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  • Question 1 - Direct conduction from the atrium to the ventricles is prevented by: ...

    Correct

    • Direct conduction from the atrium to the ventricles is prevented by:

      Your Answer: Annulus fibrosus

      Explanation:

      The annulus fibrosus disconnects the syncytium complex. The atria are rapidly activated however the activation peters out when the insulating layer-the annulus fibrosus-is reached.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14.6
      Seconds

  • Question 2 - The ability of the SA node cells to allow ionic flow through channels...

    Incorrect

    • The ability of the SA node cells to allow ionic flow through channels activated in a hyperpolarized state is known as:

      Your Answer:

      Correct Answer: Pace maker potential

      Explanation:

      Rhythmically discharging cells have a membrane potential that, after each impulse, declines to the firing level. Thus this prepotential or Pacemaker potential triggers the next impulse. The inherent leakiness of the sinus nodal fibers to Na+ and Ca2+ causes their self excitation.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 3 - Which of the following is first to rise following myocardial infarction? ...

    Incorrect

    • Which of the following is first to rise following myocardial infarction?

      Your Answer:

      Correct Answer: Myoglobin

      Explanation:

      Myoglobin, is a sensitive indicator of muscle injury and is first to rise following MI within two hours but is nonspecific.Troponin and CK-MB both begin to rise approximately three hours after MI. The cardiac troponins T and I which are released within 4–6 hours of an attack of MI and remain elevated for up to 2 weeks, have nearly complete tissue specificity and are now the preferred markers for assessing myocardial damage.Lactate dehydrogenase (LDH) begins to rise approximately 12 hours after MI.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 4 - The approximate incidence of deep venous thrombosis (DVT) in the general population each...

    Incorrect

    • The approximate incidence of deep venous thrombosis (DVT) in the general population each year is:

      Your Answer:

      Correct Answer: 1 per 1000

      Explanation:

      About 1 in 1000 adults per year has DVT, but as of 2011, available data is dominated by North American and European populations. DVT is rare in children, with an incidence of about 1 in 100,000 a year. From childhood to old age, incidence increases by a factor of about 1000, with almost 1% of the elderly experiencing DVTs yearly.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 5 - The coronary sinus drains into the: ...

    Incorrect

    • The coronary sinus drains into the:

      Your Answer:

      Correct Answer: Right atrium

      Explanation:

      The coronary sinus drains into the right atrium. Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins. Apart from these there are other vessels that drain directly into the heart chambers.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 6 - Where does the SA node develop? ...

    Incorrect

    • Where does the SA node develop?

      Your Answer:

      Correct Answer: From structures on the right side of the embryo.

      Explanation:

      The SA node develops from the right side of the embryo and the AV node from the left. This is the reason why in adults the right vagus supplies the SA node and the left vagus supplies the AV node.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 7 - Water hammer pulse is found in: ...

    Incorrect

    • Water hammer pulse is found in:

      Your Answer:

      Correct Answer: Aortic insufficiency

      Explanation:

      Watson’s water hammer pulse is the medical sign which describes a pulse that is bounding and forceful, rapidly increasing and subsequently collapsing, as if it were the sound of a water hammer that was causing the pulse. A water hammer was a Victorian toy in which a tube was half filled with fluid, the remainder being a vacuum. The child would invert and reinvert the tube; each time the impact of the fluid at each end would sound like a hammer blow. This is associated with increased stroke volume of the left ventricle and decrease in the peripheral resistance leading to the widened pulse pressure of aortic regurgitation.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 8 - The direct determinants of cardiac output are ...

    Incorrect

    • The direct determinants of cardiac output are

      Your Answer:

      Correct Answer: Stroke volume and heart rate

      Explanation:

      Cardiac output is classically defined alongside stroke volume (SV) and the heart rate (HR) as:Cardiac Output [L/min] = Stroke Volume [L/beat] x Heart Rate [beats/min]

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 9 - Cross-bridges between actin and myosin filaments contain: ...

    Incorrect

    • Cross-bridges between actin and myosin filaments contain:

      Your Answer:

      Correct Answer: Calcium ions

      Explanation:

      At rest troponin I is bound to actin and tropomyosin and covers the site where the myosin head interacts with actin. When calcium enters into the muscle, it binds with troponin C and causes a structural change in troponin I which moves out of the myosin binding site and causes the cross bridges between the actin and myosin filaments to occur.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 10 - How does pregnancy affect the cardiac output of a patient? ...

    Incorrect

    • How does pregnancy affect the cardiac output of a patient?

      Your Answer:

      Correct Answer: Increased cardiac output due to increase in heart rate and stroke volume

      Explanation:

      Cardiac Output increases to a similar degree as the blood volume. During the first trimester cardiac output is 30-40% higher than in the non-pregnant state. Steady rises are shown on Doppler echocardiography, from an average of 6.7 litres/minute at 8-11 weeks to about 8.7 litres/minute flow at 36-39 weeks; they are due, primarily, to an increase in stroke volume (35%) and, to a lesser extent, to a more rapid heart rate (15%). There is a steady reduction in systemic vascular resistance (SVR) which contributes towards the hyperdynamic circulation observed in pregnancy

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 11 - Closure of the tricuspid valve is marked by which of the following features...

    Incorrect

    • Closure of the tricuspid valve is marked by which of the following features of the jugular venous waveform?

      Your Answer:

      Correct Answer: c wave

      Explanation:

      The jugular venous pressure (JVP) classically has three upward deflections and two downward deflections. The upward deflections are the a (atrial contraction), c (ventricular contraction and resulting bulging of tricuspid into the right atrium during isovolumetric systole) and v = venous filling. The downward deflections of the wave are the x (the atrium relaxes and the tricuspid valve moves downward) and the y descent (filling of ventricle after tricuspid opening).

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 12 - In the cardiac cycle, all of the following are true except: ...

    Incorrect

    • In the cardiac cycle, all of the following are true except:

      Your Answer:

      Correct Answer: Mitral valve is closed by contraction of papillary muscles

      Explanation:

      Mitral valve is closed by contraction of papillary muscles: This statement is incorrect. The mitral valve closes due to the pressure difference between the left ventricle and the left atrium at the onset of ventricular systole. The papillary muscles contract to prevent prolapse of the valve into the atrium but do not cause the valve to close.

      The left ventricular volume is maximal at the end of atrial systole: This statement is true. At the end of atrial systole, the atria have pushed the remaining blood into the ventricles, making the ventricular volume maximal (end-diastolic volume).

