A 64-year-old man with chest pain has sinus bradycardia and, later, sinus pauses on the monitor. Angiography shows a proximal occlusion of the right coronary artery. In most people, from which artery does the sinoatrial nodal artery arise?

Posterior interventricular artery

Left anterior descending artery

A 68-year-old hypertensive man has had a hoarse voice for 2 months. Laryngoscopy shows a paralysed left vocal cord, and CT of the chest shows an aneurysm of the arch of the aorta. Which nerve is affected, and why on the left?

Left recurrent laryngeal, which hooks under the arch

Left phrenic, which crosses in front of the aortic arch

Left vagus trunk, which runs behind the root of the lung

Left external laryngeal, which runs with the superior thyroid artery

Heart, coronary circulation and mediastinum

12 NEET-PG practice questions on Heart, coronary circulation and mediastinum, part of Anatomy. The first 12 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 9-year-old girl is undergoing closure of a muscular ventricular septal defect. The surgeon points out a muscular band in the right ventricle running from the septum to the base of the anterior papillary muscle and warns that it must not be cut. Which conducting tissue runs in this band?
1. ABundle of His
2. BRight bundle branch
3. CLeft anterior fascicle
4. DBachmann bundle
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Answer: B · Right bundle branch
The muscular band is the septomarginal trabecula (moderator band). It carries the right bundle branch from the septum to the base of the anterior papillary muscle, so that this muscle contracts in time to tense the tricuspid cusps before ventricular systole. Dividing it would delay activation of that part of the right ventricle. The band also helps to prevent overdistension of the right ventricle, which is how it got its name.
- A: The bundle of His runs in the membranous septum before dividing, not in the moderator band.
- C: The left anterior fascicle runs on the left side of the septum to the anterolateral papillary muscle.
- D: Bachmann bundle connects the right and left atria.
Question 2 · Medium
During cardiac surgery on a 58-year-old woman, the surgeon passes a finger behind the ascending aorta and pulmonary trunk, in front of the superior vena cava and atria, to pass a tape around the great arteries. Through which space does the finger pass?
1. ATransverse pericardial sinus
2. BRetrosternal space
3. COblique pericardial sinus
4. DCostomediastinal recess
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Answer: A · Transverse pericardial sinus
The transverse sinus of the pericardium is the passage between the arterial reflection of serous pericardium (around the aorta and pulmonary trunk) and the venous reflection (around the SVC and pulmonary veins). A finger in it lies behind the great arteries and in front of the SVC and atria, so the surgeon can pass a ligature or clamp around the aorta and pulmonary trunk during cardiac surgery. The oblique sinus is a blind recess behind the left atrium and cannot be passed through.
- B: The retrosternal space lies in front of the pericardium, not behind the great arteries.
- C: The oblique sinus is a blind pocket behind the left atrium.
- D: The costomediastinal recess is a pleural, not pericardial, space.
Question 3 · Hard
A 62-year-old man with an inferior STEMI from a proximal right coronary occlusion (right-dominant heart) develops second-degree AV block with a narrow QRS on day 1. The intern lists four statements: 1. The AV nodal artery usually arises from the artery that gives the posterior interventricular branch. 2. The SA nodal artery arises from the LAD in most people. 3. AV block in inferior infarction is usually at the AV node and often transient. 4. The posterior third of the septum is supplied by the LAD. Which are correct?
1. A1, 2, 3 and 4
2. B1 and 3 only
3. C1 and 2 only
4. D3 and 4 only
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Answer: B · 1 and 3 only
Statements 1 and 3 are correct. The AV nodal artery arises at the crux from the dominant artery, the RCA in a right-dominant heart, so an RCA occlusion causes nodal ischaemia; the block is at the AV node, has a narrow QRS escape and usually resolves, often needing only atropine or temporary pacing. Statement 2 is wrong: the SA nodal artery arises from the RCA in about 60% and from the circumflex in most others, not the LAD. Statement 4 is wrong: the posterior third of the septum is supplied by the posterior interventricular artery.
- A: Includes statements 2 and 4, both of which are false.
- C: Includes statement 2, but the SA nodal artery does not come from the LAD, and leaves out 3.
- D: Leaves out statement 1 and includes 4; the posterior septum is supplied by the posterior interventricular artery.
Question 4 · Easy
A 64-year-old man with chest pain has sinus bradycardia and, later, sinus pauses on the monitor. Angiography shows a proximal occlusion of the right coronary artery. In most people, from which artery does the sinoatrial nodal artery arise?
1. ARight coronary artery
2. BPosterior interventricular artery
3. CLeft circumflex artery
4. DLeft anterior descending artery
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Answer: A · Right coronary artery
