Biology 3U03 - Exam 1 Fall 2007

Student Name:Student #:BIOLOGY 3UO3DAY CLASSDURATION OF EXAMINATION: 2 hoursDr. C. M. WoodMcMaster University Final ExaminationDecember 2007THIS EXAMINATION PAPER INCLUDES 11 PAGES AND 43 QUESTIONS. YOU ARERESPONSBILE FOR ENSURING THAT YOUR COPY OF THE PAPER IS COMPLETE. BRING ANYDISCREPANCY TO THE ATTENTION OF YOUR INVIGILATOR.Special Instructions:Print your Name and Student # on page 1, 8, 9, 10 and 11 of this examination paper.This examination consists of three parts. Part I consists of thirty four (34) multiple choicequestions worth 1 mark each. These must be answered on the optical scan sheet provided.Part II has six(6) short explanatory notes worth 3 marks each. Part III consists of 3 shortessays worth 6 marks each. Part II and III must be answered in the space provided on thisexamination.Standard Casio-FX 991 calculator allowed.OMR EXAMINATION - INSTRUCTIONSNOTE:IT IS YOUR RESPONSIBILITY TO ENSURE THAT THE ANSWER SHEET ISPROPERLY COMPLETED. YOUR EXAMINATION RESULT DEPENDS UPONPROPER ATTENTION TO THESE INSTRUCTIONS.The scanner, which reads the sheets, senses the bubbled shaded areas by their non-reflection of light. Aheavy mark must be made; completely filling the circular bubble, with an HB pencil. Marks made with apen or felt-tip marker will NOT be sensed. Erasures must be thorough or the scanner may still sense a mark.Do NOT use correction fluid on the sheets. Do NOT put any unnecessary marks or writing on the sheet.1. On side 1 print your student number, course name, section number, instructor name and the date in thespaces provided. Then the sheet MUST be signed in the space marked SIGNATURE.2. Mark your student number in the space provided on the sheet on Side 1 and fill in the correspondingbubble number underneath.3. Answers, mark only ONE choice from the alternatives (1,2,3,4,5 or A,B,C,D,E) provided for eachquestion. If there is a True/False question, enter response of 1 (or A) as True, and 2 (or B) as False. Thequestion number is to the left of the bubbles. Make sure that the number of the question on thescansheet is the same as the question number on the test paper.4. Pay particular attention to the Marking Directions on the form.5. Begin answering questions using the first set of bubbles, marked "1".McMasterUniversityEXAMINATIONANSWER SHEET----adidascontinued on next page BIOLOGY 3UO3 (McMaster University Final Examination)Page 2 of 11Questions - 1-22 Multiple Choice: Choose the one fully correct answer no penalty for guessing1 mark each.1.The phase of the cardiac cycle where ventricular pressure falls slightly below aortic pressure, butoutflow continues briefly, is calleda. isobaric contraction phaseb. isovolumetric relaxation phaseC. isovolumetric ejection phased. isotonic relaxation phasee. none the above2.The autonomic nerves which cause relaxation (dilation) of the bronchi, intestine and uterus:a. are sympathetic, and act on 1 adrenergic receptorsb. are sympathetic, and act on 6 2 adrenergic receptorsC. are parasympathetic, and act on muscarinic cholinergic receptorsd. are sympathetic, and act on muscarinic cholinergic receptorse. are parasympathetic and act on a 1 adrenergic receptors3.Typically, the Pco2 gradient from pulmonary blood to alveolar air in mammals at rest isa. ~ 100 torrb. > 40 torrc. e 50 torrd. < 5 torre. ~ 70 torr4.In the indicator-dilution method for measuring cardiac output, a very high blood flow ratea. would be reflected in a large area under the dye-concentration versus time curveb. would be reflected in a small area under the dye-concentration versus time curvec. would result in a square profile in the dye-concentration versus time curved. would eliminate the recirculation part of the dye-concentration versus time curvee. would be reflected in a greater arterial-venous difference in dye concentration, from whichcardiac output could be directly calculated.5.In pathological conditions that cause chronic decreases in total peripheral resistance, there isa. no change in cardiac outputb. a chronically low cardiac outputc a chronically elevated cardiac outputd. a chronic decrease in blood flow to the lungse. none of the above are correct6.Changes in myocardial contractility usually reflecta. changes in the fuel supply to the Purkinje fibresb. changes in the amount of Ca2+ mobilized per action potential into the