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Cardiovascular system

Cardiovascular system

1- All ventricular muscle cells beat at the same time because: 1) They are supplied by the vagus nerve. 2) Their number is small. 3) They are supplied by sympathetic nerves. 4) They are connected to each other by intercalated disc. 2- All the following describe the cardiac muscle EXCEPT: 1) It is a functional syncitium. 2) It is an anatomical syncytium. 3) It exhibits myogenic rhythmicity. 4) It is striated. 3- Starling’s law of the heart states that the strength of contraction is proportional to: 1) Myocardial oxygen supply. 2) Stroke volume. 3) The end diastolic volume. 4) Arterial blood pressure. 4- About the cardiac muscle all the following are true EXCEPT: 1) Low electric resistance of the membrane at the intercalated discs. 2) Form true syncytium. 3) Obeys the all or none law. 4) There is almost a special capillary for each fibre. 5- Myocardial contractility is best correlated with the intracellular concentration of: 1) Na+. 2) K+. 3) Ca++. 4) Cl-. 6- The following agents have +ve inotropic on the heart EXCEPT: 1) Norepinephrine. 2) Digitalis. 3) Glucagon. 4) Acetylcholine.

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Cardiovascular system

7- The important function of cardiac purkinje system is to: 1) Slow the conduction of impulses. 2) Increase the conduction of impulses. 3) Amplify the cardiac impulses. 4) Increase the force of ventricular contraction. 8- Chronotropism refers to: 1) Rhythmicity. 2) Conductivity. 3) Excitability. 4) Contractility. 9- About the cardiac conductivity, all the following are true EXCEPT: 1) It is slowest in the A-V node. 2) It is maximal in the Purkinje fibres. 3) It is slowest in the ventricular muscle. 4) It is decreased by vagal stimulation. 10- Sympathetic stimulation cause all of the following in the heart EXCEPT: 1) It increases the heart rate. 2) It decreases the permeability of S.A.N. to K+. 3) It decreases the slope of the prepotential. 4) It decreases the conduction time in the A.V.N. 111) 2) 3) 4)

The pacemaker potential is due primarily to a : Slow decrease in K+ permeability. Slow increase in K+ permeability. Slow decrease in Na+ permeability. Rapid increase in Ca++ permeability.

121) 2) 3) 4)

Atrial fibrillation leads to: Ventricular fibrillation. Irregular pulse with pulse deficit. Nodal rhythm. Ventricular bradycardia.

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Cardiovascular system

13- The upstroke limb of the action potential in SAN cells is in response to: 1) Opening of voltage gated Na+ channels. 2) Opening of T-Ca++ channels. 3) Opening of L-Ca++ channels. 4) Opening of voltage gated K+ channels. 141) 2) 3) 4)

About the A.R.P. in the heart, all the following is true EXCEPT: It lasts approximately as long as the cardiac contraction. It is longer than the A.R.P. of skeletal muscle. It corresponds in time with the whole duration of the action potential. During it, the heart can not be stimulated.

151) 2) 3) 4)

About cardiac contractility, all the following is true EXCEPT: It depends on interaction between actin & myosin. It increases when the serum K+ rises above normal. It is lost if the bathing medium is made Ca++ -free. It decreases by local application of acetyl choline.

16- In the heart, parasympathetic stimulation causes all of the following effects EXCEPT: 1) Decreased rate of discharge from the S.A.N. 2) Coronary V.C. 3) Increased ventricular contractility. 4) Decreased atrial contractility. 171) 2) 3) 4)

About the pacemaker potential, all the following is true EXCEPT: Its amplitude is –80 to –90 mV. It is unstable. Its slope is decreased by increased permeability to K+. The firing level occurs at a potential difference of about –45 mV.

181) 2) 3) 4)

The phase of cardiac cycle at which the heart is not responsive: Is the absolute refractory period. Is the relative refractory period. Is shorter than that in the skeletal muscle. Extends all through the action potential.

47


Cardiovascular system 191) 2) 3) 4)

The S.A.N. is the normal pacemaker because of its: Rate of impulse discharge. Location in the atrium. Neural control. Muscular structure.

201) 2) 3) 4)

The cardiac tissue with the slowed rhythmicity is the: S.A.N. without vagal tone. S.A.N. with vagal tone. Ventricular muscle. Purkinje fibres.