The sinoatrial nodal artery arises from the right coronary artery in about 60% of people and from the circumflex branch of the left coronary artery in most of the rest. It runs up to the junction of the superior vena cava and right atrium, where the node lies. A proximal RCA occlusion can therefore cause sinus bradycardia or sinus arrest. These rhythms often recover, but symptomatic bradycardia may need atropine or temporary pacing.
- B: The posterior interventricular artery supplies the posterior septum, not the SA node.
- C: The circumflex gives the nodal artery in a minority of people.
- D: The LAD supplies the anterior septum and anterior wall, not the SA node.
Question 5 · Medium
A 68-year-old hypertensive man has had a hoarse voice for 2 months. Laryngoscopy shows a paralysed left vocal cord, and CT of the chest shows an aneurysm of the arch of the aorta. Which nerve is affected, and why on the left?
1. ALeft phrenic, which crosses in front of the aortic arch
2. BLeft vagus trunk, which runs behind the root of the lung
3. CLeft recurrent laryngeal, which hooks under the arch
4. DLeft external laryngeal, which runs with the superior thyroid artery
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Answer: C · Left recurrent laryngeal, which hooks under the arch
The left recurrent laryngeal nerve arises from the vagus in the thorax as it crosses the arch of the aorta, hooks below the arch lateral to the ligamentum arteriosum and climbs in the groove between the trachea and oesophagus to the larynx. An arch aneurysm, nodes in the aortopulmonary window or a lung cancer there can stretch or compress it, paralysing the left vocal cord. The right nerve hooks around the right subclavian artery, higher in the neck, so it is not affected by arch disease. A new hoarse voice for more than 3 weeks needs laryngoscopy and chest imaging.
- A: The phrenic nerve supplies the diaphragm, not the larynx.
- B: The vagus trunk below the arch no longer carries the recurrent laryngeal fibres.
- D: The external laryngeal nerve supplies cricothyroid and lies in the neck, away from the arch.
Question 6 · Medium
During coronary artery bypass surgery on a 61-year-old man, the surgeon opens the epicardial fat over the anterior interventricular groove to expose the LAD for the graft and finds a vein running alongside the artery. Which vein is it?
1. AAnterior cardiac vein
2. BGreat cardiac vein
3. CMiddle cardiac vein
4. DSmall cardiac vein
Answer and explanation in LearnFree account
Question 7 · Hard
A 58-year-old smoker with a right hilar mass has had swelling of the face and both arms for 3 weeks. Dilated veins run over the front of the chest and upper abdomen; when the blood is stripped from them, they refill from above downwards, towards the groin. CT confirms superior vena cava obstruction. Where is the block most likely to be?
1. ASVC at or below the entry of the azygos vein
2. BIVC just below the hepatic veins
3. CLeft brachiocephalic vein alone
4. DSVC above the entry of the azygos vein
Answer and explanation in LearnFree account
Question 8 · Easy
A 70-year-old man with heart failure is having a cardiac resynchronisation device implanted, and the cardiologist must pass a lead into the coronary sinus. Where does the coronary sinus open?
1. ALeft atrium, between the pulmonary vein openings
2. BRight ventricle, just below the septal tricuspid cusp
3. CSuperior vena cava, near its junction with the right atrium
4. DRight atrium, between the IVC opening and the tricuspid orifice
Answer and explanation in LearnFree account
Question 9 · Medium
A 52-year-old man has crushing central chest pain that spreads to the inner side of the left arm. Which pathway explains why cardiac pain is felt in the arm?
1. AIntercostal nerve afferents from the chest wall
2. BPhrenic afferents from the pericardium to C3-C5
3. CVagal afferents to the nucleus tractus solitarius
4. DVisceral afferents with sympathetic nerves to T1-T4
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Question 10 · Medium
A 50-year-old woman has crushing chest pain. Her ECG shows ST elevation in V1-V4 and a new right bundle branch block. Occlusion at which site best explains both findings?
1. AProximal circumflex, before its first marginal
2. BProximal LAD, before its first septal branch
3. CDistal LAD, beyond its diagonal branches
4. DRight coronary artery at the acute margin
Answer and explanation in LearnFree account
Question 11 · Medium
A 34-year-old woman with rheumatic mitral stenosis complains that solid food sticks behind the lower sternum. A barium swallow shows a smooth indentation on the anterior wall of the mid-oesophagus. Which chamber is causing the indentation?
1. ARight atrium
2. BRight ventricle
3. CLeft ventricle
4. DLeft atrium
Answer and explanation in LearnFree account
Question 12 · Medium
A 55-year-old man presents with ST elevation in leads II, III and aVF. Angiography shows a completely occluded left circumflex artery that continues in the posterior atrioventricular groove to the crux, and a small right coronary artery that ends at the right border of the heart. Why has a circumflex occlusion caused an inferior infarct?
1. AThe circumflex wraps around the apex to the inferior wall
2. BThe circumflex gives septal branches to the anterior septum
3. CThe circumflex gives the posterior interventricular artery
4. DThe circumflex supplies the inferior wall through the SA nodal artery
Answer and explanation in LearnFree account

