L4 QS BANK, BMS204 PDF Quiz on Cardiac Properties

Okay, here is a 30-MCQ quiz based on the provided lecture: Quiz on Cardiac Properties Part One: Simple MCQs 1. What is the ability of cardiac fibers to respond to adequate stimuli and generate action potentials? a) Contractility b) Excitability c) Conductivity d) Rhythmicity 2. What is the restin...

Okay, here is a 30-MCQ quiz based on the provided lecture: Quiz on Cardiac Properties Part One: Simple MCQs 1. What is the ability of cardiac fibers to respond to adequate stimuli and generate action potentials? a) Contractility b) Excitability c) Conductivity d) Rhythmicity 2. What is the resting membrane potential of a cardiac muscle fiber? a) -20 mV b) -40 mV c) -60 mV d) -90 mV 3. What causes the rapid depolarization phase (phase 0) of a cardiac action potential? a) Potassium influx b) Calcium influx c) Sodium influx d) Chloride efflux 4. What is the primary cause of the plateau phase (phase 2) in a cardiac action potential? a) Potassium influx b) Calcium influx c) Sodium influx d) Chloride efflux 5. What is the duration of the plateau phase in ventricular muscle? a) 100 msec b) 150 msec c) 200 msec d) 300 msec 6. What is the period during which an excitable tissue will not respond to another stimulus called? a) Refractory period b) Latent period c) Relaxation period d) Depolarization period 7. What is the period during which no stimulus, regardless of its strength, can re-stimulate the excitable tissue called? a) Absolute refractory period b) Relative refractory period c) Supernormal phase d) None of the above 8. What is the ability of the heart muscle to contract and relax, performing mechanical work called? a) Contractility b) Excitability c) Conductivity d) Rhythmicity 9. What is the law that states that the greater the initial length of a cardiac muscle fiber, the greater the force of contraction? a) Frank-Starling law b) Boyle's law c) Ohm's law d) Newton's law 10. What is the term for the filling of the ventricles during diastole? a) End-diastolic volume b) End-systolic volume c) Stroke volume d) Cardiac output Part Two: Complex MCQs 11. What is the significance of the long absolute refractory period in cardiac muscle? a) Allows for sustained contraction b) Prevents tetanus and allows for proper filling of the heart chambers c) Increases heart rate d) Decreases the force of contraction 12. What is the role of calcium in cardiac muscle contraction? a) Triggers the release of neurotransmitters b) Blocks the myosin binding sites on actin c) Binds to troponin, leading to the sliding of actin and myosin filaments d) None of the above 13. What is the effect of sympathetic stimulation on cardiac properties? a) Increases heart rate, excitability, conductivity, and contractility b) Decreases heart rate, excitability, conductivity, and contractility c) Increases heart rate but decreases contractility d) No effect 14. What is the effect of parasympathetic stimulation on cardiac properties? a) Increases heart rate, excitability, conductivity, and contractility b) Decreases heart rate, excitability, conductivity, and contractility of the atria only c) Increases heart rate but decreases contractility d) No effect 15. What is the effect of moderate warming on cardiac properties? a) Increases heart rate, excitability, conductivity, and contractility b) Decreases heart rate, excitability, conductivity, and contractility c) Increases heart rate but decreases contractility d) No effect 16. What is the effect of hyperkalemia (increased potassium levels) on cardiac properties? a) Increases heart rate, excitability, conductivity, and contractility b) Decreases heart rate, excitability, conductivity, and contractility c) Increases heart rate but decreases contractility d) No effect 17. What is the effect of hypercalcemia (increased calcium levels) on cardiac properties? a) Increases heart rate, excitability, conductivity, and contractility b) Decreases heart rate, excitability, conductivity, and contractility c) Increases heart rate but decreases contractility d) No effect 18. What is the effect of hypoxia (decreased oxygen levels) on cardiac properties? a) Increases heart rate, excitability, conductivity, and contractility b) Decreases heart rate, excitability, conductivity, and contractility c) Increases heart rate but decreases contractility d) No effect 19. What is the effect of hypercapnia (increased carbon dioxide levels) on cardiac properties? a) Increases heart rate, excitability, conductivity, and contractility b) Decreases heart rate, excitability, conductivity, and contractility c) Increases heart rate but decreases contractility d) No effect 20. What is the effect of acidosis (decreased pH) on cardiac properties? a) Increases heart rate, excitability, conductivity, and contractility b) Decreases heart rate, excitability, conductivity, and contractility c) Increases heart rate but decreases contractility d) No effect 21. What is the role of the sodium-potassium pump in cardiac muscle fibers? a) Maintains the resting membrane potential by pumping sodium out and potassium in b) Transports calcium into the sarcoplasmic reticulum c) Generates ATP for muscle contraction d) None of the above 22. What is the role of the sarcoplasmic reticulum (SR) in cardiac muscle contraction? a) Stores and releases calcium ions b) Produces ATP for muscle contraction c) Removes sodium from the cell d) All of the above 23. What is the role of T-tubules in cardiac muscle contraction? a) Conduct action potentials to the interior of the muscle fiber b) Store calcium ions c) Remove sodium from the cell d) All of the above 24. What is the significance of the plateau phase in the cardiac action potential? a) Allows for rapid repolarization b) Prevents tetanus and allows for proper ejection of blood c) Shortens the refractory period d) None of the above 25. What is the relationship between the mechanical response and the action potential in cardiac muscle? a) The mechanical response lasts longer than the action potential b) The action potential lasts longer than the mechanical response c) They have the same duration d) No relationship 26. What is the significance of Starling's law of the heart? a) Ensures that the heart ejects all the blood that returns to it b) Prevents blood from stagnating in the heart c) Maintains a balance between venous return and cardiac output d) All of the above 27. What is the effect of catecholamines on cardiac properties? a) Increase all cardiac properties b) Decrease all cardiac properties c) No effect d) None of the above 28. What is the effect of cholinergic stimulation on cardiac properties? a) Increase all cardiac properties b) Decrease all cardiac properties c) No effect d) None of the above 29. What is the effect of bacterial toxins on cardiac properties? a) Increase all cardiac properties b) Decrease all cardiac properties c) No effect d) None of the above 30. What is the significance of the "all-or-none" rule in cardiac muscle contraction? a) Allows for graded contractions b) Ensures efficient pumping of blood c) Increases heart rate d) None of the above Answer Guide 1. b 2. d 3. c 4. b 5. d 6. a 7. a 8. a 9. a 10. a 11. b 12. c 13. a 14. b 15. a 16. b 17. a 18. a 19. a 20. b 21. a 22. a 23. a 24. b 25. a 26. d 27. a 28. b 29. b 30. b Done