biology 2a03 quiz2 2011a

Biology 2A03 Quiz #2 March 7, 2011 Version 1 page 1/8

Biology 2A03 Integrative Physiology of Animals Quiz # 2, March 7, 2011 G.B. McClelland Specific Instructions: This test has 35 multiple choice questions on 8 pages. The questions start on page 2. Answer all of the following 35 questions on the optical scan sheet provided. There is only one fully correct answer for each question. This test is worth 10% of your final grade.

NOTE: IT IS YOUR RESPONSIBILITY TO ENSURE THAT THE ANSWER SHEET IS PROPERLY

COMPLETED: YOUR EXAMINATION RESULT DEPENDS UPON PROPER ATTENTION TO THESE INSTRUCTIONS.

The scanner, which reads the sheets, senses the shaded areas by their non-reflection of light. A heavy mark must be made, completely filling the circular bubble, with an HB pencil. Marks made with a pen 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. Sides 1 (red side) of the form, in the top box, in pen, print your student number, name, course

name, section number, instructor name and the date in the spaces provided. Then you MUST write your signature in the space marked SIGNATURE.

*2. IN THE SECOND BOX, WITH A PENCIL, MARK YOUR STUDENT NUMBER, EXAM VERSION NUMBER AND COURSE SECTION NUMBER IN THE SPACE PROVIDED AND FILL IN THE CORRESPONDING BUBBLES UNDERNEATH.

3. Use Red side of the form for questions 1-50 and grey side of the form for questions 51-100. Answers, mark only ONE choice from the alternatives (1, 2, 3, 4, 5 or A, B, C, D, E) provided for each question. If there is a True/False questions, enter response of 1 (or A) as True, and 2 (or B) as False. The question number is to the left of the bubbles. Make sure that the number of the question on the scan sheet is the same as the question number on the exam paper.

4. Pay particular attention to the Marking Directions on the form. 5. Begin answering questions using the first set of bubbles, marked 1.

Test starts on the next page


1. If an enzyme increases the affinity for its substrate:

A) at any given [S] more Enzyme Substrate (ES) complexes will be formed B) at any given [S] fewer ES complexes will be formed C) the same number of ES complexes will be formed at a lower [S] D) the Vmax for the reaction will decrease E) both A and C

2. In the do-it-yourself heart lab, removal of the balloon was performed to illustrate

A) The influence of increased arterial resistance as occurs during exercise. B) The influence of removing one of the two resistances in parallel. C) a stroke D) The influence of decreased venous compliance as occurs during hardening of the

arteries. E) None of the above are correct

3. Which statement best describes reactive hyperemia:

A) A decrease in bloodflow causes local chemical changes which triggers vasodilation and an increase in bloodflow

B) An increase in tissue metabolism causes local chemical changes which trigger vasodilation and increases bloodflow

C) A decrease in bloodflow to a tissue causes local chemical changes which trigger vasodilation and an decrease in bloodflow

D) A loss of blood supply to a tissue causes local chemical changes which trigger vasoconstriction and an increase in bloodflow

E) None of the above

4. Which of the following statements is true regarding norepinephrines effect on heart rate: A) It exerts its effect by binding to a beta-1 receptor on the pacemaker cell

membrane B) It is released by the vagus nerve of the parasympathetic nervous system C) It alters Na+ and Ca+ movements resulting in faster depolarization D) It alters Na+ and Ca+ movements resulting in slower depolarization E) Both A and C are correct

5. Which of the following is the correct conduction pathway through the heart?

A) Purkinje fibers ; bundle of His ; bundle branches ; SA node ; AV node B) SA node ; AV node ; bundle of His ; bundle branches ; Purkinje fibers C) SA node ; Purkinje fibers ; AV node ; bundle of His ; bundle branches D) AV node ; SA node ; bundle branches ; bundle of His ; Purkinje fibers E) Bundle of His ; bundle branches ; Purkinje fibers ; SA node ; AV node

Test continues on the next page


6. Which of the following is/are FALSE concerning an increased in stroke volume during

contraction of the heart: A) It can be due to an increase in end diastolic volume according to Starlings Law B) It can occur due to a decrease in end systolic volume C) It can result from an increased water reabsorption by the kidneys D) It can occur due to a vasodilation of the veins E) It can occur to compensate for a decrease in mean arterial pressure