      The left ventricular pressure is maximal just before the aortic valve opens: This statement is true. Left ventricular pressure peaks just before the aortic valve opens, as the ventricle contracts to overcome the pressure in the aorta.

      The ejection fraction is about 55%: This statement is true. The ejection fraction, which is the percentage of blood ejected from the ventricles with each contraction, is typically around 55%.

      The ‘a’ wave is due to atrial systole: This statement is true. The ‘a’ wave on the venous pressure curve corresponds to atrial systole, reflecting the increased pressure from atrial contraction.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 13 - Concerning S3, which of the following statements is INCORRECT? ...

    Incorrect

    • Concerning S3, which of the following statements is INCORRECT?

      Your Answer:

      Correct Answer: Coincide with atrial contraction

      Explanation:

      A third heart sound also called a ventricular gallop occurs at the beginning of diastole after S2 and is lower in pitch than S1 or S2 as it is not of valvular origin. The third heart sound is benign in youth, some trained athletes, and sometimes in pregnancy but if it re-emerges later in life it may signal cardiac problems, such as a failing left ventricle as in dilated congestive heart failure (CHF). S3 is thought to be caused by the oscillation of blood back and forth between the walls of the ventricles initiated by blood rushing in from the atria. The reason the third heart sound does not occur until the middle third of diastole is probably that during the early part of diastole, the ventricles are not filled sufficiently to create enough tension for reverberation. It may also be a result of tensing of the chordae tendineae during rapid filling and expansion of the ventricle. In other words, an S3 heart sound indicates increased volume of blood within the ventricle. An S3 heart sound is best heard with the bell-side of the stethoscope (used for lower frequency sounds). A left-sided S3 is best heard in the left lateral decubitus position and at the apex of the heart, which is normally located in the 5th left intercostal space at the midclavicular line. A right-sided S3 is best heard at the lower-left sternal border. The way to distinguish between a left and right-sided S3 is to observe whether it increases in intensity with inhalation or exhalation. A right-sided S3 will increase on inhalation, while a left-sided S3 will increase on exhalation.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 14 - Which one of the following is a cause of a soft second heart...

    Incorrect

    • Which one of the following is a cause of a soft second heart sound?

      Your Answer:

      Correct Answer: Aortic stenosis

      Explanation:

      Second heart sound (S2) forms the dub of lub-dub and is composed of components A2 and P2. •    loud: hypertension•    soft: AS•    fixed split: physiological split (normally occurs during inhalation), right bundle branch block, pulmonary stenosis, and atrial septal defect.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 15 - Generalized vasoconstrictors include: ...

    Incorrect

    • Generalized vasoconstrictors include:

      Your Answer:

      Correct Answer: Norepinephrine, endothelin, angiotensin ii

      Explanation:

      Vasopressin, angiotensin II, adrenaline and endothelin are generalized vasoconstrictors.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 16 - Coronary blood flow occurs in? ...

    Incorrect

    • Coronary blood flow occurs in?

      Your Answer:

      Correct Answer: Diastole

      Explanation:

      Coronary arteries are unique in that they fill during diastole, when not occluded by valve cusps nor compressed by myocardial contraction).

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 17 - Which of the atrial pressure changes represents the a-wave of the JVP ...

    Incorrect

    • Which of the atrial pressure changes represents the a-wave of the JVP

      Your Answer:

      Correct Answer: Atrial systole

      Explanation:

      The a-wave created on the venous pulse curve occurs as a result of atrial systole. Due to the pressure build-up in the atria, it causes a back pressure in the vena cava. This pressure is exerted on the valve and this back pressure is what causes a slight increase in the venous pressure.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 18 - Absolute refractory period in a cardiac action potential graph occurs during. ...

    Incorrect

    • Absolute refractory period in a cardiac action potential graph occurs during.

      Your Answer:

      Correct Answer: All of the above

      Explanation:

      Absolute refractory period (ARP): the cell is completely unexcitable to a new stimulus and occurs from phase 0 – 2 i.e. depolarisation, early repolarisation and plateau phase.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 19 - Vasodilatation in skeletal muscle can be caused by: ...

    Incorrect

    • Vasodilatation in skeletal muscle can be caused by:

      Your Answer:

      Correct Answer: Sympathetic cholinergic nerves

      Explanation:

      In skeletal muscles some fibers that cause vasodilation run with the nerves of the sympathetic system but are cholinergic in nature. These nerves are not active during rest but become active during exercise and stress.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 20 - What is cardiac output? ...

    Incorrect

    • What is cardiac output?

      Your Answer:

      Correct Answer: Product of stroke volume and heart rate

      Explanation:

      Cardiac output is the product of stroke volume and heart rate.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 21 - Coronary arteries arise from? ...

    Incorrect

    • Coronary arteries arise from?

      Your Answer:

      Correct Answer: None of the above

      Explanation:

      Coronary arteries arise from the sinuses behind 2 of the cusps of the aortic valve at the root of aorta.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 22 - In the Fick‘s method of measuring cardiac output, the arterial oxygen content can...

    Incorrect

    • In the Fick‘s method of measuring cardiac output, the arterial oxygen content can be measured in a sample obtained from

      Your Answer:

      Correct Answer: The pulmonary vein

      Explanation:

      In Fick’s original method, the following variables are measured:VO2, oxygen consumption in ml of pure gaseous oxygen per minute. This may be measured using a spirometer within a closed rebreathing circuit incorporating a CO2 absorberCa, the oxygen concentration of blood taken from the pulmonary vein (representing oxygenated blood)Cv, the oxygen concentration of blood from an intravenous cannula (representing deoxygenated blood)From these values, we know that:VO2 = (CO x Ca) – (CO x Cv)where CO = Cardiac Output, Ca = Oxygen concentration of arterial blood and Cv = Oxygen concentration of mixed venous blood.This allows us to sayCO = VO2/{Ca – Cv}and hence calculate cardiac output.Note that (Ca – Cv) is also known as the arteriovenous oxygen difference.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 23 - Which of the following conditions does not influence the cardiac output? ...

    Incorrect

    • Which of the following conditions does not influence the cardiac output?

      Your Answer:

      Correct Answer: Sleep

      Explanation:

      Sleep has no effect on the cardiac output.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 24 - Which vaso metabolite decreases coronary blood flow? ...

    Incorrect

    • Which vaso metabolite decreases coronary blood flow?