211) 2) 3) 4)

A ventricular extrasystole: Is usually not followed by a compensatory pause. Always indicates a serious heart disease. May fail to produce a pulse at the wrist. Is usually not followed by post extrasystolic potentiation.

22- Regarding initiation & propagation of cardiac impulse, all are true EXCEPT: 1) The action potentials in the heart are about 100 times longer than those of skeletal muscles. 2) The cells of the SA-node have a steady resting potential of - 90 mV. 3) The spread of cardiac excitation is delayed by about 0.1 sec. at AVN. 4) The conducting tissue of the heart is composed of specialized cardiac myocytes linked by gap junctions. 231) 2) 3) 4)

Contractile response of cardiac muscle: Obeys the all or none law. Starts at the same time of electric excitation. Is triggered by the release of Ca++ from SR as in skeletal muscle. Last for the same time as its action potential.

24- In an ECG recording, the time between atrial depolarization & ventricular depolarization is represented by the: 1) P-wave. 2) QRS complex. 3) S-T interval. 4) P-R segment.

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Cardiovascular

system 25- Concerning the ECG of an adult human, all are true EXCEPT: 1) 2) 3) 4) 261) 2) 3) 4)

The P-wave coincides with depolarization of the atria. P-R interval of 0.3 seconds indicates impaired conduction. The R-wave coincides with depolarization of the apex of the heart. The Q-wave coincides with depolarization of the atria. Suppression of activity in the SA-node of a normal heart result in: Prolongation of P-R interval. Shortening of the Q-T interval. A-V node becomes the pace maker of the heart. Normal P-wave.

27- At a heart rate of 72 beats per minute, the longest ECG interval would be: 1) Duration of the P-wave. 2) Duration of the QRS complex. 3) P-R interval. 4) Q-T interval. 281) 2) 3) 4)

In the ECG, the T-wave is associated with: Atrial depolarization. Atrial repolarization. Ventricular depolarization. Ventricular repolarization.

29- A person’s ECG has no P-wave, but a normal QRS & T-wave. His pace maker is located in: 1) SA-node. 2) AV-node. 3) Bundle of His. 4) Purkinje system. 30- An ECG shows no P-waves in any leads. This indicates that impulses from which one are blocked: 1) SA-node. 2) Bundle of His. 3) Purkinje fibres. 4) Ventricular muscle.

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Cardiovascular system 311) 2) 3) 4)

During a first degree AV-nodal block: Most P-waves would be followed by QRS complex. QRS complex would last longer than. Heart rate would be lower than normal. The P-R interval would be longer than normal.

321) 2) 3) 4)

A complete heart block is recognized in ECG by: Prolonged P-R interval. Prolonged QRS complex. Dissociation of atria & ventricles. Irregular pulse rate.

331) 2) 3) 4)

Prolongation of A-V conduction time is recognized in ECG by: Long, flat P-wave. P-R interval exceeding 0.21 seconds. QRS complex exceeding 0.12 seconds. T-wave exceeding 0.12 seconds.

341) 2) 3) 4)

A first degree A-V block in ECG shows: A more rapid atrial than ventricular rate. Inverted P-waves in the bipolar limb leads. QRS complex duration exceeds 0.12 sec. Prolonged P-R interval.

35- Which of the following statements about the ECG is TRUE: 1) Einthoven’s law states that the sum of voltages in lead I & II equal lead III. 2) Lead III recording electrodes are placed on right arm & left leg. 3) Augmented limb leads measure potential between 2 limbs. 4) Augmented limb leads measure potential between one limb & two other limbs. 361) 2) 3) 4)

In normal ECG: P-wave is associated with the repolarization of atria. QRS complex immediately follows contraction of the ventricles. T-wave is due to depolarization of the ventricles. S-T segment corresponds to the plateau of the action potential.

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Cardiovascular system

37- An ECG showing a ratio of three P-waves to each QRS complex indicates: 1) Sinus arrhythmia. 2) First degree A-V block. 3) Second degree A-V block. 4) Third degree A-V block. 38- A condition known as complete heart block is characterized by the following changes: 1) The ratio of P-waves to QRS complex is 1:1. 2) The atria beat regularly. 3) Prolonged P-R interval. 4) Ventricles beat slowly & irregularly. 39- The pattern of ECG during ventricular premature beat (extrasystole) is characterized by: 1) Raised S-T segment. 2) Prolonged QRS complex with high voltage. 3) Not followed by compensatory pause. 4) If it is due to ectopic focus on the right side it causes right axis deviation. 401) 2) 3) 4)

The electrocardiographic lead aVR is best described as: Unipolar. Bipolar. Augmented unipolar. Augmented bipolar.

