Chapter: Anatomy
Topic: Thorax
Subtopic: Mediastinum and Esophagus
Keyword Definitions:
Esophagus: Muscular tube connecting pharynx to stomach, passes through thorax and diaphragm.
Mediastinum: Central compartment of thoracic cavity divided into superior, anterior, middle, and posterior parts.
Superior Mediastinum: Contains trachea, esophagus, great vessels, thymus remnants.
Middle Mediastinum: Contains heart, pericardium, phrenic nerves, and root of great vessels.
Posterior Mediastinum: Contains esophagus, thoracic duct, descending aorta, azygos system.
Anterior Mediastinum: Contains thymus (in children), fat, lymph nodes, connective tissue.
Clinical Relevance: Esophageal pathology may compress mediastinal structures causing dysphagia, chest pain, or dyspnea.
Lead Question - 2013
Esophagus is present in all except?
a) Superior mediastinum
b) Middle mediastinum
c) Anterior mediastinum
d) Posterior mediastinum
Explanation: The esophagus runs through superior and posterior mediastinum but not the anterior mediastinum, which mainly contains thymic tissue and fat. Middle mediastinum is primarily cardiac. Thus, the esophagus is absent from anterior mediastinum. The correct answer is c) Anterior mediastinum.
Guessed Question 2
Which structure lies immediately posterior to the left atrium in the thorax?
a) Descending thoracic aorta
b) Esophagus
c) Trachea
d) Pulmonary artery
Explanation: The esophagus lies immediately posterior to the left atrium. This close relation allows left atrial enlargement to compress the esophagus, producing dysphagia. The correct answer is b) Esophagus.
Guessed Question 3
Thoracic duct drains into venous system at the junction of?
a) Right internal jugular and subclavian vein
b) Left internal jugular and subclavian vein
c) Right brachiocephalic vein
d) Left brachiocephalic vein
Explanation: The thoracic duct ascends in the posterior mediastinum and drains into the venous system at the left internal jugular and left subclavian vein junction. The correct answer is b) Left internal jugular and subclavian vein.
Guessed Question 4
Which nerve runs anterior to the root of lung?
a) Vagus nerve
b) Phrenic nerve
c) Sympathetic trunk
d) Intercostal nerve
Explanation: The phrenic nerve runs anterior to the root of the lung within the middle mediastinum, supplying diaphragm motor innervation. The vagus nerve runs posterior to the root. The correct answer is b) Phrenic nerve.
Guessed Question 5
A patient with esophageal carcinoma shows hoarseness of voice. Which nerve is involved?
a) Right recurrent laryngeal nerve
b) Left recurrent laryngeal nerve
c) Glossopharyngeal nerve
d) Phrenic nerve
Explanation: The left recurrent laryngeal nerve, looping around the aortic arch in superior mediastinum, can be compressed by esophageal carcinoma, causing hoarseness. The correct answer is b) Left recurrent laryngeal nerve.
Guessed Question 6
At the level of T10 vertebra, the esophagus passes through?
a) Aortic hiatus
b) Caval opening
c) Esophageal hiatus
d) Foramen ovale
Explanation: The esophagus passes through diaphragm at T10 vertebral level via esophageal hiatus, accompanied by vagal trunks. The correct answer is c) Esophageal hiatus.
Guessed Question 7
Which structure passes through aortic hiatus of diaphragm at T12 level?
a) Thoracic duct
b) Esophagus
c) Inferior vena cava
d) Phrenic nerve
Explanation: The aortic hiatus at T12 transmits the descending aorta, thoracic duct, and azygos vein. The esophagus passes at T10, IVC at T8. The correct answer is a) Thoracic duct.
Guessed Question 8
Posterior mediastinum contains all except?
a) Thoracic duct
b) Azygos vein
c) Phrenic nerve
d) Esophagus
Explanation: Phrenic nerve is located in middle mediastinum, running anterior to lung roots. Posterior mediastinum includes esophagus, thoracic duct, azygos system, and descending aorta. The correct answer is c) Phrenic nerve.
Guessed Question 9
Compression of esophagus by enlarged left atrium is best seen on which investigation?
a) Barium swallow
b) Chest X-ray PA view
c) CT thorax
d) Ultrasound
Explanation: A barium swallow study shows indentation of esophagus by enlarged left atrium, producing characteristic posterior impression. The correct answer is a) Barium swallow.
Guessed Question 10
A patient with dysphagia lusoria has compression of esophagus by?
a) Aberrant right subclavian artery
b) Left common carotid artery
c) Pulmonary trunk
d) Inferior vena cava
Explanation: Dysphagia lusoria occurs when an aberrant right subclavian artery arises abnormally and compresses esophagus posteriorly, causing difficulty in swallowing. The correct answer is a) Aberrant right subclavian artery.