7. The normal healthy heart never goes into decompensation because:

A) there is always enough epinephrine in the blood stream to maintain cardiac contractility

B) the pericardium prevents the end diastolic volume from becoming too large C) this is automatically prevented by the Frank-Starling relationship (Starlings

Law) D) end diastolic volume is always a constant fraction of end systolic volume E) the Purkinje fibres have a refractory period which limits the maximum heart rate

to ~ 240 beats per minute

8. During mild exercise, which of the following does NOT occur? A) There is a minor increase in mean arterial pressure B) Total peripheral resistance increases due to the predominant vasoconstriction of system arterioles C) Heart rate increases significantly more than stroke volume D) Pulse pressure increased mainly due to an increase in stroke volume E) Vasodilation in muscles leads to an overall decrease in total peripheral resistance

9. Which statement(s) are TRUE regarding the baroreceptors?

A) The are the most important long term regulator of mean arterial pressure B) They inform the central nervous system of mean arterial pressure through action potential size via afferent neurons C) They are located in the carotid sinus and aortic arch D) They trigger the somatic nervous system to vasodilate arterioles E) Both A and C

10. Which of the following is NOT one of the functions of the kidneys? A) Secretion of the hormone erythropoietin B) Secretion of the enzyme angiotensin converting enzyme (ACE) C) Gluconeogensis during fasting D) Secretion of the enzyme renin E) Regulation of plasma volume



11. Which muscle(s) that regulates micturition is under involuntary control? A) detrusor B) internal urethral sphincter C) external urethral sphincter D) detrusor and the internal urethral sphincter E) detrusor and the external urethral sphincter

12. The three major exchange processes occurring in formation of urine:

A) filtration, reabsorption and secretion B) filtration, reabsorption, and micturition C) filtration, abstraction and secretion D) adsorption, active transport and diffusion E) both B and C

13. Which of the following forms the filtration barrier?

A) capillary endothelial cells only B) podocytes only C) basement membrane only D) both capillary endothelial cells and basement membrane E) capillary endothelial cells, basement membrane, and podocytes

14. Which of the following statements is/are correct?

A) The primary filtrate created by glomerular filtration represents 20 % of everything in the blood plasma.

B) Tubular secretion occurs mainly by passive Starling-Landis forces. C) Glomerular filtration occurs by passive Starling-Landis forces. D) Tubular reabsorption occurs only by simple diffusion. E) None of the above are correct.

15. Which is FALSE regarding the Starling Forces involved in glomerular filtration:

A) Bowmans capsule oncotic pressure is not a major determinant of filtration B) Glomerulus capillary hydrostatic pressure is higher than in systemic capillaries C) Net filtration pressure is lower than seen in systemic capillaries D) Efferent arteriole resistance is an important factor which determines glomerulus

capillary hydrostatic pressure E) Both B and D are false

16. Which of the following would increase glomerular filtration rate (GFR)?

A) Vasoconstriction of the afferent arteriole B) Vasodilation of the afferent arteriole C) Vasoconstriction of the efferent arteriole D) Vasodilation of the efferent arteriole E) Both B and C

Test continues on the next page 17. Which of the following substances is NOT secreted at any point into the renal tubules?

A) choline


B) creatinine C) potassium D) hydrogen E) sodium

18. Most reabsorption in the nephron occurs in the ________ and is ________. A) proximal tubule : regulated B) proximal tubule : not regulated C) distal tubule and collecting duct : regulated D) distal tubule and collecting duct : not regulated E) loop of Henle : regulated

19. Calculate renal clearance of X given the following information: urine flow rate = 5 mL/min, plasma concentration of X = 10 mg/mL, urine concentration of X = 50 mg/mL. A) 50 mg/min B) 25 mg/min C) 4 mg/min D) 50 mL/min E) 25 mL/min

20. If the renal clearance ratio of a substance is 0.01 we can conclude that:

A) it is subject to 100% reabsorption B) it is subject to 10% reabsorption C) it is subject to 99% reaborption D) it is subject to 90% net reabsorption E) it is secreted at a rate 10% higher than GFR

21. If X is a substance which is totally cleared from the plasma, then its clearance rate is equal

to: A) The urine flow rate. B) Its excretion rate. C) The glomerular filtration rate. D) The renal plasma flow rate. E) None of the above.