411) 2) 3) 4)

Wolf-Parkinson-White syndrome is characterized by: Abnormal conduction between atria & ventricle cause short P-R interval. Cause increase rate of conduction in AV-node till one beat drops. Prolonged P-R interval till one beat drops. Associated with first degree heart block.

421) 2) 3) 4)

Deep Q-wave in the ECG indicates that there is: Heart block. Injury current. Electric window. Ischemia.

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Cardiovascular system 431) 2) 3) 4)

The duration of cardiac cycle with a heart rate of 75 beat/minute is: 2.0 seconds. 0.2 seconds. 0.8 seconds. 1.5 seconds.

44- During the isometric contraction phase of cardiac cycle, the ventricular volume: 1) Decreases. 2) Increases. 3) Remains unchanged. 4) Decreases as the intraventricular pressure increases. 45- During cardiac cycle in normal human: 1) The left ventricle eject more blood per beat than the right ventricle. 2) The mitral valve opens when the left atrial pressure exceeds the left ventricular pressure. 3) The pulmonary valve opens when the right ventricular pressure reach 25 mm Hg. 4) During diastole, the left ventricular pressure is about 80 mm Hg. 461) 2) 3) 4)

With respect to cardiac cycle, all are true EXCEPT: Aortic valve opens at the end of isometric contraction of left ventricle. 3rd heart sound occurs at end of reduced filling phase (diastasis). T-wave of ECG ends at time of aortic valve closure. “a� wave of venous pulse coincides with 4th heart sound.

471) 2) 3) 4)

During atrial systole of the cardiac cycle: The first heart sound occurs. Over 70 % of ventricular filling occurs. The A-V valves are closed. The aortic valve is closed.

481) 2) 3) 4)

During the ventricular ejection phase of cardiac cycle. Second heart sound occurs. QRS complex of ECG occurs. Atrial contraction continues. A-V valves are closed.

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Cardiovascular

system 49- Ventricular pressure is higher than the atrial pressure in all phases of the cardiac cycle EXCEPT in: 1) Isometric contraction phase. 2) Atrial systole phase. 3) Maximum ejection phase. 4) Reduced ejection phase. 501) 2) 3) 4)

Diacrotic notch is due to: Sudden closure of AV valves. Sudden closure of aortic valve. Sudden decrease in aortic pressure. Marked decrease in ventricular pressure.

511) 2) 3) 4)

AV valves are opened in: Isometric contraction phase. Atria systole phase. Protodiastolic phase. Maximum ejection phase.

521) 2) 3) 4)

Systolic pressure in right ventricle is: 35 mmHg. 26 mmHg. 15 mmHg. 45 mmHg.

531) 2) 3) 4)

The first heart sound occurs synchronously with: A rise in ventricular pressure. A fall in atrial pressure. The P-wave of ECG. Closure of the aortic & pulmonary valves.

541) 2) 3) 4)

Cannon waves in jugular venous pulse are: A special from of V-wave. Seen in complete heart block. Associated with second degree heart block. Associated with atrial fibrillation.

53


Cardiovascular system 551) 2) 3) 4)

During the isovolumetric contraction phase of the cardiac cycle: The ventricular pressure is decreased. The ventricular volume is increased. The coronary blood flow is decreased. The atrial pressure is unchanged.

56- During the maximum ejection phase, all the following is true EXCEPT: 1) The first heart sound is heard. 2) The T-wave of the ECG is at its peak. 3) The ventricular volume is decreased. 4) The ventricular pressure reaches maximum. 57- The time from the upstroke of the radial artery pulse to the incisura is a measure of the period of: 1) Atrial diastole. 2) Ventricular ejection. 3) Rapid ventricular filling. 4) Ventricular isovolumetric relaxation. 581) 2) 3) 4)

About the first heart sound, all the following is true EXCEPT: It is mainly caused by turbulence set up by closure of The A.V. valves. It is more longer in duration than the second heart sound. It is coincides with the P wave of the ECG. Its frequency (pitch) is lower than that of the second heart sound.

