/her exercise 0 d. B) the subject has considerable difficulty talking during his/her exercise period. C) one stops producing hydrogen ion as a consequence of metabolism. D) the subject is speechless while performing exercise. 26. The “Talk Test,” created at the University of Toronto, places a “lid” on the exercise intensity. When one can carry on a conversation while exercising A the exercise is sufficiently intense to increase V02max. E3 he exercise is aerobic and the Kreb’s Cycle has sufficient oxygen to ensure its operation. C) the exercise is anaerobic and the breakdown of glucose to lactic acid increases. D) the metabolic cost of talking will quickly cause the participant to stop his/her activity. 27. Which of the following statements is/are most correct? When performing mouth to mouth resuscitation the rescuer must i) hyperventilate before blowing into the victim. ii) breath-hold before blowing into the victim. blow sufficient air to clear the dead space. iv) increase the inspired—alveolar difference. @blow sufficient air to see the chest rise. A)i, B) ii, iii, C) iii,iv, iii, v, E) i, v. 28. After hyperventilation for several seconds, a person experiences a short period of apnea (stopped breathing) because: Me level of oxygen has increased and inhibits the inspiratory centre B) the oxygen in the lungs has not had time to diffuse into the blood 6 pH would drop and inhibit inspiration D) the level of carbon dioxide would drop below the level necessary to stimulate the inspiratory center 29. Carbonic Anhydrase speeds up the reaction of C02 plus H20 in the red blood cell some A) 100 times B 1000 times C 10,000 times D) has no effect on this reaction, but plays a role in the Kreb’s Cycle. 00 30. The Alve\olar Air, Venous Blood difference in pressure for oxygen is 413147—100 = 47 mmHg/torr K v e" _B)'100—46 = 54mmHg/t01r ‘ 00—1 = 99mmHg/torr WK mo- 00—40 = 60 mmHg/torr \ 31. Most of the C02 produced in the mitochondiia is carried @in the form of dissolved C02 in the plasma. B) in the dead space volume of the lungs KC) in the form of bicarbonate and transported in the plasma. D) in combination with KOH to effectively reduce the content to zero. 32. Blood oxygen levels: A) are more important than carbon dioxide levels in the regulation of respiration B need to change only slightly to cause a change in respiration rate C “within the normal range of P02 levels have little effect on regulation of respiration in venous blood and arterial blood are about the same 10 33. PC02 is the highest in: (ONE CORRECT) '/ . . ., ~ . A) I l. a AgS‘w/Wmfi F001 m ht;st («flaw cw Rd"; 3 veo 1 . <’ B)‘ivenous blood M Vm'ijmckmfiwa ’ C) arterial blood ' @issue 34. Which of the following is the most powerful stimulus to breathe? @ WE w . Hypercapma and Hypox1a (low 02) ; B) Hypocapnia (low C02) and hypoxia C) Hypercapnia and Hyperoxia (high 02) D) Hypocapnia 10 ...
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This note was uploaded on 04/04/2011 for the course PSL 201 taught by Professor Wojtowicz during the Winter '08 term at University of Toronto- Toronto.

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2007-08 Term Test 1 - T‘TI 2001/08 Form C J Name Student Number Questions needing attention DEPARTMENT OF PHYSIOLOGY UNIVERSITY OF TORONTO PSL

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