      Your Answer:

      Correct Answer: Endothelin

      Explanation:

      Decreased O2, increased CO2, lactate, prostaglandins, adenine nucleotides, adenosine, H+, K+ and cyanide produce vasodilation and thus an increase in coronary blood flow.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 25 - Which is the most common site for primary cardiac tumours to occur in...

    Incorrect

    • Which is the most common site for primary cardiac tumours to occur in adults?

      Your Answer:

      Correct Answer: Left atrium

      Explanation:

      Myxomas are the most common type of primary heart tumour. The tumour is derived from multipotential mesenchymal cells and may cause a ball valve-type obstruction. About 75% of myxomas occur in the left atrium of the heart, usually beginning in the wall that divides the two upper chambers of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 26 - Factors influencing cardiac output include which of the following? ...

    Incorrect

    • Factors influencing cardiac output include which of the following?

      Your Answer:

      Correct Answer: All of the above

      Explanation:

      There is a correlation between resting CO and body surface area. The output per min per square meter of body surface (the cardiac index) averages 3.2l.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 27 - In which area is depolarization initiated? ...

    Incorrect

    • In which area is depolarization initiated?

      Your Answer:

      Correct Answer: SA node

      Explanation:

      SA node is the pacemaker of the heart. It determines the rate of contractions. It is the place where depolarization is initiated. It exhibits phase 4 depolarization or automaticity. Electrical impulses then spread to the AV node, purkinje fibers, bundle of his and the ventricular muscles.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 28 - Regarding the length of systole and diastole which of the following is true?...

    Incorrect

    • Regarding the length of systole and diastole which of the following is true?

      Your Answer:

      Correct Answer: The duration of systole is more fixed than diastole

      Explanation:

      The duration of systole is more fixed than the duration of diastole. When the heart rate increases the timing of systole remains more or less the same however, diastole decreases.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 29 - In which organ will you find extremely porous sinusoidal capillaries, with discontinuous endothelium?...

    Incorrect

    • In which organ will you find extremely porous sinusoidal capillaries, with discontinuous endothelium?

      Your Answer:

      Correct Answer: Liver

      Explanation:

      The liver is the organ which contains sinusoidal capillaries with discontinuous endothelium. The brain, lungs and the intestine all contain continuous capillaries, however the kidney contains fenestrated capillaries to aid in filtration.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 30 - The function of ATP in cardiac muscle contraction includes: ...

    Incorrect

    • The function of ATP in cardiac muscle contraction includes:

      Your Answer:

      Correct Answer: Binding to myosin after the power stroke to allow uncoupling of actin and myosin

      Explanation:

      After calcium binds to the troponin C, there is a conformational change in the structure of troponin I and tropomyosin, which moves out of the way and frees the site where myosin can bind to actin. This results in the formation of the cross linkage of the actin and myosin giving rise to the power stroke in the contraction phase. This occurs with the release of ADP. When ATP combines to this complex it breaks and the cycle repeats itself.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 31 - Which of the following structures is not part of the conducting system of...

    Incorrect

    • Which of the following structures is not part of the conducting system of the heart?

      Your Answer:

      Correct Answer: Ventricular wall

      Explanation:

      The conduction system of the heart consists of the SA node, AV node, internodal pathway between these two nodes, Bundle of His and the purkinje fibers

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 32 - Which of the following statements is true regarding pulsus alternans? ...

    Incorrect

    • Which of the following statements is true regarding pulsus alternans?

      Your Answer:

      Correct Answer: It is found in association with a third heart sound

      Explanation:

      Pulsus alternans is a physical finding with arterial pulse waveform showing alternating strong and weak beats. It is almost always indicative of left ventricular systolic impairment, and carries a poor prognosis. A pathological third heart sound is usually associated.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 33 - Which of the following corresponds to an oblique line drawn from the sternal...

    Incorrect

    • Which of the following corresponds to an oblique line drawn from the sternal end of the left 3rd costal cartilage to the sternal end of the right 6th costal cartilage?

      Your Answer:

      Correct Answer: Atrio-ventricular (coronary) groove

      Explanation:

      The AV groove corresponds to the right border of the heart. The right border corresponds to a line drawn from the 3rd right costal cartilage to the 6th right costal cartilage; this border is slightly convex to the right.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 34 - During exercise, a man consumes 2L O2/min, his arterial 02 content is 190...

    Incorrect

    • During exercise, a man consumes 2L O2/min, his arterial 02 content is 190 ml/l and the 02 content of his mixed venous blood is 130ml/l. His cardiac output is approximately:

      Your Answer:

      Correct Answer: 33l/min

      Explanation:

      In Fick’s original method, the following variables are measured:VO2, oxygen consumption in ml of pure gaseous oxygen per minute. This may be measured using a spirometer within a closed rebreathing circuit incorporating a CO2 absorberCa, the oxygen concentration of blood taken from the pulmonary vein (representing oxygenated blood)Cv, the oxygen concentration of blood from an intravenous cannula (representing deoxygenated blood)From these values, we know that:VO2 = (CO x Ca) – (CO x Cv)where CO = Cardiac Output, Ca = Oxygen concentration of arterial blood and Cv = Oxygen concentration of mixed venous blood.This allows us to sayCO = VO2/{Ca – Cv}and hence calculate cardiac output.Therefore CO = 2/(0.190-0.130) = 33l/minNote that (Ca – Cv) is also known as the arteriovenous oxygen difference.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 35 - Sinus bradycardia may be caused by disease of which of the following: ...

    Incorrect

    • Sinus bradycardia may be caused by disease of which of the following:

      Your Answer:

      Correct Answer: Right coronary artery

      Explanation:

      Disease of the right coronary artery may cause sinus bradycardia and AV nodal block.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 36 - What is the effect of catecholamines (i.e. increased heart rate) on the pressure...

    Incorrect

    • What is the effect of catecholamines (i.e. increased heart rate) on the pressure volume loop?

      Your Answer:

      Correct Answer: Shifts the diastolic pressure curve upward and leftward

      Explanation:

      Catecholamines have a positive ionotropic and chronotropic effect on the heart. The ventricles develop greater tension during systole resulting in an increase in the stroke volume. The increase in stroke volume results in a decrease in the end diastolic volume. This pushes the loop towards the left and upwards.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 37 - What is pulse pressure? ...

    Incorrect

    • What is pulse pressure?

      Your Answer:

      Correct Answer: Difference between systolic and diastolic pressure

      Explanation:

      The pulse pressure is the difference between the measured systolic and diastolic pressures.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 38 - All of the following are consistent with the indicator dilution method except--- ...

