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  • Question 1 - The bradycardia that occurs in patients with raised intracranial pressure is a result...

    Correct

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

      Your 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
      8.5
      Seconds

  • Question 2 - Factors influencing cardiac output include which of the following? ...

    Incorrect

    • Factors influencing cardiac output include which of the following?

      Your Answer: Stroke volume

      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
      16.2
      Seconds

  • Question 3 - Isovolumetric ventricular contraction lasts for? ...

    Incorrect

    • Isovolumetric ventricular contraction lasts for?

      Your Answer: 0.25 s

      Correct Answer: 0,05 s

      Explanation:

      Isovolumetric contraction lasts for about 0.05 seconds.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      8.9
      Seconds

  • Question 4 - Myocardial contractility is improved by: ...

    Correct

    • Myocardial contractility is improved by:

      Your Answer: Caffeine

      Explanation:

      Caffeine and other theophyllines breakdown cAMP and have a positive ionotropic effect on the heart. Drugs like quinidine, procainamide and conditions like hypoxia and hypercapnia decreases the contractility of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      16.1
      Seconds

  • Question 5 - Which factor produced by the endothelium is responsible for the regulation of vascular...

    Correct

    • Which factor produced by the endothelium is responsible for the regulation of vascular cell growth?

      Your Answer: Vascular endothelial growth factor (VEGF)

      Explanation:

      VEGF is produced by the endothelial cells and is the major growth factor responsible for causing vasculogenesis. Some isoforms of this growth factor also have a prominent role in formation of lymphatic vessels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      15.3
      Seconds

  • Question 6 - The direct determinants of cardiac output are ...

    Correct

    • The direct determinants of cardiac output are

      Your 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
      6.7
      Seconds

  • Question 7 - Vasodilatation in skeletal muscle can be caused by: ...

    Incorrect

    • Vasodilatation in skeletal muscle can be caused by:

      Your Answer: Endothelin-1

      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
      13.3
      Seconds

  • Question 8 - AV valves open during? ...

    Incorrect

    • AV valves open during?

      Your Answer: When ventricular pressure exceeds the atrial pressure

      Correct Answer: Early diastole

      Explanation:

      The cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat, and so includes the diastole, the systole, and the intervening pause.The first stage, diastole, is when the semilunar valves (the pulmonary valve and the aortic valve) close, the atrioventricular (AV) valves (the mitral valve and the tricuspid valve) open, and the whole heart is relaxed. The second stage, atrial systole, is when the atrium contracts, and blood flows from atrium to the ventricle.The third stage, isovolumic contraction is when the ventricles begin to contract, the AV and semilunar valves close, and there is no change in volume. The fourth stage, ventricular ejection, is when the ventricles are contracting and emptying, and the semilunar valves are open. During the fifth stage, isovolumic relaxation time, pressure decreases, no blood enters the ventricles, the ventricles stop contracting and begin to relax, and the semilunar valves close due to the pressure of blood in the aorta.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      11
      Seconds

  • Question 9 - Relaxation of the cardiac muscle at the actin-myosin cross bridges is initiated by...

    Correct

    • Relaxation of the cardiac muscle at the actin-myosin cross bridges is initiated by binding of which molecule to the exposed site on the myosin.

      Your Answer: ATP

      Explanation:

      A crossbridge is a myosin projection, consisting of two myosin heads, that extends from the thick filaments. Each myosin head has two binding sites: one for ATP and another for actin. The binding of ATP to a myosin head detaches myosin from actin, thereby allowing myosin to bind to another actin molecule. Once attached, the ATP is hydrolysed by myosin, which uses the released energy to move into the cocked position whereby it binds weakly to a part of the actin binding site.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      14.9
      Seconds

  • Question 10 - When the heart rate is increased (to pathological levels) which of the following...

    Correct

    • 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: 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
      35.6
      Seconds

  • Question 11 - A sarcomere is the area between: ...

    Correct

    • A sarcomere is the area between:

      Your Answer: Two adjacent z lines

      Explanation:

      The area that lies between the two adjacent Z lines is known as a sarcomere and is the contractile unit of the muscle. The line passing in the middle of the myosin filaments is the M line. It also passes through the middle of the sarcomere.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      2.7
      Seconds

  • Question 12 - With regards to the cardiac cycle which of the following is true ...

    Incorrect

    • With regards to the cardiac cycle which of the following is true

      Your Answer: Left ventricular ejection begins before right ventricular ejection

      Correct Answer: Right atrial systole occurs before left atrial systole: as below

      Explanation:

      Cardiac cycle: The first event in the cycle is atrial depolarization (a P wave on the surface ECG) follows by RIGHT ATRIAL and then LEFT ATRIAL contraction. Ventricular activation (QRS) follows after a short interval (the PR interval). LEFT VENTRICULAR contraction starts shortly thereafter RIGHT VENTRICULAR contraction begins. At the end, the aortic valve closure is followed by pulmonary valve closure.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      33.7
      Seconds

  • Question 13 - 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: The aortic arch

      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
      9.4
      Seconds

  • Question 14 - 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: The left atrium

      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
      17.4
      Seconds

  • Question 15 - The coronary sinus, which empties into the right atrium, serves to? ...

    Correct

    • The coronary sinus, which empties into the right atrium, serves to?

      Your Answer: Drain the venous supply of the myocardium

      Explanation:

      The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the heart muscle (myocardium). It delivers deoxygenated blood to the right atrium, as do the superior and inferior vena cava.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      18.5
      Seconds

  • Question 16 - Nitric oxide triggers vascular smooth muscle contraction through activation of which enzyme? ...

