CARDIOVASCULAR SYSTEM

Transcription

1 CARDIOVASCULAR SYSTEM 1. Resting membrane potential of the ventricular myocardium is: A. -55 to-65mv B to-75mv C. -75 to-85mv D. -85 to-95 mv E. -95 to-105mv 2. Regarding myocardial contraction: A. Initial rapid depolarization & overshoot is due to opening of slow sodium channels. B. T tubules is a storage site for calcium ions C. Duration of atrial myocardial contraction is longer than that of ventricular muscle D. Calcium diffuse passively out of the myocardium to terminate the contraction phase E. During tachycardia, myocardial contraction & relaxation phase are shortened equally. 3. Regarding isovolumic contraction phase: A. It begins as the mitral valve closes B. It follows ventricular ejection phase C. It coincides with the dicrotic notch D. It coincides with the occurrence of 'v' wave of the JVP. E. It is followed by atrial systole 4. "COO wave of the JVP occurs during: A. Atrial contraction B. Beginning of ventricular systole C. End of ventricular systole D. Isovolumic relaxation 5. Which of the following statement is FALSE? A. 70% of ventricular emptying occurs in the 1 st 1/3 of the period of ejection B. 30% of ventricular emptying occurs in the latter 2/3 of the period of ejection C. Atrial contraction occurs at the last 1/3 of the ventricular diastole D. Normal ejection fraction is about 50% E. When the heart contracts strongly, end systolic volume may reduce to 10-20m!. 6. Which of the following statement is CORRECT? A. Contraction of papillary muscle causes mitral & tricuspid valves to close. B. Papillary muscles contract independently to the remainder of myocardium C. Aortic & pulmonary valves are not attached to papillary muscle or chordae tendinae D. All of the above CARDIOVASCULAR PHYSIOLOGY - MCQ

2 7. Regarding cardiac output: A. Baseline sympathetic outflow maintains cardiac output 30% higher than that of the denervated heart. B. Strong vagal stimulation can reduce cardiac output by 50%. C. Duration of systole shortens during increased sympathetic outflow D. All the above are false E. All the above are true 8. Bradycardia occurs with: A. Hypercalcaemia B. Hypematraemia C. Hyperkalaemia D. Hyperthermia 9. Regarding prepotential: A. Its low resting membrane potential is due to a moderate amount of sodium channels being open at rest. B. It is initiated by opening of sodium channels C. It's slope is increased by increased vagal tone D. It's slope is reduced by increased sympathetic tone are true 10. A V nodal delay is: A seconds B seconds C seconds D seconds E seconds II. The following part of the circulation holds the largest percentage of total blood volume B. Pulmonary circulation C. Arteries D. Capillaries E. Veins 12. The following part of the circulation has the largest cross sectional area: A. aorta B. arteries C. capillaries D. venules E. veins CARDIOVASCULAR PHYSIOLOGY - MCQ 2

3 13. Regarding Blood flow in the capillary: A. It is continuous B. Viscosity decreases along the length of the capillary C. Velocity is constant along the length of the capillary D. It displays the Fahraeus-Lindquist effect. 14. Turbulent flow in a vessel is likely to occur with: A. Increased viscosity of the blood B. Decreased diameter of the vessel C. Increased density of the blood D. Decreased velocity of the blood 15. Blood flow rate increases when: A. radius of the vessel decreases B. length of the vessel decreases C. hematocrit increases D. blood pressure decreases 16. Increased pulse pressure occurs in the following condition EXCEPT: A. Aortic sclerosis B. Arteriolosclerosis C. Patent ductus arteriosus D. Aortic regurgitation 17. Right atrial pressure: A. is larger than central venous pressure B. is normally 8 mmhg C. increases with increased myocardial contractility D. is same as venous pressure in the feet in a supine patient are incorrect 18. Which of the following structure is a blood reservoir? A. Spleen B. Liver C. Lungs D. Veins CARDIOVASCULAR PHYSIOLOGY - MCQ 3

4 19. The following body tissue does not have lymphatic channels: B. Dermis C. Bone D. Kidneys E. Thyroid 20. Total body lymphatic flow rate is: A. 1.2 ml/hour B. 12 mllhour C. 120 ml/hour D mllhour E. none of the above 21. Acute control ofbp does NOT include: A. Activation of the sympathetic nervous system B. Activation of the angiotensin C. Activation of release of antidiuretic hormone D. Activation of release of aldosterone 22. Vasoconstrictor substances include the following EXCEPT: A. Adrenaline B. Serotonin C. Endothelin D. Angiotensin E. Vasopressin 23.The following ions are all vasodilators EXCEPT: A. Calcium ion B. Sodium ion C. Potassium ion D. Magnesium ion E. Hydrogen ion 23. Which of the following arterial pressure reflex operates at the BP range 0-60mmHg: A. Baroreceptor reflex B. Abdominal compression reflex C. Pulmonary arterial reflex D. Bainbridge reflex E. CNS ischemic response CARDIOVASCULAR PHYSIOLOGY - MCQ 4

5 24. Normal cardiac index is: A. 3 mllmin/m 2 B. 30 ml/minlm 2 C. 300 mllminlm 2 D ml/minlm Which of the following organ has the highest O2 extraction ratio? B. Brain C. Kidney D. Skin E. Gastrointestinal tract 26. Which of the following organ has the largest relative blood flow? A. Kidney B. Brain C. Heart D. Skin E. Carotid bodies 27. Cerebral blood flow is increased with: A. 1'PaC02 B. 1'Pa02 C. 1'pH D. All of the above 2S. Which of the following is the most effective at constricting renal efferent arteriole in normal physiologic doses? A. Adrenaline B. Angiotensin II C. Angiotensin III D. EDRF E. Prostaglandin ANSWERS: 1. D 7. E 13. D 19. C 25. A 2. B S. C 14. C 20.C 26. E 3. A 9. A 15. B 21. D 27. A 4. B 10. C 16. A 22.B 2S. B 5. D 6. C 11. E 12. C 17. D IS. E 23. E 24.D CARDIOVASCULAR PHYSIOLOGY - MCQ 5