Guessed Question 11
Which vein drains blood from esophagus into systemic circulation?
a) Azygos vein
b) Hemiazygos vein
c) Accessory hemiazygos vein
d) All of the above
Explanation: Esophageal veins drain into azygos, hemiazygos, and accessory hemiazygos systems in posterior mediastinum, forming porto-systemic anastomosis with left gastric vein. The correct answer is d) All of the above.
Chapter: Anatomy
Topic: Thorax
Subtopic: Mediastinum and Esophagus
Keyword Definitions:
Esophagus: Muscular tube connecting pharynx to stomach, located in thorax and abdomen.
Mediastinum: Central compartment of thoracic cavity, divided into superior, anterior, middle, and posterior parts.
Posterior Mediastinum: Contains esophagus, descending thoracic aorta, thoracic duct, azygos system.
Anterior Mediastinum: Located in front of pericardium, contains thymus (in children), fat, lymph nodes.
Middle Mediastinum: Contains heart, pericardium, roots of great vessels, phrenic nerves.
Superior Mediastinum: Contains trachea, esophagus, great vessels, thymus remnants.
Clinical Relevance: Esophageal lesions may compress adjacent mediastinal structures like trachea or left atrium.
Lead Question - 2013
Esophagus is present in which mediastinum?
a) Anterior
b) Posterior
c) Middle
d) None
Explanation: The esophagus lies mainly in the posterior mediastinum, extending from superior mediastinum down to the diaphragm. It is absent from anterior and middle mediastinum. Therefore, the correct answer is b) Posterior.
Guessed Question 2
Which structure is located immediately posterior to the left atrium?
a) Trachea
b) Esophagus
c) Descending aorta
d) Pulmonary trunk
Explanation: The esophagus runs just posterior to the left atrium. Enlargement of the left atrium can compress the esophagus, leading to dysphagia. The correct answer is b) Esophagus.
Guessed Question 3
At what vertebral level does the esophagus pass through the diaphragm?
a) T8
b) T9
c) T10
d) T12
Explanation: The esophagus passes through the diaphragm at T10 vertebral level via the esophageal hiatus, accompanied by vagal trunks. The correct answer is c) T10.
Guessed Question 4
Which nerve forms the esophageal plexus in thorax?
a) Vagus nerve
b) Phrenic nerve
c) Intercostal nerve
d) Sympathetic chain
Explanation: The esophageal plexus is formed by vagus nerve fibers along with sympathetic fibers, facilitating autonomic innervation of esophagus. The correct answer is a) Vagus nerve.
Guessed Question 5
Which vein drains the thoracic esophagus?
a) Azygos vein
b) Hemiazygos vein
c) Accessory hemiazygos vein
d) All of the above
Explanation: The thoracic esophagus drains into azygos, hemiazygos, and accessory hemiazygos veins, forming porto-systemic anastomoses. The correct answer is d) All of the above.
Guessed Question 6
A patient with dysphagia lusoria has esophageal compression by?
a) Aberrant right subclavian artery
b) Left brachiocephalic vein
c) Descending aorta
d) Right pulmonary artery
Explanation: Dysphagia lusoria occurs when an aberrant right subclavian artery arises abnormally and compresses the esophagus posteriorly. The correct answer is a) Aberrant right subclavian artery.
Guessed Question 7
Which structure does the esophagus lie anterior to in posterior mediastinum?
a) Descending thoracic aorta
b) Trachea
c) Left atrium
d) Pulmonary trunk
Explanation: In the posterior mediastinum, the esophagus lies anterior to the descending thoracic aorta and thoracic duct. The correct answer is a) Descending thoracic aorta.
Guessed Question 8
Which clinical investigation best shows left atrial impression on esophagus?
a) Barium swallow
b) Chest X-ray
c) Ultrasound
d) CT thorax
Explanation: A barium swallow clearly shows indentations on esophagus caused by enlarged left atrium, a classic radiological sign. The correct answer is a) Barium swallow.
Guessed Question 9
Which artery provides blood supply to thoracic esophagus?
a) Bronchial arteries
b) Left gastric artery
c) Inferior phrenic arteries
d) All of the above
Explanation: Thoracic esophagus receives blood supply from bronchial arteries, branches of thoracic aorta, and inferior phrenic arteries. The correct answer is d) All of the above.
Guessed Question 10
Posterior mediastinum contains all except?
a) Esophagus
b) Thoracic duct
c) Azygos vein
d) Thymus
Explanation: The thymus is located in anterior mediastinum (prominent in children). Posterior mediastinum includes esophagus, azygos system, thoracic duct, descending aorta. The correct answer is d) Thymus.
Guessed Question 11
Which lymph nodes drain the thoracic esophagus?
a) Posterior mediastinal nodes
b) Paratracheal nodes
c) Left gastric nodes
d) All of the above
Explanation: Thoracic esophagus drains into posterior mediastinal and paratracheal nodes, and through abdominal continuation into left gastric nodes. The correct answer is d) All of the above.