591) 2) 3) 4)

About the second heart sound, all the following is true EXCEPT: It occurs during the rapid (maximum) ejection phase. It marks the end of systole. It is shorter & of a higher Pitch than the first heart sound. It is due to closure of the semilunar valves.

601) 2) 3) 4)

The A wave of the J.V.P. is caused by: Pacemaker potential. Atrial depolarization. Ventricular repolarization. Atrial contraction.

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Cardiovascular

system 61- About the A wave of the J.V.P., all the following is true EXCEPT: 1) 2) 3) 4)

It is absent in atrial fibrillation. It is absent in both supraventricular & ventricular premature beats. It is exaggerated in 3rd degree A-V block causing cannon waves. It is exaggerated in tricuspid stenosis.

621) 2) 3) 4)

Concerning the radial pulse: It depends upon the blood flow for its propagation. it travels at a rate that is slower than that of the blood flow. Its anacrotic limb is synchronous with the rapid ejection phase. Its dicrotic notch is synchronous with closure of the aortic valve.

631) 2) 3) 4)

Jugular venous pulse simulates: Right atrial pressure in the cardiac cycle. Left atrial pressure in the cardiac cycle. Left ventricular pressure in the cardiac cycle. Right ventricular pressure in the cardiac cycle.

641) 2) 3) 4)

C wave in jugular venous pulse occurs in: Isometric contraction phase. Isometric relaxation phase. Maximum ejection phase. Atrial systole phase.

651) 2) 3) 4)

Cannon waves appear in: Complete heart block. AV nodal rhythm. Ventricular extrasystole. All of the above.

661) 2) 3) 4)

Diacrotic wave is caused by: Escape of blood from the aorta to the periphery. Elastic recoil of the aorta leading to increased aortic pressure. Aortic regurgitation of blood. Increase aortic distention.

671) 2) 3) 4)

Water hummer pulse occurs in: Arteriosclerosis. Hyperthyroidism. Aortic regurgitation. All of the above.

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Cardiovascular system 681) 2) 3) 4)

The systolic pressure in the left ventricle is: 130 mmHg. 110 mmHg. 150 mmHg. 80 mmHg.

69- Which of the following is mainly concerned with regulation of heart rate and blood pressure? 1) Alam-Smirk reflex. 2) Marey’s law. 3) Starling law. 4) None of the above. 701) 2) 3) 4)

In respiratory sinus arrhythmia, the heart rate: Is regular. Increases during inspiration. Decreases during inspiration. Increases during expiration.

711) 2) 3) 4)

Respiratory sinus arrhythmia is a: Pathological condition. Normal phenomenon. Disease of SA node. Disease of conducting system.

721) 2) 3) 4)

Buffer nerves are branches of: Vagus and glossopharyngeal nerves. Trigeminal nerves. Facial nerves. None of the above.

731) 2) 3) 4)

The first heart sound coincides with: Isometric contraction phase. Isometric relaxation phase. Ejection phase. Protodiastolic phase.

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Cardiovascular

system 74- Persistence of a patent ductus arteriosus following birth causes: 1) 2) 3) 4)

Diastolic murmur. Systolic murmur. Continuous murmur. Gallop rhythm.

751) 2) 3) 4)

Increasing vagal stimulation of the heart will cause an increase in: Heart rate. P-R interval. Ventricular contractility. Ejection fraction.

761) 2) 3) 4)

Blood pressure increases and heart rate decreases in response to: Exercise. Increased body temperature. Exposure to high altitude. Increased intracranial tension.

771) 2) 3) 4)

Trigger zones include all these areas EXCEPT: Eye ball. Larynx. Epigastrium. Apex of the heart.

781) 2) 3) 4)

all of the following decrease the cardiac output EXCEPT: Increased vagal activity. Rapid paroxysmal tachycardia. Increased end-diastolic volume. Standing up from the recumbent position.

791) 2) 3) 4)

The cardiac output: Is the combined blood volumes pumped by both ventricles/minute. Increases when there is overstretch of the ventricle. Matches the venous return in a normal heart. Falls when a person with heart failure is given digitals.

801) 2) 3) 4)

The cardiac reserve refers to the increase than can be attained in the: Cardiac work. Cardiac output. Stroke volume. All of the above.

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Cardiovascular

system 81- Within physiological limits, if the EDV is increased: 1) 2) 3) 4)

The force of cardiac contraction is increased. The stroke volume is increased. The cardiac output is increased. All of the above.