22. Antidiuretic hormone binds to receptors on ________ cells in the collecting ducts and

distal tubules where it ________. A) granular : causes vesicles with aquaporin-2 to insert into the apical membrane B) intercalated : causes vesicles with aquaporin-3 to insert into the apical membrane C) intercalated : causes vesicles with aquaporin-2 to insert into the basolateral membrane D) principal : causes insertion of aquaporin-2 into the apical membrane E) principal : causes vesicle with aquaporin-3 to insert into the apical membrane

Test continues on the next page 23. If both circulating aldosterone and ADH are low, the urine excreted would have which

of the following properties? A) devoid of ions and large volume


B) high osmolarity and low volume C) low osmolarity and low volume D) low osmolarity and large volume E) high osmolarity and large volume

24. What is the strongest stimulus for the release of antidiuretic hormone (ADH) from the posterior pituitary? A) decrease in plasma osmolarity B) increase in blood volume C) increase in plasma osmolarity D) increase in blood pressure E) decrease in sodium content of the blood

25. What role do the macula densa cells have in controlling renin release?

A) They release renin in response to an increase in mean arterial pressure B) They release renin in response to a decrease in mean arterial pressure C) They detect changes in the pressure of afferent arterioles, and communicate these changes to juxtaglomerular cells, which secrete renin D) They detect changes in the pressure of efferent arterioles, and communicate these changes to juxtaglomerular cells, which secrete renin E) They detect changes in the amount of sodium and chloride in the distal tubules, and communicate these changes to juxtaglomerular cells, which secrete renin

26. Which of the following determines the final urines peak (or highest possible) osmolarity?

A) The amount of fluid filtrated at the glomerulus B) The highest osmolarity in the kidney medulla osmotic gradient C) The amount of secretion in the proximal tubule D) Water intake E) None of the above

27. Saltatory propagation is:

A) the main mechanism for synapse neurotransmitter release B) how action potential leap from one Node of Ranvier to another C) a way to greatly increase axonal transmission D) not dependent on myelin E) both B and C

Test continues on the next page 28. Which of the following factors is the largest contributor to the negative resting membrane

potential of about -70 mV in a typical cell? A) The high concentration of Na+ in the E.C.F. B) The high anion concentration in the I.C.F. C) The greater conductance of the membrane to K+ than to Na+.


D) The electrogenic action of Na+, K+ ATPase which exports more positive charge than it imports.

E) The greater tendency for Cl- to diffuse in than for K+ to diffuse out of the cell.

29. What membrane potential (EM) would be needed to maintain extracellular [Na+] = 145 mM and intracellular [Na+] =15 mM at equilibrium.

A) -90 mV. B) 0 mV. C) + 60 mV. D) -80 mV E) -70 mV

30. A movement of the membrane potential from +30 mV to 0 mV is correctly termed: A) An overshoot potential. B) A depolarization. C) A repolarization. D) A hyperpolarization. E) A voltage clamp.

31. A graded potential:

A) Is a relatively small change in membrane potential. B) Is due to changes in conductance of K+, Na+ and Cl-. C) Occurs at axons. D) Is only depolarising. E) Both A and B are correct

32. After the peak of an action potential, repolarization occurs because A) of the delayed opening of Na+ channels. B) of the delayed opening of K+ channels. C) of the delayed opening of Cl- channels. D) of the delayed closing of Cl- channels. E) of the delayed closing of K+ channels.

33. Which statement is FALSE regarding the relative refractory period? A) It last longer than the absolute refractory period B) An A.P. can be generated during this period but with a grater than normal stimulus C) A period where voltage-gated Na+ channels can be reopened D) Represents the Na-inactivation period E) None of the above are false


34. If a long-lasting summed G.P. holds the membrane of the initial segment above threshold for a very long time

A) The neuron will run out of Na+ and K+ B) A.P will keep firing separated by a refractory period C) Larger and larger A.P. will be generated


D) The frequency of A.P. will increase until they start to overlap E) Both B and C

35. Which of the following is /are not true difference(s) between A.P.s and G.P.s

A) their typical size. B) their typical duration. C) their location of origin. D) only the A.P. follows the all-or none rule; the G.P. does not. E) only the A.P. involves the movement of Cl-.

THE END OF THE TEST!

biology 2a03 quiz2 2011a

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