    Correct

    • Nitric oxide triggers vascular smooth muscle contraction through activation of which enzyme?

      Your Answer: Guanylyl cyclase

      Explanation:

      Impaired production or excess catabolism of NO impairs this endothelium-dependent vasodilator function and may contribute to excessive vasoconstriction under various pathological situations.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      18.3
      Seconds

  • Question 17 - During exercise, a man consumes 2L O2/min, his arterial 02 content is 190...

    Correct

    • 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: 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
      370.3
      Seconds

  • Question 18 - According to Poiseuille’s formula, which 1 of the following will lead to increased...

    Incorrect

    • According to Poiseuille’s formula, which 1 of the following will lead to increased flow?

      Your Answer: Less turbulent flow

      Correct Answer: Shorter tube

      Explanation:

      V = π p r4 / 8 η lwhere V = discharge volume flow (m3/s)p = pressure difference between the ends of the pipe (N/m2, Pa)r = internal radius of pipe (m)l = length of pipe (m)η = viscosity of fluid

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      29
      Seconds

  • Question 19 - Tunica intima is made up of? ...

    Correct

    • Tunica intima is made up of?

      Your Answer: Endothelial cells

      Explanation:

      Tunica intima is a single cell thick lining of endothelial cells that lines the inside of the blood vessels. It is the inner most layer of the blood vessel.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.7
      Seconds

  • Question 20 - Which factors increase the end-diastolic volume? ...

    Correct

    • Which factors increase the end-diastolic volume?

      Your 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
      12.1
      Seconds

  • Question 21 - Depolarization spreads rapidly through cardiac muscle fibers because of the presence of: ...

    Correct

    • Depolarization spreads rapidly through cardiac muscle fibers because of the presence of:

      Your Answer: Gap junctions

      Explanation:

      The cardiac muscles have gap junctions in between the cells. They allow for the formation of 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
      5.3
      Seconds

  • Question 22 - The following determines the strength of contraction ...

    Incorrect

    • The following determines the strength of contraction

      Your Answer: Depolarization

      Correct Answer: Plateau phase

      Explanation:

      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 (or refractory) phase in myocyte action potential prevents early reactivation of the myocytes and directly determines the strength of contraction

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      8.4
      Seconds

  • Question 23 - Which of the following is NOT true of the parasympathetic control of the...

    Correct

    • Which of the following is NOT true of the parasympathetic control of the heart?

      Your Answer: It can be blocked by beta blockers

      Explanation:

      Parasympathetic fibers do not innervate the Beta receptors on the heart. They are innervated by the sympathetic nerve fibers. Then a beta blocker such as propranolol will block the sympathetic outflow and increase the parasympathetic tone of the heart.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      33.4
      Seconds

  • Question 24 - Which of the following best describes the cardiac muscle? ...

    Correct

    • Which of the following best describes the cardiac muscle?

      Your Answer: Striated and involuntary

      Explanation:

      Cardiac muscle (heart muscle) is an involuntary, striated muscle that is found in the walls and histological foundation of the heart, specifically the myocardium. Cardiac muscle is one of three major types of muscle, the others being skeletal and smooth muscle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      7.3
      Seconds

  • Question 25 - Which vagus nerve mainly supplies the AV node? ...

    Correct

    • Which vagus nerve mainly supplies the AV node?

      Your Answer: Left vagus

      Explanation:

      As the AV node develops from the left side of the embryo It is supplied by the left vagus nerve.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.6
      Seconds

  • Question 26 - The function of Troponin T in cardiac muscle is? ...

    Correct

    • The function of Troponin T in cardiac muscle is?

      Your Answer: Allows attachment of troponin components to tropomyosin

      Explanation:

      Troponin T binds the troponin components to tropomyosin. Troponin I inhibits the interaction of myosin with actin, and troponin C contains the binding sites for the Ca2+ that helps initiate contraction.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      13.5
      Seconds

  • Question 27 - Concerning surface anatomy, where is the aortic valve found? ...

    Incorrect

    • Concerning surface anatomy, where is the aortic valve found?

      Your Answer: Situated in the right second intercostal space underneath the sternum

      Correct Answer: Situated in the left third intercostal space underneath 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
      8
      Seconds

  • Question 28 - Which ion channel does not contribute to the myocardial action potential? ...

    Correct

    • Which ion channel does not contribute to the myocardial action potential?

      Your Answer: Chloride channel

      Explanation:

      The upstroke in the cardiac action potential is due to opening of the sodium channels and an influx of sodium into the cell. The initial repolarization phase is due to transient opening of the potassium channels along with calcium channels. Influx of calcium causes the prolonged plateau phase of the action potential. Delayed opening of the rectifier potassium channel and delayed closure of the calcium channel leads to the repolarization phase of cardiac action potential.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      13.3
      Seconds

  • Question 29 - What is cardiac output? ...

    Incorrect

    • What is cardiac output?

      Your Answer: Product of cardiac output and heart rate

      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
      4.5
      Seconds

  • Question 30 - According to Starling's law of the heart: ...

    Incorrect

    • According to Starling's law of the heart:

      Your Answer: Cardiac output is increased when the sympathetic nerves are stimulated

      Correct Answer: The extent of the preload is proportional to the end-diastolic volume

      Explanation:

      Frank starlings law 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 increased 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 the development of tension in the muscle fiber. The greater the venous return the greater the cardiac output. This relationship is directly proportional.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      15.5
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (18/30) 60%
Medicine (18/30) 60%
Passmed
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