ventricular musclecellsc. changes in the intracellular pH of the sarcoplasmd. changes in degree of overlap of the thick and thin filaments in the sarcomeres at the start ofcontractione. changes in end diastolic volumecontinued on next page BIOLOGY 3UO3 (McMaster University Final Examination)Page 3 of 117.If a response is blocked by the drug atropine, it is probablya. normally stimulated by acetylcholine circulating in the blood plasmab. normally stimulated by sympathetic pre-ganglionic fibres acting at post-ganglionicmuscarinic receptorsc. normally stimulated by acetylcholine released by post-ganglionic fibresd. a response mediated through 2-adrenergic receptorse. normally also blocked by phentolamine and phenoxybenzamine8.A useful emergency treatment for someone suffering from chronic mountain sickness isa. making her breathe air which is enriched in CO2b. bleeding herc. making her hyperventilate by re-breathing into a bagd. making her breathe air which has a lower concentration of O2e. severely restricting her intake of fluid9.According to the classic analysis of Hurtado, the compensations which occur in humans livingat high altitude are primarily directed ata. maintaining tissue P02 (as indicated by Pvo2), as high as possibleb. maintaining a high Po2 gradient from the systemic arterial blood to the systemic venousbloodc. minimizing cardiac work loadd. reducing the O2 diffusing capacity of the lunge. exploiting the Bohr effect10.You are asked to calculate a Q10 Value for the temperature increase from 25°C to 38°C wherethe heart rate increased to 85 beats/min from the original 70 beats/min. What would be the Q10value?a. 0.9b. 0.74c. 2.1d. 1. 875e, 1. 1611. What is the effect of a period of conscious hypoventilation on the following involuntaryrespiratory rate and amplitude of breathing?a. respiratory rate and amplitude of breathing decreases due to a hypocapnic conditionb. respiratory rate and amplitude of breathing increases due to a hypercapnic conditionC. respiratory rate and amplitude of breathing increases due to a hypercapnic conditiond. there is no change after hyperventilation due to the increase of oxygen available in the lungse. respiratory rate and amplitude of breathing increases due to a hypocapnic condition12.Under normal circumstances, as blood plasma passes through the glomerular capillaries, thefiltration fraction isa. above 99%b. less than 1%c. between 40 and 60%d. 2-3%e. about 20%continued on next page BIOLOGY 3UO3 (McMaster University Final Examination)Page 4 of 1113.If end diastolic volume is 150 ml, end systolic volume is 50 ml, and heart rate is 60 per minute,then:a. the cardiac output is 6 L per minuteb. the ejection fraction is 33%c. the stroke volume is 50 mld. all of the above are correct.e. none of the above are correct14.A person has a severe influenza, and suffers a day long bout of both vomiting anddiarrhoca. What statement about his acid-base status is most reasonable.a. since both vomiting and diarrhoea cause the loss of HCO3 from the body, he is undoubtedlyin a state of metabolic alkalosis, with respiratory compensation.b. since both vomiting and diarrhoea cause the loss of HCO3 from the body, he isundoubtedly in a state of metabolic acidosis, with respiratory compensationc.since both vomiting and diarrhoea cause the loss of metabolic acid (H+) from the body, he isundoubtedly in a state of respiratory alkalosis.d. since vomiting causes the loss of loss of HCO3 from the body, anocauses the lossof metabolic acid (H*) from the body, it is difficult to make a firmabout his acid-base status.e. none of the above are reasonable statements.15.In Heyman's classic "cross-circulation" experiments:a. injection of adrenaline into the donor dog increased blood pressure in the systemiccirculation of the donor dog, but not in the systemic circulation of the recipient dog.b. cutting the neck nerves in the donor dog abolished the heart rate response to adrenalineinjection in the recipient dog.c. injection of adrenaline into the donor dog decreased heart rate in both donor and recipientdog.d. all of the above are correct.e. none of the above are correct.16.Which of the following is/are correct?a. the carotid body is an alternate name for the carotid sinus baroreceptorsb. the aortic bodies are innervated by a branch of glossopharyngeal nerve (IX) and detect thelevel