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  • Question 1 - 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
      5.7
      Seconds

  • Question 2 - During which phase of the cardiac cycle does most of the ventricular filling...

    Correct

    • During which phase of the cardiac cycle does most of the ventricular filling occur?

      Your Answer: Ventricular diastole

      Explanation:

      During the phase of ventricular diastole when the heart muscle relaxes and all the valves are open, blood flows easily into the heart. This is the phase of rapid ventricular filling. During isovolumetric contraction and relaxation the volume of blood in the heart does not change. During ventricular ejection blood enters into the aorta and pulmonary vessels.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.4
      Seconds

  • Question 3 - Xanthines (for example Caffeine), exhibit their positive inotropic effect by: ...

    Correct

    • Xanthines (for example Caffeine), exhibit their positive inotropic effect by:

      Your Answer: Inhibiting the breakdown cAMP

      Explanation:

      Xanthines exert their positive inotropic effect by inhibiting the breakdown of the cAMP resulting in stronger and sustained contraction.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      2.5
      Seconds

  • Question 4 - According to Poiseuille’s formula, which 1 of the following will lead to increased...

    Correct

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

      Your 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
      5.5
      Seconds

  • Question 5 - Which part of the ECG represents ventricular repolarisation? ...

    Correct

    • Which part of the ECG represents ventricular repolarisation?

      Your Answer: T wave

      Explanation:

      Ventricular repolarisation is denoted by the T wave.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.6
      Seconds

  • Question 6 - Which of the following normally has a slow depolarizing “prepotential”? ...

    Correct

    • Which of the following normally has a slow depolarizing “prepotential”?

      Your Answer: Sinoatrial node

      Explanation:

      There are 2 main types of action potentials (AP) in the heart, the slow response and the fast response:The slow response is initiated by the slow calcium-sodium channels, found in the SA node (which is the natural pacemaker of the heart) and the conduction fibers of the AV node.The fast response occurs in the atrial and ventricles muscle cells and the purkinje fibers.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.7
      Seconds

  • Question 7 - 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
      2.8
      Seconds

  • Question 8 - Cholinergic nerves from the vagus innervate the SA and AV nodes via which...

    Correct

    • Cholinergic nerves from the vagus innervate the SA and AV nodes via which receptor in the heart?

      Your Answer: M2 receptor

      Explanation:

      M2 receptor is found in the heart. M3 and M4 are associated with smooth muscle.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.7
      Seconds

  • Question 9 - What is the isolated effect of B2 stimulation on the coronaries? ...

    Correct

    • What is the isolated effect of B2 stimulation on the coronaries?

      Your Answer: Vasodilatation

      Explanation:

      Norepinephrine and epinephrine are agonists for all adrenergic receptor subtypes, although with varying affinities. Based on their physiology and pharmacology, adrenergic receptors have been divided into two principal types: alpha and beta. These types have been further differentiated into alpha-1, alpha-2, b1, and b2 receptors.

      Alpha-1 Receptors are located on postsynaptic cells in smooth muscle and elicit vasoconstriction.

      Alpha-2 receptors are localized on presynaptic membranes of postganglionic nerve terminals that synthesize norepinephrine. When activated by catecholamines, alpha-2 receptors act as negative feedback controllers, inhibiting further norepinephrine release.

      Activation of myocardial b1 receptors stimulates the rate and strength of cardiac contraction, and consequently increases cardiac output. b1 Receptor activation also stimulates renin release from the kidney. Another class of antihypertensive agents acts by inhibiting b1 receptors.

      Activation of b2 receptors by epinephrine relaxes vascular smooth muscle and results in vasodilation.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      7.2
      Seconds

  • Question 10 - In which organ will you find extremely porous sinusoidal capillaries, with discontinuous endothelium?...

    Correct

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

      Your 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
      5.8
      Seconds

  • Question 11 - Cross-bridges between actin and myosin filaments contain: ...

    Correct

    • Cross-bridges between actin and myosin filaments contain:

      Your 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
      10.7
      Seconds

  • Question 12 - The following determines the strength of contraction ...

    Correct

    • The following determines the strength of contraction

      Your 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
      13.2
      Seconds

  • Question 13 - 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
      9.6
      Seconds

  • Question 14 - Which of the following is first to rise following myocardial infarction? ...

    Correct

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

      Your 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
      5.9
      Seconds

  • Question 15 - The following contributes to the rate of depolarization? ...

    Correct

    • The following contributes to the rate of depolarization?

      Your Answer: All of the options given

      Explanation:

      Depolarization occurs due to impulses generated by the SA node. As the heart beats to the rhythm of the SA node, certain factors will effect the rate of depolarization. All the mentioned options effect the rate of depolarization.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.6
      Seconds

  • Question 16 - Which heart sounds are matched correctly? ...

    Correct

    • Which heart sounds are matched correctly?

      Your 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
      5.8
      Seconds

  • Question 17 - When looking at the JVP what does the c wave signify: ...