    Incorrect

    • All of the following are consistent with the indicator dilution method except---

      Your Answer:

      Correct Answer: In thermodilution, the indicator used is warm saline

      Explanation:

      In thermodilution, the indicator used is cold saline.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 39 - The heart rate can be accelerated by: ...

    Incorrect

    • The heart rate can be accelerated by:

      Your Answer:

      Correct Answer: Exercise and thyroid hormones

      Explanation:

      The firing of the SA node will increase due to exercises and as the thyroid hormone has a chronotropic effect on the heart, it too will result in an increase in the heart rate via stimulation of the adrenergic receptors of the heart. As during exercise the sympathetic nervous system is activated, it will directly have an positive chronotropic effect on the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 40 - Why does arterial blood pressure drop during pregnancy? ...

    Incorrect

    • Why does arterial blood pressure drop during pregnancy?

      Your Answer:

      Correct Answer: Progesterone relaxes vascular smooth muscle

      Explanation:

      Progesterone relaxes vascular smooth muscle thus resulting In a decrease in total peripheral resistance. This accounts for the increase in the cardiac output.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 41 - Which statement about the 2nd heart sound is true? ...

    Incorrect

    • Which statement about the 2nd heart sound is true?

      Your Answer:

      Correct Answer: It is caused by closure of the aortic and pulmonary valves.

      Explanation:

      The second heart sound is produced due to closure of the aortic and pulmonary valves. It is a high pitched dub sound.

      Normally the aortic closure sound (A2) occurs prior to the pulmonic closure sound (P2), and the interval between the two (splitting) widens on inspiration and narrows on expiration. With quiet respiration, A2 will normally precede P2 by 0.02 to 0.08 second (mean, 0.03 to 0.04 sec) with inspiration. In younger subjects inspiratory splitting averages 0.04 to 0.05 second during quiet respiration. With expiration, A2 and P2 may be superimposed and are rarely split as much as 0.04 second. If the second sound is split by greater than 0.04 second on expiration, it is usually abnormal. Therefore, the presence of audible splitting during expiration (i.e., the ability to hear two distinct sounds during expiration) is of greater significance at the bedside in identifying underlying cardiac pathology than is the absolute inspiratory increase in the A2–P2 interval.

      The respiratory variation of the second heart sound can be categorized as follows: (1) normal (physiologic) splitting; (2) persistent (audible expiratory) splitting, with normal respiratory variation; (3) persistent splitting without respiratory variation (fixed splitting); and (4) reversed (paradoxical) splitting.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 42 - Concerning surface anatomy, where is the base of the heart ...

    Incorrect

    • Concerning surface anatomy, where is the base of the heart

      Your Answer:

      Correct Answer: 2nd left costal to 3rd right costal cartilage

      Explanation:

      The base of the heart, also known as the superior border of the heart corresponds to a line connecting the inferior border of the 2nd left costal cartilage to the superior border of the 3rd right costal cartilage.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 43 - Which of the following would be a contraindication to thrombolysis? ...

    Incorrect

    • Which of the following would be a contraindication to thrombolysis?

      Your Answer:

      Correct Answer: Intracranial neoplasm

      Explanation:

      Absolute contraindications to thrombolysis include:

      • Previous intracranial bleeding at any time
      • Stroke in less than 6 months
      • Closed head or facial trauma within 3 months
      • Suspected aortic dissection
      • Ischemic stroke within 3 months (except in ischemic stroke within 3 hours time)
      • Active bleeding diathesis
      • Uncontrolled high blood pressure (>180 systolic or >100 diastolic)
      • Known structural cerebral vascular lesion
      • Arterio-venous malformations
      • Thrombocytopenia
      • Known coagulation disorders
      • Aneurysm
      • Brain tumours
      • Pericardial effusion
      • Septic embolus

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 44 - Which of the following is true with AV nodal delay? ...

    Incorrect

    • Which of the following is true with AV nodal delay?

      Your Answer:

      Correct Answer: Shortened by sympathetic stimulation

      Explanation:

      AV nodal delay Is about 0.1s before the action potential spreads to the ventricles. It is shortened by stimulation of the sympathetic nervous system and lengthened by stimulation of the parasympathetic system.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 45 - When the heart rate is increased (to pathological levels) which of the following...

    Incorrect

    • When the heart rate is increased (to pathological levels) which of the following is correct when comparing the duration of diastole to systole?

      Your Answer:

      Correct Answer: It is shortened to a greater degree

      Explanation:

      The duration of systole is more fixed than the duration of diastole. When the heart rate increases the timing of the systole remains more or less the same however diastole decreases.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 46 - Angina pectoris develops when blood through the coronary artery becomes: ...

    Incorrect

    • Angina pectoris develops when blood through the coronary artery becomes:

      Your Answer:

      Correct Answer: Restricted, limiting blood blow

      Explanation:

      Angina pectoris develops when stenosis ( >70%) of the artery occurs as a result of formation of an atherosclerotic plaque. This leads to a decrease in the O2 carried to the thickened heart muscle by the blood, leading to the characteristic chest pain associated with angina pectoris.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 47 - Which coronary artery supplies the right atria? ...

    Incorrect

    • Which coronary artery supplies the right atria?

      Your Answer:

      Correct Answer: Right coronary

      Explanation:

      The left coronary artery distributes blood to the left side of the heart, the left atrium and ventricle, and the interventricular septum. The circumflex artery arises from the left coronary artery and follows the coronary sulcus to the left. Eventually, it will fuse with the small branches of the right coronary artery. The right coronary artery proceeds along the coronary sulcus and distributes blood to the right atrium, portions of both ventricles, and the heart conduction system.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 48 - The bradycardia that occurs in patients with raised intracranial pressure is a result...

    Incorrect

    • The bradycardia that occurs in patients with raised intracranial pressure is a result of the?

      Your Answer:

      Correct Answer: Cushing reflex

      Explanation:

      When intracranial pressure is increased, the blood supply to RVLM neurons is compromised. This results in an increase in their discharge as a result of hypoxia and hypercapnia. The resultant rise in systemic arterial pressure (Cushing reflex) tends to restore the blood flow to the medulla.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 49 - Select the correct statement regarding the 4th heart sound, it? ...

    Incorrect

    • Select the correct statement regarding the 4th heart sound, it?

      Your Answer:

      Correct Answer: Can be heard in atrial systole.

      Explanation:

      The fourth heart sound is not normally audible in a normal adult. It occurs as a consequence of ventricular hypertrophy. It is caused by filling of the ventricle by atrial systole.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 50 - Which one of the following is a risk factor for torsade de pointes?...