of MAP.c. the carotid sinus baroreceptors cover a somewhat lower range of MAP than the aortic archbaroreceptors.d. all of the above are correcte. none of the above are correct.17.Which of the following would not happen after a severe haemorrhage?a. mobilization of ADH (antidiuretic hormone) into the circulation.b. increased secretion of adrenaline into the blood stream.C. an increased secretion of renin into the bloodstream, resulting soon in increasedconcentrations of angiotensin II in the bloodstreamd. increased activity of the parasympathetic nervous system.e. decreases in glomerular filtration rate and urine flow rate.continued on next page. BIOLOGY 3UO3 (McMaster University Final Examination)Page 5 of 1118.In the original heart-lung preparation of Starling which of the following statements is not true?a. the lungs remained ventilated and blood flow to the lungs continuedb. the two ventricles together were enclosed within a device which recorded changes in theirvolumec. the left ventricle pumped into an artificial resistanced. the venous return to and filling pressure of the right ventricle were experimentallymanipulatede. all of the above statements are true19.The venous return curves used by A.C. Guyton to describe the regulation of cardiac outputa. are plots of right atrial pressure (y-axis) against cardiac output (x-axis)b. are plots of venous return (y-axis) against right atrial pressure (x-axis)C. are plots of cardiac output (y-axis) against right atrial pressure (x-axis)d. are plots of cardiac output (y-axis) against TPR (x-axis)e. are plots of MAP (y-axis) against cardiac output (x-axis)20.The fastest active homeostatic response to a sharp change in blood pressure occursa. via the action of the arterial baroreceptorsb. via the compliance responses of the resistance vesselsc. via the Starling-Landis filtration mechanismd. via kidney filtratione. via the renin-angiotensin-aldosterone system21.The clearance ratio of inulin is:a. ~ 125 ml/minb. 0c. 1.0d. generally > 90%e. dependent on the state of water balance of the subject22.If the glomerular filtration rate of a substance is 10 umol/min, the urinary excretion rate is3umol/min, and the plasma concentration is 30 umol/ml, then its clearance rate is:a. 3 ml/minb. 0.1 ml/minc. 67%d. 33%e. impossible to calculate from the information given23.During the compensation of chronic metabolic acidosis by the kidney:a. net acid excretion by the kidney increasesb. amino acid metabolism in the kidney tubules is reorganized such that more glutamine issynthesized and oxidizedc. the major urinary buffer is ammonia, which carries out H in the urine as NH4+, therebyadding a new HCO3 to the bloodstreamd. all of the above are correcte. answers a and b are correct but c is falsecontinued on next page. BIOLOGY 3UO3 (McMaster University Final Examination)Page 6 of 1124.Which of the following statements about ADH is correct.a. ADH is released by giant neurons which run from the pre-optic nucleus of the hypothalamusto the anterior pituitaryb. the release of ADH is stimulated by ethanolc. while ADH acts on all segments of the nephron, its quantitatively greatest effects are on theproximal convoluted tubuled. all of the above statements are correcte. none of the above statements are correct.25.A patient is both water-depleted and salt-depleted. Which of the following treatments would helpher the most?a. ADH infusion and aldosterone blockadeb. ADH blockade and aldosterone infusionc. ADH infusion and aldosterone infusiond. ADH blockade and aldosterone blockadee. Atrial natruretic (factor) hormone infusion26.The kidney:a. produces no hormones (only enzymes) and therefore cannot be considered an endocrine glandb. filters a sample of virtually everything in blood plasma, reabsorbs what is valuable, andsecretes the remainder to form the primary urine.c. forms primary urine by glomerular filtration and then subsequently modifies its volume andcomposition by reabsorption and secretion processes.d. all of the above are correcte. none of the above are correct27. Pco2 gradients across the lungs (alveoli to pulmonary capillaries) are much lower than Po2gradients becausea. the CO2 molecule is 1/30th the size of the O2 molecule.b. CO2 is 30 X more soluble than O2 SO CO2 diffusion per torr of gradient is much greater also.c. only 1/30th as much CO2 is produced