    Correct

    • When looking at the JVP what does the c wave signify:

      Your Answer: Isovolumetric ventricular contraction

      Explanation:

      The C wave signifies a rise in the atrial pressure during isovolumetric contraction due to the tricuspid valve bulging into the atria.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      6.1
      Seconds

  • Question 18 - What is pulse pressure? ...

    Correct

    • What is pulse pressure?

      Your 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
      3.2
      Seconds

  • Question 19 - Transport of Ca2+ into the reticulum to initiate cardiac muscle relaxation in via:...

    Incorrect

    • Transport of Ca2+ into the reticulum to initiate cardiac muscle relaxation in via:

      Your Answer: Voltage-gated Ca2+ channels

      Correct Answer: Serca (sarcoplasmic or endoplasmic reticulum Ca2+ ATPase)

      Explanation:

      Phosphorylation of phospholamban, which increases calcium ATPase activity and sequestration of calcium in the sarcoplasmic reticulum. An increased rate of relaxation is explained because cAMP also activates the protein phospholamban, situated on the membrane of the SR, that controls the rate of uptake of calcium into the SR. The latter effect explains enhanced relaxation (lusitropic effect).

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      22.6
      Seconds

  • Question 20 - Which vaso metabolite decreases coronary blood flow? ...

    Correct

    • Which vaso metabolite decreases coronary blood flow?

      Your 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
      8.5
      Seconds

  • Question 21 - The function of ATP in cardiac muscle contraction includes: ...

    Correct

    • The function of ATP in cardiac muscle contraction includes:

      Your 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
      3.7
      Seconds

  • Question 22 - The internodal tract of Bachman: ...

    Incorrect

    • The internodal tract of Bachman:

      Your Answer: Connects the AV node to the rest of the heart

      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
      12.1
      Seconds

  • Question 23 - Describe the location of the SA node: ...

    Correct

    • Describe the location of the SA node:

      Your Answer: Junction of the SVC and right atrium

      Explanation:

      Anatomically the SA node is located at the junction of the superior vena cava and the right atrium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      12.8
      Seconds

  • Question 24 - Which of the following is the most common causative organism in infective endocarditis?...

    Correct

    • Which of the following is the most common causative organism in infective endocarditis?

      Your Answer: Streptococcus viridans

      Explanation:

      Viridans Alpha-haemolytic streptococci, that are present in the mouth are the most frequently isolated microorganisms when the infection is acquired in a community setting. In contrast, Staphylococcus blood stream infections are frequently acquired in a health care setting where they can enter the blood stream through procedures that cause break in the integrity of skin like surgery, catheterisation or during access of long term indwelling catheters or secondary to intravenous injection of recreational drugs.Prosthetic valve endocarditis is commonly caused by Staphylococcus epidermidis as it is capable of growing as a biofilm on plastic surfaces

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      2.5
      Seconds

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

    Correct

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

      Your 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
      6.3
      Seconds

  • Question 26 - The following are examples of the functions of the vascular endothelium except: ...

    Correct

    • The following are examples of the functions of the vascular endothelium except:

      Your Answer: Tumour suppression

      Explanation:

      Vascular endothelium has many important functions including regulation of vascular tone, molecular exchange between blood and tissue compartments, hemostasis and signaling for the immune regulation and inflammation. Depending on specific tissue needs and local stresses, endothelial cells are capable of evoking either antithrombotic or prothrombotic events. Tumor suppression is related to genes, or anti-oncogenes, that regulate a cell during cell division and replication.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.8
      Seconds

  • Question 27 - Blood flow to the subendocardial portions of the left ventricular muscle occurs mainly...

    Correct

    • Blood flow to the subendocardial portions of the left ventricular muscle occurs mainly during:

      Your Answer: Diastole

      Explanation:

      The sub endocardium receives the least amount of blood from the coronary arteries. During systole the coronary arteries collapse as a result of the pressure from 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 sub endocardium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      5.4
      Seconds

  • Question 28 - The branche(s) of the left coronary artery include: ...

    Correct

    • The branche(s) of the left coronary artery include:

      Your Answer: Left circumflex artery & anterior interventricular artery

      Explanation:

      The left main coronary divides into branches:

      1. The left anterior descending artery branches off the left coronary artery and supplies blood to the front of the left side of the heart.

      2. The circumflex artery branches off the left coronary artery and encircles the heart muscle.

      The anterior interventricular artery is otherwise known as the anterior descending branch. The posterior descending artery comes from Right coronary artery.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.7
      Seconds

  • Question 29 - Pacemaker cells in the SA node and the AV node are connected by?...

    Correct

    • Pacemaker cells in the SA node and the AV node are connected by?

      Your Answer: Gap junctions

      Explanation:

      Gap junctions allows for rapid propagation of the action potential from one cell to the other. The cells of the heart are connected by gap junctions.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      4.8
      Seconds

  • Question 30 - 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
      5.9
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (28/30) 93%
Medicine (28/30) 93%
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