00
Correct
00
Incorrect
00 : 00 : 00
Session Time
00 : 00
Average Question Time ( Secs)
Retry this test Dashboard

  • Question 1 - The following is true of the sinus node: ...

    Correct

    • The following is true of the sinus node:

      Your Answer: It generates impulses automatically & at a quicker rate than other cardiac cells

      Explanation:

      The SA node exhibits automaticity. It generates the impulses to which the heart beats. It fires at a faster speed than the rest of the nervous components of the heart i.e. the AV nodes, purkinje fibers. This is the reason when the SA node fails the heart beats to the rhythm of the AV node.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      1.3
      Seconds

  • Question 2 - 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
      0.6
      Seconds

  • Question 3 - The direct determinants of cardiac output are ...

    Incorrect

    • The direct determinants of cardiac output are

      Your Answer: Ejection fraction and stroke volume

      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
      0.7
      Seconds

  • Question 4 - Cholinergic vagal supply to the SA and AV nodes results in slowing of...

    Incorrect

    • Cholinergic vagal supply to the SA and AV nodes results in slowing of the heart rate via:

      Your Answer: Dopaminergic receptors

      Correct Answer: M2 muscarinic receptors

      Explanation:

      M2 muscarinic receptors are the receptors for the parasympathetic system to the SA and the AV node.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0.9
      Seconds

  • Question 5 - Coronary arteries arise from? ...

    Incorrect

    • Coronary arteries arise from?

      Your Answer: Aortic arch

      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
      0.6
      Seconds

  • Question 6 - Which of the following structures of the cardiac conduction system is located in...

    Correct

    • Which of the following structures of the cardiac conduction system is located in the right posterior portion of the interatrial septum?

      Your Answer: AV node

      Explanation:

      AV node is located at the right posterior portion of the interatrial septum.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0.6
      Seconds

  • Question 7 - 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: 3

      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
      0.8
      Seconds

  • Question 8 - Most of the venous blood returns to the heart through the: ...

    Incorrect

    • Most of the venous blood returns to the heart through the:

      Your Answer: Right ventricle

      Correct Answer: Coronary sinus and anterior cardiac veins

      Explanation:

      Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins which drain into the right atrium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      1
      Seconds

  • Question 9 - Normal stroke volume is about: ...

    Incorrect

    • Normal stroke volume is about:

      Your Answer: 100 ml

      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
      0.8
      Seconds

  • Question 10 - In which area is depolarization initiated? ...

    Incorrect

    • In which area is depolarization initiated?

      Your Answer: Atria

      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
      0.7
      Seconds

  • Question 11 - 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: Left circumflex artery

      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
      0.8
      Seconds

  • Question 12 - 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: Ascending aorta

      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
      0.7
      Seconds

  • Question 13 - The following are examples of the functions of the vascular endothelium except: ...

    Incorrect

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

      Your Answer: Prothrombotic

      Correct 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
      0.6
      Seconds

  • Question 14 - Blood flow to the subendocardial portions of the left ventricular muscle occurs mainly...

    Incorrect

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

      Your Answer: Isovolumetric ventricular contraction

      Correct 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
      0.8
      Seconds

  • Question 15 - Regarding cardiac output, an increased ejection fraction results from increases in which of...

    Correct

    • Regarding cardiac output, an increased ejection fraction results from increases in which of the following?

      Your Answer: Strength of contraction without increase in muscle fiber length

      Explanation:

      When the strength of contraction increases without an increase in fiber length, the EF increases.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0.8
      Seconds

  • Question 16 - 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: Left marginal artery

      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
      0.5
      Seconds

  • Question 17 - 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 18 - The basic unit of contraction in myocytes is: ...

    Incorrect

    • The basic unit of contraction in myocytes is:

      Your Answer:

      Correct Answer: Sarcomere

      Explanation:

      Sarcomere is the organelle where calcium is stored to be released during contraction of the muscle. It is the basic unit of contraction in striated muscle fibers. As myocytes are also striated muscles, sarcomeres also forms the basic unit of contraction. The impulses travel along the membrane and via its interaction with the dihydropyridine receptors it releases the stored calcium.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 19 - The celiac trunk consists of which arteries? ...

    Incorrect

    • The celiac trunk consists of which arteries?

      Your Answer:

      Correct Answer: Left gastric, common hepatic, splenic

      Explanation:

      The celiac trunk is the first major branch of the abdominal aorta. It is 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12). There are three main divisions of the celiac artery:- left gastric artery- common hepatic artery- splenic artery

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 20 - The isoforms of nitric oxide synthase which are found in the nervous system...

    Incorrect

    • The isoforms of nitric oxide synthase which are found in the nervous system (NOS1) and endothelial cells (NOS3) are activated by agents that increase which of the following intracellular electrolytes?

      Your Answer:

      Correct Answer: Ca

      Explanation:

      Synthesis of nitric oxide is stimulated by activation of the NMDA receptors by certain agents. This leads to opening of the Calcium channels and an influx of calcium into the cell. This will activate the nitric oxide synthase. Nitric oxide is produced on demand.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 21 - 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 22 - 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 23 - 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 24 - Nitric oxide triggers vascular smooth muscle contraction through activation of which enzyme? ...

    Incorrect

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

      Your Answer:

      Correct 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
      0
      Seconds

  • Question 25 - Calcium is mobilized from the sarcoplasmic reticulum through: ...

    Incorrect

    • Calcium is mobilized from the sarcoplasmic reticulum through:

      Your Answer:

      Correct Answer: Ryanodine receptor (RyR2) calcium release channels

      Explanation:

      During the plateau phase of the action potential, calcium from the extracellular fluid enters through the L type of calcium channels. This entry triggers the release of more calcium from the sarcoplasmic reticulum via the ryanodine receptors. As a result intracellular calcium increases binding to troponin C resulting in contraction.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 26 - 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 27 - 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 28 - 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 29 - The initial rapid depolarization in the action potential of cardiac muscle cells is...

    Incorrect

    • The initial rapid depolarization in the action potential of cardiac muscle cells is due to:

      Your Answer:

      Correct Answer: Opening of voltage-gated Na+ channels

      Explanation:

      The initial depolarization of the action potential in a cardiac muscle cell is due to the sodium current generated by opening of the voltage gated sodium channels leading to an influx of sodium ions into the cell and raising the membrane potential towards threshold.

    • This question is part of the following fields:

      • Cardiovascular
      • Medicine
      0
      Seconds

  • Question 30 - 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

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular (4/16) 25%
Medicine (4/16) 25%
Passmed
Retry this test Dashboard