    Incorrect

    • Which one of the following is a risk factor for torsade de pointes?

      Your Answer:

      Correct Answer: Hypothermia

      Explanation:

      The following is a list of factors associated with an increased tendency toward torsades de pointes:- Hypokalaemia (low blood potassium)- Hypomagnesemia (low blood magnesium)- Hypocalcaemia (low blood calcium)- Bradycardia (slow heartbeat)- Heart failure- Left ventricular hypertrophy- Hypothermia- Subarachnoid haemorrhage- Hypothyroidism

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 51 - Which of the following conditions has no effect on cardiac output? ...

    Incorrect

    • Which of the following conditions has no effect on cardiac output?

      Your Answer:

      Correct Answer: Sleep

      Explanation:

      Sleep has no effect on the cardiac output. Anxiety, excitement and pregnancy will increase the cardiac output. Standing from a lying position will decrease the cardiac output transiently.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 52 - What is a characteristic findings on ECG in hyperkalaemia? ...

    Incorrect

    • What is a characteristic findings on ECG in hyperkalaemia?

      Your Answer:

      Correct Answer: Tall, tented T waves

      Explanation:

      Hyperkalaemia leads to:

      – Prolonged PR interval

      – Small P waves

      – Tall, tented T waves

      – Widened QRS complexes and eventually asystole.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 53 - What is the main reason for checking the urea and electrolytes prior to...

    Incorrect

    • What is the main reason for checking the urea and electrolytes prior to commencing a patient on amiodarone?

      Your Answer:

      Correct Answer: To detect hypokalaemia

      Explanation:

      All antiarrhythmic drugs have the potential to cause arrhythmias. Coexistent hypokalaemia significantly increases this risk.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 54 - The Plateau phase in myocyte action potentials does all of the following except:...

    Incorrect

    • The Plateau phase in myocyte action potentials does all of the following except:

      Your Answer:

      Correct Answer: It allows early reactivation of the myocytes

      Explanation:

      The presence of the plateau in the action potential causes ventricular contraction to last as much as 15 times longer in cardiac muscle as in skeletal muscle. The plateau phase which follows is unique to myocytes and results from a small, but sustained inward calcium current through L-type calcium channels lasting 200-400 ms. This calcium influx is caused by a combined increase in permeability of the cell and especially the sarcolemmal membranes to calcium. This plateau (refractory) phase prevents early reactivation of the myocytes and directly determines the strength of contraction.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 55 - The Sinoatrial node in the majority of people is supplied by the? ...

    Incorrect

    • The Sinoatrial node in the majority of people is supplied by the?

      Your Answer:

      Correct Answer: Right coronary artery

      Explanation:

      In 60% of people, the SA node is supplied by the right coronary artery branch and in 40% of the people by the left coronary artery.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 56 - The principle by which the energy of contraction is proportional to the initial...

    Incorrect

    • The principle by which the energy of contraction is proportional to the initial length of cardiac muscle fiber is known as:

      Your Answer:

      Correct Answer: Starling’s law

      Explanation:

      The Frank starling relationship describes that an increase in the venous return or the end diastolic volume will cause an increase in the stroke volume/ preload and also cardiac output. It stems from the fact that increase venous return will increase the stretch on the ventricular muscle fibers. The sarcomere will stretch a considerable length that is needed for maximum contraction and increased development of tension in the muscle fiber. The greater the venous return the greater the cardiac output. This relation is directly proportional.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 57 - Regarding the cardiac muscle striations as viewed under the microscope, which areas are...

    Incorrect

    • Regarding the cardiac muscle striations as viewed under the microscope, which areas are dark?

      Your Answer:

      Correct Answer: A band and z line

      Explanation:

      Dark bands: a, h. Dark line: z. Clear band: i, m

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 58 - Excitation-contraction coupling in cardiac muscle involves all of the following except: ...

    Incorrect

    • Excitation-contraction coupling in cardiac muscle involves all of the following except:

      Your Answer:

      Correct Answer: Binding of Ca2+ to calmodulin

      Explanation:

      In the excitation contraction coupling model, an action potential is transmitted to the fibrils of a fiber through the T tubule system. It triggers the release of Ca 2+ from the terminal cisterns. Depolarization of the T tubules activates the sarcoplasmic reticulum through the dihydropyridine receptors. These are voltage gates calcium channels. Calcium binds to calmodulin during contraction of the smooth muscle and not the cardiac muscles.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 59 - The amount of a substance taken up by an organ (or whole body)...

    Incorrect

    • The amount of a substance taken up by an organ (or whole body) per unit time is = (the arterial level - the venous level) * the blood flow. This statement describes?

      Your Answer:

      Correct Answer: The Fick principle

      Explanation:

      The essence of the Fick principle is that blood flow to an organ can be calculated using a marker substance if the following information is known:- Amount of marker substance taken up by the organ per unit time- Concentration of marker substance in arterial blood supplying the organ- Concentration of marker substance in venous blood leaving the organ

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 60 - If both the noradrenergic and the cholinergic systems are blocked in the heart,...

    Incorrect

    • If both the noradrenergic and the cholinergic systems are blocked in the heart, the rate will be approximately:

      Your Answer:

      Correct Answer: 100/min

      Explanation:

      The normal heart beat is about 70/min. This is due to a predominant parasympathetic activity. If sympathetic activity was unopposed the heart rate would have been 150/min. When both the noradrenergic and cholinergic systems are blocked the heart rate is 100/min. This is the normal firing rate of the SA node.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 61 - The coronary arteries fill during? ...

    Incorrect

    • The coronary arteries fill during?

      Your Answer:

      Correct Answer: Diastole

      Explanation:

      During systole the coronary arteries collapse as a result of the pressure due to contraction that is exerted on them. During diastole the heart muscle relaxes and the pressure on the coronary vessels is relieved allowing blood to flow through them to the subendocardium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 62 - The right border of the heart corresponds to which line on the surface...

    Incorrect

    • The right border of the heart corresponds to which line on the surface of the chest?

      Your Answer:

      Correct Answer: Line drawn from the 3rd right costal cartilage to the 6th right costal cartilage

      Explanation:

      The right border corresponds to a line drawn from the 3rd right costal cartilage to the 6th right costal cartilage; this border is slightly convex to the right.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 63 - What type of intercellular connection found between cardiac muscle fibers allow for the...

    Incorrect

    • What type of intercellular connection found between cardiac muscle fibers allow for the spread of excitation from one cell to another?