Chapter: Anatomy
Topic: Thorax
Subtopic: Mediastinal Relations of Lungs
Keyword Definitions:
Mediastinal surface of lung: Surface facing the mediastinum, showing impressions of adjacent structures.
Right lung mediastinal relations: Superior vena cava, right atrium, azygos vein, esophagus.
Left lung mediastinal relations: Arch of aorta, left ventricle, thoracic aorta, left subclavian artery.
SVC (Superior Vena Cava): Large vein draining blood from upper half of body into right atrium.
Pulmonary trunk: Major vessel carrying deoxygenated blood from right ventricle to lungs.
Clinical relevance: Knowledge of lung relations is vital in thoracic surgery, mediastinal tumor excision, and radiology.
Lead Question - 2013
Which of the following is related to mediastinal part of right lung?
a) Arch of aorta
b) SVC
c) Pulmonary trunk
d) Left ventricle
Explanation: The mediastinal surface of the right lung is related to the superior vena cava, right atrium, and azygos vein. The left lung is related to arch of aorta and left ventricle. Thus, the correct answer is b) SVC.
Guessed Question 2
Which structure leaves a groove on the mediastinal surface of the left lung?
a) Superior vena cava
b) Arch of aorta
c) Right atrium
d) Azygos vein
Explanation: The arch of aorta produces a large concave impression on the mediastinal surface of the left lung. The correct answer is b) Arch of aorta.
Guessed Question 3
The cardiac impression on the right lung is mainly due to?
a) Right atrium
b) Left ventricle
c) Right ventricle
d) Left atrium
Explanation: The right atrium lies adjacent to the mediastinal surface of the right lung, producing the cardiac impression. The correct answer is a) Right atrium.
Guessed Question 4
The esophagus lies in relation to which lung?
a) Right lung
b) Left lung
c) Both lungs
d) Neither
Explanation: The esophagus runs along the posterior mediastinum and makes an impression on the mediastinal surface of the right lung. The correct answer is a) Right lung.
Guessed Question 5
Which lung shows a groove for azygos vein?
a) Right lung
b) Left lung
c) Both lungs
d) Neither
Explanation: The azygos vein arches over the root of the right lung before entering SVC, leaving a groove on the mediastinal surface of the right lung. The correct answer is a) Right lung.
Guessed Question 6
The pulmonary trunk lies in close relation with?
a) Right lung root
b) Left lung root
c) Both lung roots
d) Neither
Explanation: The pulmonary trunk arises from right ventricle and lies closer to the root of the left lung. The correct answer is b) Left lung root.
Guessed Question 7
Which part of the heart produces impression on the mediastinal surface of the left lung?
a) Right atrium
b) Left ventricle
c) Right ventricle
d) Left atrium
Explanation: The left ventricle lies adjacent to the mediastinal surface of the left lung, producing a cardiac impression. The correct answer is b) Left ventricle.
Guessed Question 8
In CT thorax, a groove on right lung for large vein near its root corresponds to?
a) Superior vena cava
b) Inferior vena cava
c) Right pulmonary vein
d) Azygos vein
Explanation: The superior vena cava lies adjacent to the upper part of the mediastinal surface of right lung, forming a groove. The correct answer is a) Superior vena cava.
Guessed Question 9
Which great vessel does NOT leave an impression on the right lung?
a) Superior vena cava
b) Azygos vein
c) Inferior vena cava
d) Arch of aorta
Explanation: The arch of aorta lies in relation to the left lung and does not leave an impression on the right lung. The correct answer is d) Arch of aorta.
Guessed Question 10
During right pneumonectomy, which mediastinal relation must be preserved to prevent venous obstruction?
a) Azygos vein
b) Thoracic duct
c) Arch of aorta
d) Left ventricle
Explanation: The azygos vein arches over the right lung root and drains into SVC. Damage during surgery can cause venous obstruction and swelling of upper body. The correct answer is a) Azygos vein.
Guessed Question 11
Which clinical feature is expected in tumor compressing SVC related to right lung?
a) Dysphagia
b) Hoarseness of voice
c) Swelling of face and upper limb
d) Hemoptysis
Explanation: Superior vena cava obstruction causes venous congestion of face, neck, and upper limb, leading to swelling and dilated veins. The correct answer is c) Swelling of face and upper limb.
Chapter: Anatomy
Topic: Thorax
Subtopic: Heart Surfaces and Relations
Keyword Definitions:
Base of heart: Posterior surface formed mainly by left atrium, partly by right atrium.
Atrium: Upper chamber of the heart; right atrium receives venous blood, left atrium receives pulmonary venous blood.
Ventricle: Lower chamber of the heart; right ventricle pumps to lungs, left ventricle to systemic circulation.
Posterior mediastinum: Part of thorax behind the heart containing esophagus and great vessels.
