Case 2 Questions 1-10

This section is devoted to SBA style questions on Case 2.

We hope you find these useful in your revision.

Enjoy working thorugh the following questions. We hope they aid your learning. If you have any issues or feedback, please email [email protected].

Question 1

Describe the conduction pathway of the heart

  1. Atrial fibers – SAN – purkinje fibers – AVN – Bundle of His – Ventricular fibers
  2. SAN – atrial fibers – AVN – Bundle of His – Purkinje fibers – Ventricular fibers
  3. SAN – atrial fibers – AVN – Purkinje fibers – Bundle of His – Ventricular fibers
  4. SAN –AVN – atrial fibers – Bundle of His – ventricular fibers – purkinje fibers
  5. AVN – atrial fibers – SAN – Bundle of His – Purkinje fibers – ventricular fibers

The correct answer is option b SAN – atrial fibers – AVN – Bundle of His – Purkinje fibers – Ventricular fibers

b is correct as the conduction pathway is generated in the sino-atrial node, travels through the atria until it reaches the ventricular atrial node, where there is a slight delay before going down the bundle of his, purkinje fibres then through the ventricular fibres
a. Is incorrect as the SAN generates the AP, not the Atrial fibres and comes throught the AVN before the purkinje fibres
c. The charge goes down the bundle of his before the purkinje fibres
d. The charge goes down the atrial fibres before the AVN
e. The charge is generated in the SAN, not the AVN

Question 2

Which of the following ECG abnormalities is typically seen in first degree heart block?

  1. PR interval >120 ms
  2. PR interval >300 ms
  3. PR interval <200 ms
  4. PR interval >200 ms
  5. PR interval <120 ms

The correct answer is option d PR interval >200 ms

200ms is correct, it is equivilent to 1 large square on the ECG
a. Incorrect, 1st degree heart block is 1 large square, not 3 small squares
b. Whilst 1st degree heartblock can be over 300ms it is diagnostic over 200ms
c. PR interval of under 200 is not heartblock
e. PR interval of under 120ms is not heartblock

Question 3

What is the pacemaker rate of the AVN

  1. 70BPM
  2. 60BPM
  3. 50BPM
  4. 40BPM
  5. 30BPM

The correct answer is option d 40BPM

The correct answer is 50BPM, as this is the rate of depolarisation
a. Incorrect
b. Incorrect
c. Incorrect
e. Incorrect

Question 4

A patient has shortness of breath that is relieved when sitting up, what is most likely to be causing this?

  1. Left sided heart faliure
  2. Right sided heart faliure
  3. Asthma
  4. Anaphylaxis
  5. Myocardial infarction

The correct answer is option a Left sided heart faliure

Left sided heart faliure is correct as the blood cannot be moved into systemic circulation, so backflows into the lung causing Pulmonary Oedema – causes SOB when lying
b. This would cause peripheral oedema
c. This would cause SOB on exertion and if the SOB occured when lying then it would not be relieved on sitting up
d. As with asthma the SOB would not be relieved when sitting up
e. This would have severe chest pain as the most prominent symptom

Question 5

Which heart valve only contains 2 cusps?

  1. Aortic valve
  2. Mitral valve
  3. Tricuspid valve
  4. Pulmonary Valve
  5. Semi-Lunar valve

The correct answer is option b Mitral valve

This is correct, the mitral valve is also known as the bicuspid valve
a. Incorrect this has 3 flaps
c. Incorrect this has 3 flaps
d. The pulmonary valve has 3 flaps
e. Both semi-lunar valves have 3 flaps, they are the aortic and pulmonary valves

Question 6

From which embryonic germ layer does the heart develop from?

  1. Paraxial mesoderm
  2. Somatic mesoderm
  3. Extraembryonic mesoderm
  4. Ectoderm
  5. Splanchnic mesoderm

The correct answer is option e Splanchnic mesoderm

The splanchic mesoderm forms the second heart field, the GI connective tissues and others
a. The paraxial mesoderm is responsible for neuralating the embryo and making the neural tube
b. The somatic mesoderm forms the notochord
c. These forms the gonads
d. The ectoderm is responsible for making the epidermis and nerve tissues

Question 7

A 50-year-old woman has presented to her local emergency department as she is having persistent palpitations. An ECG shows a fast irregular rhythm with no visible P waves.

  1. Asystole
  2. Atrial flutter
  3. Atrial fibrilation
  4. Ventricular fibrillation
  5. Ventricular tachycardia

The correct answer is option c Atrial fibrilation

AFib would have no P waves and an irregular rhythm as the AVN would be depolarised randomly as the electrical activity reaches it
a. Asystole would have no rhythm and would be a single line with minimal electrical activity
b. Atrial flutter would have shark tooth like p waves
d. Vfib would have o visible QRS segments
e. VTac would have regular, fast QRS segments

Question 8

A 60-year-old male suffered a myocardial infarction and had a heart rate of 40beats/min. His right coronary artery was occluded. Select the structure that is most likely to be affected.

  1. AV node
  2. Bundle of His
  3. Purkinje fibres
  4. Right bundle branch
  5. SA node

The correct answer is option a AV node

AV node is correct as this would cause a ventricular tachycardia and ATac
b.
c. Incorrect as this is supplied by the left anterior descending artery
d. Incorrect as this would cause right sided heart faliure
e. Incorrect as this would cause 3rd degree heart block

Question 9

During development, the cardiovascular system is active from which week?

  1. Week 2
  2. Week 3
  3. Week 4
  4. Week 5
  5. Week 6

The correct answer is option c Week 4

4 weeks is correct
a. This is incorrect
b. This is incorrect
d. This is incorrect
e. This is incorrect

Question 10

Which of these is not a feature of Tetralogy of Fallot?

  1. Ventricular Septal Defect
  2. Overriding aorta
  3. Left ventricular hypertrophy
  4. Pulmonary stenosis
  5. Right ventricular hypertrophy

The correct answer is option c Left ventricular hypertrophy

Correct, LVHT is not seen in the tetralogy of fallot
a. VSD is seen in the tetralogy of fallot
b. Overriding aorta is seen in the tetralogy of fallot
d. Pulmonary stenosis is seen in the tetralogy of fallot
e. RVHT is seen in the tetralogy of fallot