      Your Answer:

      Correct Answer: Gap junctions

      Explanation:

      The cardiac muscles have gap junctions in-between the cells. They form low resistance passages, which allow ions to diffuse through every muscle fiber rapidly and result in the cardiac muscles functioning as a syncytium, without any protoplasmic bridges involved.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 64 - Which of the following makes up the thick filaments in muscle fibers? ...

    Incorrect

    • Which of the following makes up the thick filaments in muscle fibers?

      Your Answer:

      Correct Answer: Myosin

      Explanation:

      The thick filaments are made up of myosin and the thin filaments are made up of actin. The thick filaments are twice the size of the thin filaments and are aligned to form the A band. The thin filaments extending out from the A band form the less dense I bands.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 65 - The coronary arteries supply which part of the heart’s subendocardial region exclusively in...

    Incorrect

    • The coronary arteries supply which part of the heart’s subendocardial region exclusively in diastole?

      Your Answer:

      Correct Answer: Left ventricle

      Explanation:

      It is only during diastole that the blood flows to the subendocardial portion of the left ventricle, as the heart muscle relaxes and the coronary arteries regain their patency.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 66 - Coronary arteries fill up during ...

    Incorrect

    • Coronary arteries fill up during

      Your Answer:

      Correct Answer: Diastole

      Explanation:

      During contraction of the ventricular myocardium (systole), the subendocardial coronary vessels (the vessels that enter the myocardium) are compressed due to the high ventricular pressures. This compression results in momentary retrograde blood flow (i.e., blood flows backward toward the aorta) which further inhibits perfusion of myocardium during systole. However, the epicardial coronary vessels (the vessels that run along the outer surface of the heart) remain open. Because of this, blood flow in the sub endocardium stops during ventricular contraction. As a result, most myocardial perfusion occurs during heart relaxation (diastole) when the subendocardial coronary vessels are open and under lower pressure.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 67 - The a-wave is created by: ...

    Incorrect

    • The a-wave is created by:

      Your Answer:

      Correct Answer: Regurgitation of some blood to the great veins when the atria contracts in atrial systole

      Explanation:

      The a-wave created on the venous pulse curve occurs as a result of atrial systole. Due to the pressure build-up in the atria, it causes a back pressure in the vena cava. This pressure is exerted on the valve and this back pressure is what causes a slight increase in the venous pressure.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 68 - The triangle with the heart at its centre, using limb leads is called:...

    Incorrect

    • The triangle with the heart at its centre, using limb leads is called:

      Your Answer:

      Correct Answer: Einthoven

      Explanation:

      The Einthoven triangle is formed by placing the limb leads on both the arms and on the left leg with the heart in the centre.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 69 - In cardiac muscle, which of the following is directly responsible for the release...

    Incorrect

    • In cardiac muscle, which of the following is directly responsible for the release of Ca2+ stored in the sarcoplasmic reticulum (calcium-induced calcium release)?

      Your Answer:

      Correct Answer: Ryanodine receptor (RyR)

      Explanation:

      Ryanodine receptor (RyR) is a ligand-gated Ca2+ channel with Ca2+ as its natural ligand. In skeletal muscle, Ca2+ entry from ECF by this route is not required for Ca2+ release. Instead, the DHPR that serves as the voltage sensor unlocks release of Ca2+ from the nearby SR via physical interaction with the RyR. The release is amplified through ca-induced ca release. However, in cardiac muscle, it is the influx of extracellular Ca2+ through the voltage-sensitive DHPR in the T system that triggers ca-induced ca release trough the RyR at the SR.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 70 - Regarding the surface anatomy of the orifices of the heart, where is the...

    Incorrect

    • Regarding the surface anatomy of the orifices of the heart, where is the aortic valve located?

      Your Answer:

      Correct Answer: Opposite the left 3rd intercostal space to the left of the sternum

      Explanation:

      The aortic valve is situated in the left 3rd intercostal space just beneath the sternum.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 71 - The V wave in the jugular pulse is caused by: ...

    Incorrect

    • The V wave in the jugular pulse is caused by:

      Your Answer:

      Correct Answer: Atrial filling

      Explanation:

      The v wave reflects the passive increase in pressure and volume of the right atrium as it fills in late systole and early diastole.

      The jugular vein pulsations usually have two elevations and two troughs. The first elevation (a wave) corresponds to the slight rise in atrial pressure resulting from atrial contraction. The first descent (x descent) reflects a fall in atrial pressure that starts with atrial relaxation. The second elevation (v wave) corresponds to ventricular systole when blood is entering the right atrium from the vena cavae while the tricuspid valve is closed. Finally, the second descent (y descent) reflects falling right atrial pressure as the tricuspid valve opens and blood drains from the atrium into the ventricle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 72 - Concerning coronary arteries, what is the net effect of B2 stimulation on the...

    Incorrect

    • Concerning coronary arteries, what is the net effect of B2 stimulation on the heart (e.g. Running athlete)?

      Your Answer:

      Correct Answer: Vasodilation via production of metabolites

      Explanation:

      The coronary arterioles contain α-adrenergic receptors, which cause vasoconstriction, and β-adrenergic receptors, which cause vasodilation. Activity in the noradrenergic nerves to the heart and injections of norepinephrine cause coronary vasodilation. However, norepinephrine also increases the heart rate and the force of cardiac contraction, and the vasodilation is due to production of vasodilator metabolites in the myocardium secondary to the increase in its activity. As exercise has the same effect as sympathetic stimulation, it will result in vasodilation.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 73 - The average end diastolic volume in a healthy individual’s ventricle is? ...

    Incorrect

    • The average end diastolic volume in a healthy individual’s ventricle is?

      Your Answer:

      Correct Answer: 130 ml

      Explanation:

      The end diastolic volume in a healthy individual is about 130 ml.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 74 - Which of the following does not lower ventricular rate in atrial fibrillation? ...

    Incorrect

    • Which of the following does not lower ventricular rate in atrial fibrillation?

      Your Answer:

      Correct Answer: Adrenaline

      Explanation:

      Adrenaline is a sympathetic neurotransmitter which increases the heart rate. During atrial fibrillation the atria is contracting at more than 200 beats/min. Acetylcholine is a parasympathetic neurotransmitter decreasing the heart rate. Digital also depresses the conduction at the AV conduction. Vagal discharge and occulocardiac reflux decrease the heart rate and convert the tachycardia into normal sinus rhythm.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 75 - Although variable, branches of which artery most often supply the SA and AV...

    Incorrect

    • Although variable, branches of which artery most often supply the SA and AV nodes?