821) 2) 3) 4)

The cardiac index is the ratio of the: Cardiac output and surface area. Cardiac output and body weight. Cardiac output and work of the heart. Stroke volume and body weight.

831) 2) 3) 4)

Cardiac output is decreased: On standing up. During stimulation of sympathetic to the heart. By increasing the end-diastolic volume of the heart. On cutting the vagal nerve to the heart.

841) 2) 3) 4)

Stroke volume is increased by all of the following EXCEPT: Sympathetic stimulation. Decreased venous return. Digitals. Stretched cardiac muscle fibres.

851) 2) 3) 4)

an average man at rest has a stroke volume that is: Greater from the left ventricle than the right ventricle. Equal to cardiac output divided by the heart rate. Independent of body surface area. 100-120 ml.

861) 2) 3) 4)

All of the following increases COP, EXCEPT: Increased end-diastolic volume. Valsalva maneuver. Increase venous return. Moderate tachycardia.

871) 2) 3) 4)

All of the following increases the stroke volume EXCEPT: Increase the venous return. During moderate exercise. Increase the end-diastolic volume. Marked tachycardia.

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Cardiovascular system 88- The COP: 1) 2) 3) 4)

Is determined by the end-systolic pressure X heart rate. Equals ½ venous return. Increased at very slow hart rate. Increased by the action of +ve inotropic factors.

891) 2) 3) 4)

The cardiac output: Increases on standing. Increases by administration of adrenergic blocking agents. Increases by catecholamine. Is necessary increased when the heart rate increases.

901) 2) 3) 4)

Venous return to the heart is increased by: Vasodilatation. Increase the right atrial pressure. Relaxation of skeletal muscle. Increased negativity of the thoracic pressure.

911) 2) 3) 4)

About the venous return, all the following is true EXCEPT: Sympathetic venomotor tone helps in maintaining it constant. It is the primary controller of COP. It is directly proportional to the right atrial pressure. It is increased by increasing the intrathoracic negativity.

921) 2) 3) 4)

Cardiac reserve mechanism include all the following EXCEPT: Acceleration of the heart rate up to 250/min. Increase the stroke volume. Ventricular hypertrophy. Responsiveness to neural and circulating adrenergic support.

931) 2) 3) 4)

An increased discharge of impulses from the baroreceptors leads to: Stimulation of the vasomotor centre. Stimulation of the cardioinhibitory centre (CIC). Stimulation of the respiratory centre. Increasing the secretion of ADH.

941) 2) 3) 4)

The importance of the vagal tone is to: Increase the arterial B.P. Increase the intestinal secretion. Decrease the breathing rate. Decreases the cardiac activity.

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Cardiovascular system

95- In the heart, parasympathetic stimulation causes all the following effects EXCEPT: 1) Decreased rate of discharge from the S.A.N. 2) Coronary V.C. 3) Increased ventricular contractility. 4) Decreased atrial contractility. 961) 2) 3) 4)

Within physiologic limits, an increase in the right atrial pressure: Decrease the systemic arterial B.P. Increases the cardiac output. Inhibits transmission through the sympathetic ganglia. All of the above.

97- Stimulation of the depressor (cardioinhibitory) area in the medulla oblongata: 1) Inhibits the neighbouring V.C.C. causing V.D. 2) Leads to tachycardia. 3) Inhibits transmission through the sympathetic ganglia. 4) All of the above. 98- The sympathetic V.C. tone is decreased in response to increased activity of the: 1) Carotid sinus baroreceptors. 2) Medullary chemoreceptors. 3) Pain receptors. 4) Carotid body chemoreceptors. 991) 2) 3) 4)

The pulse pressure in a vessel is determined mainly by its: Cross sectional area. Anatomical configuration. Distensibility. Distance from the heart.

1001) 2) 3) 4)

The ratio of cardiac work to the total energy expenditure is: Called the cardiac mechanical efficiency and is normally 15-20%. Called the cardiac index. Constant even during exercise. Not changed by autonomic stimulation.

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Cardiovascular system 1011) 2) 3) 4)

Following constriction of one renal artery: The cardiac output is increased. The blood volume is decreased. The peripheral resistance is increased. The heart rate is increased.