Clinical relevance: Knowledge of cardiac surfaces is essential in imaging, echocardiography, and surgical approaches.
Lead Question - 2013
Posterior surface of heart is formed by -
a) RA
b) LA
c) LV
d) RV
Explanation: The posterior surface of the heart, also called the base, is formed mainly by the left atrium, which receives pulmonary veins. The right atrium contributes slightly. Thus, the correct answer is b) LA.
Guessed Question 2
The diaphragmatic surface of the heart is formed mainly by?
a) Right atrium
b) Right ventricle
c) Left ventricle
d) Left atrium
Explanation: The diaphragmatic surface of the heart rests on the central tendon of the diaphragm and is formed mainly by the left ventricle with a small contribution from the right ventricle. The correct answer is c) Left ventricle.
Guessed Question 3
The right border of the heart is formed by?
a) Right atrium
b) Right ventricle
c) Left atrium
d) Left ventricle
Explanation: The right border of the heart seen on chest X-ray is formed by the right atrium, which receives venous blood from the SVC and IVC. The correct answer is a) Right atrium.
Guessed Question 4
The apex of the heart is formed by?
a) Right ventricle
b) Left ventricle
c) Left atrium
d) Right atrium
Explanation: The apex beat, palpable in the left 5th intercostal space, is formed by the tip of the left ventricle. The correct answer is b) Left ventricle.
Guessed Question 5
Which chamber of the heart lies closest to the esophagus?
a) Right atrium
b) Left atrium
c) Right ventricle
d) Left ventricle
Explanation: The left atrium forms the posterior surface of the heart and lies directly in front of the esophagus in the posterior mediastinum. The correct answer is b) Left atrium.
Guessed Question 6
On a lateral chest X-ray, the posterior border of the heart is formed by?
a) Right ventricle
b) Left ventricle
c) Left atrium
d) Right atrium
Explanation: In lateral chest radiographs, the posterior border of the heart is formed by the left atrium and left ventricle. The correct answer is c) Left atrium.
Guessed Question 7
Which chamber enlargement causes dysphagia by compressing esophagus?
a) Right atrium
b) Left atrium
c) Left ventricle
d) Right ventricle
Explanation: Enlargement of the left atrium can compress the esophagus, leading to dysphagia. This is often seen in mitral stenosis. The correct answer is b) Left atrium.
Guessed Question 8
The anterior surface of the heart is mainly formed by?
a) Left atrium
b) Right ventricle
c) Left ventricle
d) Right atrium
Explanation: The sternocostal or anterior surface of the heart is formed mainly by the right ventricle. The correct answer is b) Right ventricle.
Guessed Question 9
Which chamber of the heart contributes most to the left border in chest X-ray?
a) Right ventricle
b) Left ventricle
c) Right atrium
d) Left atrium
Explanation: The left border of the cardiac shadow on chest X-ray is formed mainly by the left ventricle. The correct answer is b) Left ventricle.
Guessed Question 10
Which cardiac chamber is most posterior in location?
a) Right atrium
b) Right ventricle
c) Left atrium
d) Left ventricle
Explanation: The left atrium forms the base of the heart and is the most posteriorly placed chamber. The correct answer is c) Left atrium.
Guessed Question 11
Atrial fibrillation commonly originates due to abnormal conduction from which heart chamber?
a) Right atrium
b) Left atrium
c) Right ventricle
d) Left ventricle
Explanation: Atrial fibrillation often originates from ectopic foci near the openings of pulmonary veins in the left atrium. The correct answer is b) Left atrium.
Chapter: Anatomy
Topic: Thorax
Subtopic: Heart Surfaces and Borders
Keyword Definitions:
Sternocostal (anterior) surface: Surface of the heart facing sternum and ribs, mainly right ventricle.
Atrium: Right atrium receives systemic venous blood, left atrium receives pulmonary venous blood.
Ventricle: Right ventricle pumps blood to pulmonary circulation, left ventricle to systemic circulation.
Auricle: Small muscular pouch projecting from atrium, increases volume capacity.
Clinical relevance: Knowledge of heart surfaces is essential for interpretation of X-rays, echocardiograms, and cardiac interventions.
Lead Question - 2013
Anterosuperior sternal part of heart is made up of?
a) Right atrium and auricle
b) Left atrium
c) Left ventricle
d) Right ventricle
Explanation: The sternocostal (anterior) surface of the heart is mainly formed by the right ventricle, with a small contribution from the right atrium and auricle. Thus, the correct answer is d) Right ventricle.
Guessed Question 2
The diaphragmatic surface of the heart is formed primarily by?
a) Left atrium
b) Left ventricle
c) Right atrium
d) Right ventricle
Explanation: The diaphragmatic surface of the heart rests on the diaphragm and is formed mainly by the left ventricle with some contribution from the right ventricle. The correct answer is b) Left ventricle.