Heart, coronary circulation and mediastinum

A 9-year-old girl is undergoing closure of a muscular ventricular septal defect. The surgeon points out a muscular band in the right ventricle running from the septum to the base of the anterior papillary muscle and warns that it must not be cut. Which conducting tissue runs in this band?

During cardiac surgery on a 58-year-old woman, the surgeon passes a finger behind the ascending aorta and pulmonary trunk, in front of the superior vena cava and atria, to pass a tape around the great arteries. Through which space does the finger pass?

A 64-year-old man with chest pain has sinus bradycardia and, later, sinus pauses on the monitor. Angiography shows a proximal occlusion of the right coronary artery. In most people, from which artery does the sinoatrial nodal artery arise?

A 68-year-old hypertensive man has had a hoarse voice for 2 months. Laryngoscopy shows a paralysed left vocal cord, and CT of the chest shows an aneurysm of the arch of the aorta. Which nerve is affected, and why on the left?

During coronary artery bypass surgery on a 61-year-old man, the surgeon opens the epicardial fat over the anterior interventricular groove to expose the LAD for the graft and finds a vein running alongside the artery. Which vein is it?

A 70-year-old man with heart failure is having a cardiac resynchronisation device implanted, and the cardiologist must pass a lead into the coronary sinus. Where does the coronary sinus open?

A 52-year-old man has crushing central chest pain that spreads to the inner side of the left arm. Which pathway explains why cardiac pain is felt in the arm?

A 50-year-old woman has crushing chest pain. Her ECG shows ST elevation in V1-V4 and a new right bundle branch block. Occlusion at which site best explains both findings?

A 34-year-old woman with rheumatic mitral stenosis complains that solid food sticks behind the lower sternum. A barium swallow shows a smooth indentation on the anterior wall of the mid-oesophagus. Which chamber is causing the indentation?