102- The normal level of arterial B.P. is kept constant mainly by the activity of: 1) The baroreceptors in the carotid sinus and aortic arch. 2) Venoconstriction. 3) Accelerated respiration. 4) Activation of the symp. V.D. cholinergic discharge to skeletal muscle. 1031) 2) 3) 4)

In case of haemorrhage, the carotid body chemoreceptors may: Decrease the heart rate. Slow respiration. Increase the arterial B.P. Produce heart block.

1041) 2) 3) 4)

The resistance through blood vessels: Increases 16 times when the radius of the vessel is doubled. Increased in old age due to loss of the arterial wall elasticity. Is directly proportional to the viscosity and length of the vessels. Is less in the systemic vessels than in the pulmonary vessels.

1051) 2) 3) 4)

Diminished arterial wall elasticity would increase: Both the systolic and diastolic B.P. as well as the pulse pressure. The peripheral resistance. The cardiac work and velocity of the arterial pulse wave. The circulation time.

1061) 2) 3) 4)

Angiotensinogen is: A lipoprotein substance. A diuretic substance. A powerful V.C. substance. Activated by renin in the circulation.

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Cardiovascular

system 107- Angiotensin II: 1) 2) 3) 4) 1081) 2) 3) 4)

Is formed by the action of an enzyme on angiotensin III. Is released from the juxtaglomerular apparatus of the kidneys. Acts through stimulating the vasomotor centre. Is formed due to presence of renin in the circulation. The angiotensin converting enzyme (ACE): Is normally absent in the plasma and pulmonary epithelium. Causes arteriolar V.C. It converts angiotensin I into angiotensin II. It converts angiotensinogen into angiotensin I.

109- About mediators and vasoactive substances, all the following is true EXCEPT: 1) Norepinephrine is a neurotransmitter for arteriolar V.C. 2) Acetylcholine and substance P are neurotransmitters for arteriolar V.D. 3) Renin and angiotensin I produce arteriolar V.C. 4) Catecholamines, angiotensin II and vasopressin are circulating V.C. substances. 110- The effects of gravity on the venous return are counteracted mainly by: 1) The pressure gradient. 2) Skeletal muscle contraction and increased noradrenergic discharge that constricts the veins. 3) Arteriolar V.D. 4) Increased heart and respiratory rates. 1111) 2) 3) 4)

About the resistance to blood flow, all the following is true EXCEPT: It is inversely proportional to the 4th power of the radius of the vessel. It is directly proportional to the length of the vessel. It is independent of the thickness of the vessel wall. Is it independent of the haematocrite.

1121) 2) 3) 4)

Left ventricular hypertrophy occurs in the following cases EXCEPT: Aortic regurgitation. Mitral stenosis. Aortic stenosis. Chronic systemic hypertension.

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Cardiovascular system 1131) 2) 3) 4)

The cardiac output: Is necessarily increased when the heart rate increases. Is reflexly reduced on exposure to a high temperature. Is about ½ of maximum when the subject is at rest. Can be measured by using the Fick’s principle.

1141) 2) 3) 4)

The systemic A.B.P.: Decreases with age. Decreases on sudden exposure to cold. Increases on assumption of the upright posture. Increases by brain stem asphyxia.

1151) 2) 3) 4)

Vasodilatation is produced by: Vasopressin. Bradykinin. Angiotensin I. Norepinephrine.

116- Stimulation of the cardiac symp. nerves produces all the following EXCEPT: 1) Increased oxygen consumption by the heart. 2) An increase in the slope of the pacemaker potential in the SAN. 3) Decreased coronary blood flow. 4) Increased cardiac output. 1171) 2) 3) 4)

The systolic A.B.P. is: Unaffected by changes in posture. Directly increased by renin. Affected by the venous return to the heart. Unaffected by the peripheral vascular resistance.

1181) 2) 3) 4)

All the following are expected to increase the heart rate EXCEPT: Thyrotoxicosis. Injection of norepinephrine. Stimulation of the sympathetic nerves that supply the heart. Section of vagal efferent nerves that supply the heart.

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Cardiovascular

system 119- Which of the following conditions causes pulse pressure to increase? 1) 2) 3) 4)

Tachycardia. Arteriosclerosis. Haemorrhage. Aortic stenosis.

120- Systemic arteriolar constriction may results from an increase in the local concentration of which of the following: 1) Nitric oxide. 2) Angiotensin II. 3) Atrial natriuretic peptide. 4) Hydrogen ion. 121- The distribution of blood among the various organs of the body is regulated by regulating the resistance of the: 1) Arteries. 2) Arterioles. 3) Postcapillary venules. 4) Veins. 1221) 2) 3) 4)

Vasodilatation is produced by: Bradykinin. Vasopressin. Norepinephrine. Increase in pH.