      Your Answer:

      Correct Answer: Right coronary artery

      Explanation:

      The RCA (right coronary artery) supplies the SA and the AV nodes along with the postero-basal wall of the left ventricle, posterior one third of the inferior vena cava, right ventricle and the posteromedial papillary muscle in the left ventricle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 76 - The most resistant area in the brain to hypoxia is: ...

    Incorrect

    • The most resistant area in the brain to hypoxia is:

      Your Answer:

      Correct Answer: Brain stem

      Explanation:

      The structures in the brainstem are more resistant to hypoxia than the cerebral cortex and the rest of the brain structures.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 77 - Digoxin causes: ...

    Incorrect

    • Digoxin causes:

      Your Answer:

      Correct Answer: Increase in cytosolic calcium concentration

      Explanation:

      Digoxin is a positive inotrope which inhibits NA/K ATPase, increases cardiac contractility and can cause hypokalaemia.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 78 - The rate of depolarisation of the sinus node membrane potential is modulated by...

    Incorrect

    • The rate of depolarisation of the sinus node membrane potential is modulated by all the following except:

      Your Answer:

      Correct Answer: Cardiac output

      Explanation:

      Cardiac output has no effect on the depolarization of the pacemaker potential of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 79 - Which of the following intercellular connections is important in endothelial barrier function? ...

    Incorrect

    • Which of the following intercellular connections is important in endothelial barrier function?

      Your Answer:

      Correct Answer: Tight junctions

      Explanation:

      Tight junctions surround the apical margins of the epithelial cells such as in the intestinal mucosa and the choroid plexus. They are also important to the endothelial barrier function. They are made up of ridges that adhere to each other strongly at the cell junction, obliterating the space completely between the cells.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 80 - Afferent fibers from the baroreceptors of the great arteries form branches of which...

    Incorrect

    • Afferent fibers from the baroreceptors of the great arteries form branches of which cranial nerves?

      Your Answer:

      Correct Answer: Glossopharyngeal and vagus nerves

      Explanation:

      The receptors of the carotid sinus are innervated by the carotid sinus nerve, a branch of the glossopharyngeal nerve. The aortic arch receptors located in the arch of the aorta are innervated by the aortic depressor nerve, a branch of the vagus nerve.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 81 - Which heart sounds are matched correctly? ...

    Incorrect

    • Which heart sounds are matched correctly?

      Your Answer:

      Correct Answer: All of the above

      Explanation:

      In healthy adults, there are two normal heart sounds often described as a lub and a dub (or dup), that occur in sequence with each heartbeat. These are the first heart sound (S1) and second heart sound (S2), produced by the closing of the atrioventricular valves and semilunar valves, respectively. In addition to these normal sounds, a variety of other sounds may be present including heart murmurs, adventitious sounds, and gallop rhythms S3 and S4. S3 is thought to be caused by the oscillation of blood back and forth between the walls of the ventricles initiated by blood rushing in from the atria. The reason the third heart sound does not occur until the middle third of diastole is probably that during the early part of diastole, the ventricles are not filled sufficiently to create enough tension for reverberation. S4 when audible in an adult is called a presystolic gallop or atrial gallop. This gallop is produced by the sound of blood being forced into a stiff or hypertrophic ventricle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 82 - The rate of depolarization of the SA node membrane potential is modulated by...

    Incorrect

    • The rate of depolarization of the SA node membrane potential is modulated by the following:

      Your Answer:

      Correct Answer: All of the above

      Explanation:

      Rate of depolarization of the SA node is modulated by all of these.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 83 - Which of the following antiarrhythmic drugs may be used in the treatment of...

    Incorrect

    • Which of the following antiarrhythmic drugs may be used in the treatment of long QT syndrome?

      Your Answer:

      Correct Answer: Atenolol

      Explanation:

      Beta-blockers are the mainstay of treatment in long QT syndrome. Implantable cardioverter-defibrillators are the most effective treatment in genotypes with a high risk of recurrence.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 84 - Normal stroke volume is about: ...

    Incorrect

    • Normal stroke volume is about:

      Your Answer:

      Correct Answer: 70 ml

      Explanation:

      Stroke volume is the amount of blood that is pumped from the heart into the aorta. It is typically 70 ml.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 85 - Which factors increase the end-diastolic volume? ...

    Incorrect

    • Which factors increase the end-diastolic volume?

      Your Answer:

      Correct Answer: Constriction of veins

      Explanation:

      End diastolic volume is also known as preload. It is the amount of blood the heart contracts against. Constriction of veins will decrease venous pooling and increase venous return, hence increasing the end diastolic volume. Standing will increase venous pooling hence decreasing venous return and end diastolic volume. Raised intrapericardial pressure will also decrease venous return and hence end diastolic volume.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 86 - What are the diagnostic criteria for an ST segment elevation type of acute...

    Incorrect

    • What are the diagnostic criteria for an ST segment elevation type of acute myocardial infarction?

      Your Answer:

      Correct Answer: 1 mm ST elevation in 2 limb leads

      Explanation:

      The current guidelines for the ECG diagnosis of the ST segment elevation type of acute myocardial infarction require at least 1 mm (0.1 mV) of ST segment elevation in the limb leads, and at least 2 mm elevation in the precordial leads. These elevations must be present in anatomically contiguous leads. (I, aVL, V5, V6 correspond to the lateral wall; V3-V4 correspond to the anterior wall ; V1-V2 correspond to the septal wall; II, III, aVF correspond to the inferior wall.)

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 87 - The major factor in controlling coronary artery blood flow is considered to be?...

    Incorrect

    • The major factor in controlling coronary artery blood flow is considered to be?

      Your Answer:

      Correct Answer: Metabolites of oxygen consumption

      Explanation:

      There is a strong relationship between myocardial blood flow and oxygen consumption. This indicates that products of metabolism may cause vasodilation of the coronary artery.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 88 - Myocardial fibers have a resting membrane potential of approximately: ...

    Incorrect

    • Myocardial fibers have a resting membrane potential of approximately:

      Your Answer:

      Correct Answer: -90mv

      Explanation:

      The resting membrane potential of the mammalian heart is about -90 mv.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 89 - The internodal tract of Bachman: ...

    Incorrect

    • The internodal tract of Bachman:

      Your Answer:

      Correct Answer: Connects the SA node to the AV node

      Explanation:

      Internodal tract of Bachman connects the SA node to the AV node conducting the electrical impulses generated from the SA node to the AV node and from the AV node to the rest of the electrical complex of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 90 - Which of the following occurs during a Valsalva manoeuvre? ...