Guessed Question 3
The posterior surface of the heart is mainly formed by?
a) Left atrium
b) Right atrium
c) Left ventricle
d) Right ventricle
Explanation: The posterior surface (base) of the heart is formed mainly by the left atrium, with minor contribution from the right atrium. The correct answer is a) Left atrium.
Guessed Question 4
The apex of the heart is contributed by?
a) Right ventricle
b) Left ventricle
c) Right atrium
d) Left atrium
Explanation: The apex beat, felt in the left 5th intercostal space, is formed by the left ventricle. The correct answer is b) Left ventricle.
Guessed Question 5
The right border of the heart seen on chest X-ray is formed by?
a) Right atrium
b) Left atrium
c) Right ventricle
d) Left ventricle
Explanation: The right border of the cardiac shadow in a chest X-ray is formed by the right atrium. The correct answer is a) Right atrium.
Guessed Question 6
The left border of the heart seen on chest X-ray is formed by?
a) Right ventricle
b) Left ventricle
c) Right atrium
d) Left atrium
Explanation: The left border of the cardiac shadow on chest radiograph is formed mainly by the left ventricle, with a small contribution by the left auricle. The correct answer is b) Left ventricle.
Guessed Question 7
The inferior border of the heart is formed mainly by?
a) Right ventricle
b) Left ventricle
c) Right atrium
d) Left atrium
Explanation: The inferior (acute) border of the heart is formed largely by the right ventricle with a small contribution by the left ventricle. The correct answer is a) Right ventricle.
Guessed Question 8
Enlargement of which chamber causes a prominent bulge in the right border of cardiac shadow?
a) Left ventricle
b) Left atrium
c) Right ventricle
d) Right atrium
Explanation: Right atrial enlargement causes prominence of the right heart border on X-ray. The correct answer is d) Right atrium.
Guessed Question 9
Enlargement of which chamber is most likely to compress the esophagus?
a) Right atrium
b) Right ventricle
c) Left atrium
d) Left ventricle
Explanation: The left atrium lies immediately in front of the esophagus, and its enlargement can cause dysphagia. The correct answer is c) Left atrium.
Guessed Question 10
The anterior surface of the heart is clinically important because?
a) It is mainly formed by right ventricle, site of trauma injury
b) It is formed by left ventricle, site of infarction
c) It is formed by atria only
d) It is protected by esophagus
Explanation: The anterior surface is mainly formed by the right ventricle, which is vulnerable to trauma and penetrating injuries. The correct answer is a) It is mainly formed by right ventricle, site of trauma injury.
Guessed Question 11
The posterior surface of the heart is closely related to?
a) Trachea
b) Esophagus
c) Sternum
d) Diaphragm
Explanation: The posterior surface of the heart is closely related to the esophagus, which lies in the posterior mediastinum. The correct answer is b) Esophagus.
Chapter: Anatomy
Topic: Thorax
Subtopic: Anterior Relations of Heart
Keyword Definitions:
Sternocostal surface: The anterior surface of the heart facing the sternum and ribs.
Right ventricle: Chamber that pumps deoxygenated blood into the pulmonary trunk, forms anterior surface.
Left ventricle: Pumps oxygenated blood to systemic circulation, forms apex and left border.
Right atrium: Receives venous blood from SVC, IVC, and coronary sinus, forms right border.
Left atrium: Receives pulmonary veins, forms posterior surface, closely related to esophagus.
Clinical relevance: Knowledge of surfaces helps in trauma assessment, imaging, and surgical approaches.
Lead Question - 2013
Posterior to sternum is?
a) Left atrium
b) Left ventricle
c) Right atrium
d) Right ventricle
Explanation: The sternocostal (anterior) surface of the heart lies directly behind the sternum and is formed mainly by the right ventricle, with a small contribution from the right atrium. Thus, the correct answer is d) Right ventricle.
Guessed Question 2
The posterior surface of the heart is formed by?
a) Right ventricle
b) Left atrium
c) Right atrium
d) Left ventricle
Explanation: The posterior surface or base of the heart is formed mainly by the left atrium, which is in relation to the esophagus. The correct answer is b) Left atrium.
Guessed Question 3
The apex of the heart is contributed by?
a) Right ventricle
b) Left ventricle
c) Right atrium
d) Left atrium
Explanation: The apex beat palpable in the left 5th intercostal space is formed by the left ventricle. The correct answer is b) Left ventricle.
Guessed Question 4
The right border of the heart is mainly formed by?
a) Right atrium
b) Left atrium
c) Right ventricle
d) Left ventricle
Explanation: The right atrium forms the right cardiac border visible on chest X-ray. The correct answer is a) Right atrium.
Guessed Question 5
The left border of the heart in chest X-ray is formed by?
a) Left ventricle
b) Right ventricle
c) Right atrium
d) Right ventricle and atrium
Explanation: The left border of the cardiac shadow is formed mainly by the left ventricle, with a small contribution from the left auricle. The correct answer is a) Left ventricle.