123- Local control of circulation predominates over neural in which of the following orans: 1) Brain. 2) Skin. 3) Liver. 4) All of the above. 124- Atrial natriuretic peptide (ANP): 1) Causes retention of sodium. 2) Decreases the responsiveness of the vascular smooth muscle to many V.C. substances. 3) Stimulates the secretion of vasopressin. 4) Causes rise in the arterial blood pressure.

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Cardiovascular

system 125- Concerning the factors which determine the arterial blood pressure, all the following are correct EXCEPT: 1) An increased stroke volume tends to elevate both systolic and diastolic pressure, but the systolic pressure rises more than the diastolic. 2) Arteriolar constriction rises the diastolic pressure more than the systolic pressure. 3) In arteriosclerosis, the systolic pressure increases while the diastolic pressure decreases. 4) Acceleration of the heart with a fixed stroke volume decreases the diastolic pressure. 1261) 2) 3) 4)

Arteriolar constriction may result from: Increased adrenergic discharge. Locally released serotonin. Decreased local temperature. All of the above.

1271) 2) 3) 4)

Which of the following causes vasoconstriction of the arterioles? Increased tissue metabolism. Increased histamine. Increased circulating epinephrine. All of the above.

1281) 2) 3) 4)

Mary’s law states that: Blood pressure and heart rate bear a direct relationship. Blood pressure and heart rate bear a reciprocal relationship. Blood pressure determines glomerular filtration rate. Heart rate and the blood pressure are unrelated.

1291) 2) 3) 4)

During exercise, all the following are increased EXCEPT: Pulse pressure. C.O.P. The blood flow to the heart. Total peripheral resistance.

1301) 2) 3) 4)

Angiotensin II has the following effects EXCEPT: Stimulates antidiuretic hormone release. Stimulates renin release. Is a powerful vasoconstriction. Stimulates aldosterone release.

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Cardiovascular

system 131- The open phase of vasomotion in capillaries is due to: 1) 2) 3) 4)

Oxygen lack & increased carbon dioxide in the tissues. Increased pressure in the draining vein. V.C of the preceding arteriole. Increased arterial blood pressure.

1321) 2) 3) 4)

The plasma colloidal osmotic pressure is: The main filtering force in tissue fluid formation. Determined only by the albumin concentration of the plasma. Equivalent to the osmotic pressure of 0.9% NaCl solution. Normally about 28 mmHg.

1331) 2) 3) 4)

About the dynamics of interstitial fluid formation: Net outward force = 40 mmHg. Net inward force = 9 mmHg. Interstitial fluid pressure = +3 mmHg. Interstitial fluid colloid osmotic pressure = 28 mmHg.

1341) 2) 3) 4)

Lymph flow towards the heart is helped by the following EXCEPT: Contraction of skeletal muscle. Negative intrathoracic pressure during inspiration. Pulsations of the neighboring arteries. Relaxation of walls of large lymphatic ducts.

1351) 2) 3) 4)

The level of plasma proteins at which edema starts to appear is: 7.5 gm%. 5.5 gm%. 3.5 gm%. 4.5 gm%.

1361) 2) 3) 4)

Pitting edema is produced by all the following factors EXCEPT: Renal disease. Congestive heart failure. Liver disease & hypoproteinaemia. Elephantiasis & malignant or inflammatory lymphatic obstruction.

1371) 2) 3) 4)

Edema occurs in all the following conditions EXCEPT: During preganancy. In very hot weather. With arteriolar V.C. In hepatic disease.

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Cardiovascular system 1381) 2) 3) 4)

The tendency for edema to occur will be increased by: Arteriolar constriction. Increased venous pressure. Increased plasma protein concentration. Muscular activity.

1391) 2) 3) 4)

CVP is increased in all these cases EXCEPT in: Congestive heart failure. Hypervolaemia. Standing. Sympathomimetics.

140- Hypotension is prevented in prolonged standing by all the following EXCEPT: 1) Venous constriction. 2) Capillary dilatation. 3) Arterial pulsation. 4) Efficient valves. 1411) 2) 3) 4)

The coronary blood flow in human heart/minute equals: 225 ml. 300 ml. 330 ml. 360 ml.