relative to the O2 consumed.d. O2 diffusion per torr of gradient is 30 X greater than CO2 diffusion per torr of gradient.e. the affinity of hemoglobin for CO2 is 30 X greater than the affinity of hemoglobin for O2.28. Glomus cellsa. are an important component of the peripheral arterial chemoreceptors.b. are innervated by branches of cranial nerves IX and X.c. may be evolutionarily derived from the neuroepithelial cells ("NEC's") on the efferentbranchial arteries of fish gills.d. all of the above are correct.e. none of the above are correct.29.The two major buffer systems in the blood area. the phosphate and ammonia systems.b. the phosphate and CO2/HCO31 systems.c. the protein and phosphate systemsd. the CO/ HCO3 and protein systems.e. the ammonia and CO2/HCO3 systems.continued on next page. BIOLOGY 3UO3 (McMaster University Final Examination)Page 7 of 1130.Which of the following substance is a naturally occurring GFR marker in humans.a. para amino hippuric acid.b. glutamine.c. insulin.d. creatinine.e. glucose.31. In the mechanism of glomerular filtration :a. constriction of the afferent arteriole will increase filtration rate.b. constriction of the efferent arteriole may either increase or decrease filtration rate dependingon the degree to which blood flow rate through the glomerulus is changed.c. the large amount of protein normally present in Bowman's capsule is a critical determinant offiltration rate.d. filtration rate normally falls as mean arterial blood pressure increases and vice versa.e. none of the above are correct.32. The cells in the late distal convoluted tubule and common collecting duct which are capable ofpowerful acidification of the urinea. are the principal cells.b. use a Na*/ exchange mechanism.c. actively secrete NH4 to achieve very low urine pH.d. contain no carbonic anhydrase.e. none of the above are correct.33. Which of the following terms correctly describes the net renal acid excretion rate by the kidneya. UFR X [Titratable Acidity + HCO - Ammonia]b. UFR X [ Titratable Acidity + Ammonia]HCO3c. UFR X [Titratable acidity + Ammonia- HCO3]d. UFR X [Ammonia - Titratable acidity] + HCO3e. UFR X Titratable acidity.34.The Magadi tilapia is unusual amongst teleost fish in:a. producing 100% urea-N as its N-wasteb. producing 100% uric acid-N as its N-wastec. living in an environment where the pH is normally 4.0d. tolerating a temperature range of almost 10°Ce. none of the above are correct,continued on next page Student Name:Student #:BIOLOGY 3UO3 (McMaster University Final Examination)Page 8 of 11Questions 35-40: Write short explanatory notes on the following ( 3-4 sentences suggested)3 marks each35. Cardiac compensation and its relationship to muscle ultrastructure36. Juxtaglomerular apparatus and its role in extracellular volume control37. The Henderson-Hasselbalch equation as a tool for understanding blood acid-base statuscontinued on next page. Student Name:Student #:BIOLOGY 3UO3 (McMaster University Final Examination)Page 9 of 1138. The central generation of breathing rhythm and amplitude39. Lung diffusing capacity, and the importance of CO in its clinical measurement.40. Anatomical deadspace and how it is measured.continued on next page Student Name:Student #:BIOLOGY 3UO3 (McMaster University Final Examination)Page 10 of 11Questions 41-43: Please answer in the space provided in essay format6 marks each.41. Write a short essay on the functions of the two parts of the adrenal gland and the hormones they produce,the mechanisms by which the two parts are controlled, and the functional relationships, if any, between thetwo parts42. Using three examples, write a short essay to illustrate how mechanisms or principles learned frommammalian physiology in this course are helpful in understanding the unusual physiology of the LakeMagadi tilapia.continued on next page. Student Name:Student #:BIOLOGY 3UO3 (McMaster University Final Examination)Page 11 of 1143. Explain the methods that can be used to measure (a) renal blood flow rate; (b) glomerular filtration rate;(c) urinary flow rate; (d) the urinary clearance rate of a particular substance (d) the urinary excretion rate of aparticular substance, and (e) the % net reabsorption of a particular substance by the kidney. For each describethe procedure in words and provide appropriate equations, defining all symbols used.THE END