Guessed Question 6
The inferior border of the heart is formed largely by?
a) Left ventricle
b) Right ventricle
c) Right atrium
d) Left atrium
Explanation: The inferior border or diaphragmatic surface of the heart is formed largely by the right ventricle with a small contribution from the left ventricle. The correct answer is b) Right ventricle.
Guessed Question 7
Which chamber is most closely related to the esophagus?
a) Left atrium
b) Left ventricle
c) Right ventricle
d) Right atrium
Explanation: The left atrium forms the posterior surface of the heart and lies directly in front of the esophagus. Enlargement of LA can cause dysphagia. The correct answer is a) Left atrium.
Guessed Question 8
The anterior surface of the heart is clinically significant because?
a) It is mostly formed by right ventricle, vulnerable to trauma
b) It is mostly formed by left atrium, related to esophagus
c) It is mostly formed by left ventricle, vulnerable to infarction
d) It is protected by the spine
Explanation: The anterior surface is mainly formed by the right ventricle, which is the most vulnerable chamber in penetrating chest trauma. The correct answer is a) It is mostly formed by right ventricle, vulnerable to trauma.
Guessed Question 9
In mitral stenosis, which chamber enlarges most prominently?
a) Right ventricle
b) Left atrium
c) Right atrium
d) Left ventricle
Explanation: Mitral stenosis causes obstruction to left atrial emptying, leading to marked enlargement of the left atrium. The correct answer is b) Left atrium.
Guessed Question 10
Which chamber is most anterior in location?
a) Right ventricle
b) Left atrium
c) Left ventricle
d) Right atrium
Explanation: The right ventricle lies directly behind the sternum and is the most anterior chamber of the heart. The correct answer is a) Right ventricle.
Guessed Question 11
Which chamber is most posterior in location?
a) Right atrium
b) Left atrium
c) Left ventricle
d) Right ventricle
Explanation: The left atrium is the most posterior chamber, lying directly in front of the esophagus in the posterior mediastinum. The correct answer is b) Left atrium.
Chapter: Anatomy
Topic: Thorax
Subtopic: Trachea and Bronchi
Keyword Definitions:
Right bronchus: Primary bronchus supplying right lung, shorter, wider, and more vertical than left.
Left bronchus: Narrower, longer, and more oblique, passes below the arch of aorta.
Carina: Ridge at tracheal bifurcation, highly sensitive, directs airflow.
Aspiration: Foreign bodies are more likely to lodge in right bronchus due to its alignment.
Bronchoscopy: Clinical procedure to visualize and manage airway pathologies.
Clinical relevance: Bronchial anatomy is crucial for intubation, aspiration, and radiology interpretation.
Lead Question - 2013
Not true about right bronchus
a) Shorter
b) Wider
c) More horizontal
d) In the line of trachea
Explanation: The right bronchus is shorter, wider, and more vertical, aligning with the trachea, making it a common site for aspirated foreign bodies. The statement “more horizontal” is false. Thus, the correct answer is c) More horizontal.
Guessed Question 2
Which bronchus is more prone to foreign body aspiration?
a) Left
b) Right
c) Both equally
d) Neither
Explanation: The right bronchus is wider, shorter, and more vertical, making it the commonest site for aspirated objects in adults and children. The correct answer is b) Right.
Guessed Question 3
Carina is located at which vertebral level?
a) T2
b) T4/T5
c) T6
d) T8
Explanation: The trachea bifurcates at the sternal angle (angle of Louis) corresponding to T4/T5 vertebral level, where the carina is located. The correct answer is b) T4/T5.
Guessed Question 4
The left bronchus passes beneath which vascular structure?
a) Aortic arch
b) Pulmonary trunk
c) SVC
d) Right atrium
Explanation: The left main bronchus runs under the arch of aorta and in front of the esophagus, making it longer and more oblique than the right bronchus. The correct answer is a) Aortic arch.
Guessed Question 5
In bronchoscopy, which structure indicates the division of bronchi?
a) Hilum
b) Carina
c) Trachealis muscle
d) Pulmonary ligament
Explanation: The carina is a ridge inside the trachea at the bifurcation into right and left bronchi. It is a key landmark in bronchoscopy and highly sensitive to stimulation. The correct answer is b) Carina.
Guessed Question 6
Which bronchus is longer?
a) Left
b) Right
c) Both equal
d) Depends on respiration
Explanation: The left main bronchus is longer (about 5 cm) compared to the right (2.5 cm), as it needs to cross structures like the aorta to reach the left lung. The correct answer is a) Left.
Guessed Question 7
A child aspirates a peanut. Where is it most likely to lodge?
a) Left main bronchus
b) Right main bronchus
c) Larynx
d) Esophagus
Explanation: Due to its wider, shorter, and more vertical orientation, the right bronchus is the most common site for foreign body aspiration. The correct answer is b) Right main bronchus.