1421) 2) 3) 4)

The maximal coronary blood flow occurs during the: Early part of systole. Late part of systole. Early part of diastole. End of diastole.

143- The lowest coronary blood flow occurs during which of the following cardiac phases: 1) Maximal ejection phase. 2) Isometric contraction phase. 3) Reduced ejection phase. 4) Atrial systole.

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Cardiovascular

system 144- Anrep’s reflex states that: 1) An increase in the right pressure causes reflex coronary vasodilatation. 2) Distention of stomach with heavy meal produces reflex coronary vasoconstriction. 3) Skeletal muscles activity during exercise stimulate coronary vasodilatation. 4) Increased cardiac output increases coronary blood flow which is helped by decreased vagal tone. 145- Which of the following drugs is NOT used in treatment of angina pectoris? 1) Nitroglycerin. 2) Long acting nitrates. 3) Calcium entry blocking agents. 4) Sympathomimetics. 1461) 2) 3) 4)

The pulmonary capillary blood pressure is: 30 mm Hg. 15 mm Hg. 8 mm Hg. 1 - 4 mm Hg.

147- When the alveolar oxygen concentration becomes low, the adjacent blood vessels will: 1) Dilate. 2) Constrict. 3) Thrombose. 4) Undergo a reactive hyperaemia. 1481) 2) 3) 4)

In normal adult, the brain receives: 500 ml blood / min. 750 ml blood / min. 1000 ml blood / min. 1250 ml blood / min.

149- In the mechanism of Cushing reflex, all the following is true EXCEPT: 1) It occurs when the intracranial tension is elevated to more than 33 mmHg. 2) Cerebral ischemia stimulates the vasomotor area. 3) The arterial blood pressure rises. 4) The heart and respiration accelerate to correct cerebral ischemia.

68


Cardiovascular system

150- Urine volume decreases in a case of hemorrhage due to all of the following EXCEPT: 1) Decreased arterial blood pressure. 2) Decreased blood volume. 3) Decreased ADH secretion. 4) Vasoconstriction of renal blood vessels. 151- A person who has a blood volume equal to 5000 ml may lose, without danger of suffering hypovolumic shock, a maximum of: 1) 500 ml blood (10%). 2) 1000 ml blood (20%). 3) 1500 ml blood (30%). 4) 2000 ml blood (40%). 152- Catecholamine secreted from adrenal medulla due to increased sympathetic discharge in a case of hemorrhage will have the following effects EXCEPT: 1) Vasoconstriction of both arterioles and veins. 2) Increase in heart rate and stroke volume. 3) Increase secretion of glucocorticoids. 4) Increase secretion of antidiuretic hormone. 153- In hemorrhage, the heart rate increased due to all the following causes EXCEPT: 1) Decreased arterial blood pressure. 2) Increased adrenaline secretion. 3) Bainbridge reflex. 4) Hypoxia. 154- Increased heart rate during muscular exercise is due to all the following EXCEPT: 1) Emotional stimuli from the cerebral cortex & hypothalamus. 2) Marey’s law. 3) Bainbridge reflex. 4) Alarm smirk reflex.

69


Cardiovascular system

155- Increased coronary blood flow during exercise is achieved by all the following EXCEPT: 1) Anrep’s reflex. 2) Marked tachycardia. 3) Local vasodilatation by accumulated metabolites. 4) Increased sympathetic stimulation. 1561) 2) 3) 4)

Increased blood flow to active skeletal muscles is due to: Anrep’s reflex. Loven’s reflex. Alarm smirk reflex. Mc Dowall’s reflex.

70


Cardiovascular system

71

Answer Key 1- D 2- B 3- C 4- B 5- C 6- D 7- D 8- A 9- C 101112131415161718192021222324252627282930-

C A B C C B C A A A C C B A D D C D D B A

313233343536373839404142434445464748495051525354555657585960-

D C B D D D C B B C A C C C B B D D B C B B A B C B B C A D

616263646566676869707172737475767778798081828384858687888990-

B C A A D B D A B B B A A C B D D C C D D A A B B B D D C D


Cardiovascular

72

system

919293949596979899100101102103104105106107108109110111112113114115116117118119120-

C A B D C B A A C A C A C C C D D C C B D B D D B C C B B B

121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150-

B A A B D D C B D B A D B D B D C B C B A C B A D C B B D C

151152153154155156-

B D C B B B


mcq >>> cardio