    Incorrect

    • Which of the following occurs during a Valsalva manoeuvre?

      Your Answer:

      Correct Answer: An initial rise in blood pressure

      Explanation:

      The Valsalva maneuver involves forced expiration against a closed glottis. It has several phases, each affecting the cardiovascular system differently:

      1. Phase I: During the initial forced expiration against the closed glottis, there is a transient rise in intrathoracic pressure, which compresses the thoracic aorta and causes a brief increase in blood pressure.
      2. Phase II: Continued straining leads to decreased venous return to the heart, reducing cardiac output and causing a drop in blood pressure. This phase is characterized by a compensatory increase in heart rate.
      3. Phase III: Upon releasing the strain, there is a sudden drop in intrathoracic pressure, which momentarily decreases blood pressure.
      4. Phase IV: Blood pressure then rises rapidly as venous return to the heart is restored, leading to increased cardiac output. This is often followed by a reflex bradycardia (slow heart rate).

      Given these phases, the most accurate statement about what occurs during the Valsalva maneuver is the initial rise in blood pressure (Phase I).

      Other options explained:

      • Forced inspiration against a closed glottis: Incorrect. The Valsalva maneuver involves forced expiration, not inspiration, against a closed glottis.
      • Low intrathoracic pressures throughout: Incorrect. The Valsalva maneuver involves high intrathoracic pressures due to forced expiration.
      • Disruption of autonomic function: Incorrect. The Valsalva maneuver affects autonomic function but does not disrupt it. Instead, it triggers autonomic responses to changes in blood pressure and heart rate.
      • No change: Incorrect. The Valsalva maneuver causes significant changes in blood pressure and heart rate.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 91 - Myocardial oxygen consumption is increased by: ...

    Incorrect

    • Myocardial oxygen consumption is increased by:

      Your Answer:

      Correct Answer: An increase in after load

      Explanation:

      Cardiac oxygen consumption is directly related to the amount of tension that develops in the ventricles. It is increased by an increased size of heart, increased afterload, increased contractility and increased heart rate.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 92 - What is the most common cardiac defect seen in patients with Down’s syndrome?...

    Incorrect

    • What is the most common cardiac defect seen in patients with Down’s syndrome?

      Your Answer:

      Correct Answer: Atrioventricular septal defect

      Explanation:

      The rate of congenital heart disease in new-borns with Down syndrome is around 40%. Of those with heart disease, about 80% have an atrioventricular septal defect or ventricular septal defect with the former being more common. Mitral valve problems become common as people age, even in those without heart problems at birth.[3] Other problems that may occur include tetralogy of Fallot and patent ductus arteriosus.[38] People with Down syndrome have a lower risk of hardening of the arteries

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 93 - Dicrotic notch is produced by which valves? ...

    Incorrect

    • Dicrotic notch is produced by which valves?

      Your Answer:

      Correct Answer: Aortic

      Explanation:

      The graph of aortic pressure throughout the cardiac cycle displays a small dip (the incisure or dicrotic notch) which coincides with the aortic valve closure. The dip in the graph is immediately followed by a brief rise (the dicrotic wave) then gradual decline.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 94 - How many molecules of myosin attach to actin at any given time? ...

    Incorrect

    • How many molecules of myosin attach to actin at any given time?

      Your Answer:

      Correct Answer: 1

      Explanation:

      1 molecule of myosin binds to actin at any give time.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 95 - Coronary flow is reduced during ...

    Incorrect

    • Coronary flow is reduced during

      Your Answer:

      Correct Answer: Tachycardia

      Explanation:

      Maximum amount of blood flow in the coronary arteries occur during diastole. When the heart rate increases which is also called tachycardia the duration of diastole decreases. Hence the amount of blood flow to the cardiac muscle also decreases.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 96 - Which of the following concerning PR interval is INCORRECT? ...

    Incorrect

    • Which of the following concerning PR interval is INCORRECT?

      Your Answer:

      Correct Answer: Always measured from the beginning of p wave to the beginning of r wave

      Explanation:

      The PR interval measures the time from the start of atrial depolarization to the start of ventricular depolarization. The PR interval is only measured from the beginning of P wave to beginning of R wave if the Q wave is absent.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 97 - Regarding cardiac contractility, catecholamines exert their inotropic effect via: ...

    Incorrect

    • Regarding cardiac contractility, catecholamines exert their inotropic effect via:

      Your Answer:

      Correct Answer: Β1-adrenergic receptors and gs

      Explanation:

      Catecholamines exert their inotropic effect on the heart via the B1 adrenergic receptors and Gs, stimulating adenyl cyclase and increasing the production of cAMP.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 98 - Which structure forms the major part of the sternocostal surface of the heart?...

    Incorrect

    • Which structure forms the major part of the sternocostal surface of the heart?

      Your Answer:

      Correct Answer: Right ventricle

      Explanation:

      The anterior (sternocostal) surface is formed mainly by the right ventricle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 99 - In a 30 year old male with hypertrophic obstructive cardiomyopathy (HOCM), which of...

    Incorrect

    • In a 30 year old male with hypertrophic obstructive cardiomyopathy (HOCM), which of the following is not associated with increased risk of sudden death?

      Your Answer:

      Correct Answer: Age

      Explanation:

      Hypertrophic cardiomyopathy (HCM) is a disease in which a portion of the myocardium (heart muscle) is enlarged without any obvious cause, creating functional impairment of the heart. It is the leading cause of sudden death in young athletes. The major risk factors for sudden death (SD) are recent unexplained syncope unlikely to be neurocardiogenic; HCM-related SD in first-degree or other close relatives; repetitive and/or prolonged nonsustained ventricular tachycardia (NSVT) episodes on Holter or extended ambulatory monitoring; massive left ventricular hypertrophy (LVH) (wall thickness ≥30 mm); extensive/diffuse late gadolinium enhancement (LGE); end-stage heart failure usually with systolic dysfunction; and thin-walled akinetic LV apical aneurysm with regional scarring.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 100 - Myocardium requires more oxygen to expel blood in: ...

    Incorrect

    • Myocardium requires more oxygen to expel blood in:

      Your Answer:

      Correct Answer: A stenotic aortic valve

      Explanation:

      In aortic valve stenosis, increased ventricular pressure Is needed to expel the blood into the aorta. Increased pressure means increased contractility hence increase O2 consumption by the heart muscles.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (1/1) 100%
Medicine (1/1) 100%
Passmed
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