Guessed Question 8
The right upper lobe bronchus branches off before?
a) Carina
b) Hilum
c) Right pulmonary artery
d) Right atrium
Explanation: The right upper lobe bronchus arises before the hilum of the right lung and above the right pulmonary artery, making the right bronchus eparterial. The correct answer is c) Right pulmonary artery.
Guessed Question 9
The left bronchus in relation to pulmonary artery is termed?
a) Eparterial
b) Hyparterial
c) Subarterial
d) Supraarterial
Explanation: The left bronchus lies inferior to the left pulmonary artery, hence it is termed hyparterial, while the right upper bronchus is eparterial. The correct answer is b) Hyparterial.
Guessed Question 10
During intubation, if tube enters right bronchus, what occurs?
a) Both lungs ventilated
b) Only right lung ventilated
c) Only left lung ventilated
d) No ventilation
Explanation: If the endotracheal tube goes too deep, it often enters the right bronchus, ventilating only the right lung, leading to hypoxia and left lung collapse. The correct answer is b) Only right lung ventilated.
Guessed Question 11
Which bronchus is more oblique in direction?
a) Right
b) Left
c) Both
d) Neither
Explanation: The left main bronchus is longer and runs more obliquely to reach the left lung, unlike the right bronchus which is more vertical. The correct answer is b) Left.
Chapter: Anatomy
Topic: Thorax
Subtopic: Thoracic Duct
Keyword Definitions:
Thoracic duct: Main lymphatic channel draining most of the body except right upper quadrant.
Right lymphatic duct: Drains right upper limb, right thorax, and right head and neck.
Cisterna chyli: Dilated sac at L1–L2 origin of thoracic duct.
Mediastinum: Central thoracic compartment containing heart, vessels, and ducts.
Lymphatic drainage: Essential for immune surveillance and fluid balance.
Clinical relevance: Thoracic duct injury can cause chylothorax after surgery or trauma.
Lead Question - 2013
Thoracic duct does not drains ?
a) Right upper part of body
b) Left upper part of body
c) Right lower part of body
d) Left lower part of body
Explanation: The thoracic duct drains lymph from both lower limbs, abdomen, left thorax, left upper limb, and left side of head and neck. It does not drain the right upper quadrant of the body, which is drained by the right lymphatic duct. Correct answer is a) Right upper part of body.
Guessed Question 2
Thoracic duct opens into?
a) Right venous angle
b) Left venous angle
c) Right atrium
d) Superior vena cava
Explanation: The thoracic duct terminates at the left venous angle, the junction of the left internal jugular and left subclavian veins, returning lymph to venous circulation. Correct answer is b) Left venous angle.
Guessed Question 3
Origin of thoracic duct is from?
a) Cisterna chyli
b) Right lymphatic duct
c) Thoracoabdominal artery
d) Azygous vein
Explanation: The thoracic duct begins at the cisterna chyli, a dilated sac at the level of L1–L2, formed by intestinal and lumbar lymph trunks. Correct answer is a) Cisterna chyli.
Guessed Question 4
Which structure lies to the right of thoracic duct in thorax?
a) Descending aorta
b) Azygous vein
c) Esophagus
d) Left subclavian vein
Explanation: In most of the thoracic course, the thoracic duct is flanked by the azygous vein on the right and descending aorta on the left, with the esophagus anterior. Correct answer is b) Azygous vein.
Guessed Question 5
Injury to thoracic duct causes?
a) Pneumothorax
b) Chylothorax
c) Hemothorax
d) Hydrothorax
Explanation: Damage to the thoracic duct during surgery or trauma leads to leakage of lymph (chyle) into the pleural cavity, producing chylothorax, which causes respiratory distress and fluid loss. Correct answer is b) Chylothorax.
Guessed Question 6
Thoracic duct passes through diaphragm via?
a) Caval opening
b) Esophageal opening
c) Aortic opening
d) Foramen ovale
Explanation: The thoracic duct enters thorax through the aortic opening of the diaphragm, along with the descending aorta and azygous vein, at T12 level. Correct answer is c) Aortic opening.
Guessed Question 7
Which lymphatic trunk drains lower limb?
a) Jugular trunk
b) Subclavian trunk
c) Lumbar trunk
d) Bronchomediastinal trunk
Explanation: The lumbar lymphatic trunks drain the lower limbs, pelvis, and kidneys, and they join to form the cisterna chyli, the origin of thoracic duct. Correct answer is c) Lumbar trunk.
Guessed Question 8
Thoracic duct lies in which mediastinum for most of its course?
a) Anterior
b) Middle
c) Posterior
d) Superior
Explanation: The thoracic duct ascends through the posterior mediastinum between the aorta, azygous vein, and esophagus, before arching to the left in the superior mediastinum. Correct answer is c) Posterior.
Guessed Question 9
Thoracic duct arches to left at the level of?
a) T2
b) T4–T5
c) T8
d) T10
Explanation: The thoracic duct crosses from right to left side at the T4–T5 vertebral level, behind the esophagus, before its termination at the left venous angle. Correct answer is b) T4–T5.
Guessed Question 10
Which of the following is not drained by thoracic duct?
a) Abdomen
b) Both lower limbs
c) Left head and neck
d) Right upper limb
Explanation: Right upper limb drains into right lymphatic duct, not thoracic duct. The thoracic duct drains abdomen, lower limbs, left head and neck, left thorax, and left upper limb. Correct answer is d) Right upper limb.
Guessed Question 11
During esophageal carcinoma surgery, thoracic duct is at risk in which region?
a) Posterior mediastinum
b) Anterior mediastinum
c) Pericardial sac
d) Caval hiatus
Explanation: Esophageal mobilization in posterior mediastinum places thoracic duct at risk of injury, potentially causing postoperative chylothorax. Correct answer is a) Posterior mediastinum.
Chapter: Anatomy
Topic: Thorax
Subtopic: Intercostal Arteries
Keyword Definitions:
Intercostal arteries: Arteries supplying muscles, skin, and parietal pleura of thoracic wall.
Posterior intercostal arteries: Branches mainly from thoracic aorta, except upper two from superior intercostal artery.
Anterior intercostal arteries: Branches of internal thoracic (mammary) artery and musculophrenic artery.
Superior intercostal artery: Branch of costocervical trunk from subclavian artery, supplies 1st and 2nd spaces.
Collateral circulation: Network formed between anterior and posterior intercostal arteries.
Clinical relevance: Important in thoracotomy, rib fractures, and chest tube insertion.
Lead Question - 2013
Upper two posterior intercostal arteries arise from ?
a) Aorta
b) Superior intercostal artery
c) Internal mammary artery
d) Bronchial artery
Explanation: The first and second posterior intercostal arteries originate from the superior intercostal artery, a branch of the costocervical trunk of the subclavian artery. The remaining posterior intercostal arteries arise from thoracic aorta. Correct answer is b) Superior intercostal artery.
Guessed Question 2
Most posterior intercostal arteries arise from?
a) Aorta
b) Subclavian artery
c) Internal thoracic artery
d) Vertebral artery
Explanation: Except for the first two, posterior intercostal arteries (3rd–11th) arise directly from the thoracic aorta, ensuring supply to thoracic wall. Correct answer is a) Aorta.
Guessed Question 3
Anterior intercostal arteries are branches of?
a) Thoracic aorta
b) Internal thoracic artery
c) Superior intercostal artery
d) Subclavian vein
Explanation: The anterior intercostal arteries arise from the internal thoracic artery in the upper spaces and from musculophrenic artery in lower spaces. Correct answer is b) Internal thoracic artery.
Guessed Question 4
Which vessel supplies the first two intercostal spaces posteriorly?
a) Thoracic aorta
b) Superior intercostal artery
c) Musculophrenic artery
d) Internal thoracic artery
Explanation: The superior intercostal artery, a branch of costocervical trunk from subclavian, supplies the first two posterior intercostal spaces. Correct answer is b) Superior intercostal artery.
Guessed Question 5
Intercostal arteries lie between?
a) External and internal intercostals
b) Internal and innermost intercostals
c) Pleura and innermost intercostals
d) Skin and external intercostals
Explanation: The intercostal neurovascular bundle (vein, artery, nerve) runs in the costal groove between internal and innermost intercostal muscles. Correct answer is b) Internal and innermost intercostals.
Guessed Question 6
The costocervical trunk is a branch of?
a) Aorta
b) Subclavian artery
c) Internal thoracic artery
d) Axillary artery
Explanation: The costocervical trunk is a branch of the subclavian artery that gives rise to the superior intercostal artery and deep cervical artery. Correct answer is b) Subclavian artery.
Guessed Question 7
The largest branch of posterior intercostal artery is?
a) Dorsal branch
b) Collateral branch
c) Perforating branch
d) Musculophrenic branch
Explanation: Each posterior intercostal artery gives a large dorsal branch that supplies spinal cord, vertebrae, and muscles of back. Correct answer is a) Dorsal branch.
Guessed Question 8
Internal thoracic artery is a branch of?
a) Aorta
b) Subclavian artery
c) Thoracic aorta
d) Axillary artery
Explanation: The internal thoracic (mammary) artery is a direct branch of the subclavian artery, descending along sternum inside thoracic wall. Correct answer is b) Subclavian artery.
Guessed Question 9
During chest tube insertion, intercostal arteries are avoided by placing tube?
a) Along upper border of rib
b) Along lower border of rib
c) Directly in midrib
d) Over sternum
Explanation: The intercostal neurovascular bundle runs along the inferior border of ribs, so procedures like chest tube insertion are performed just above the upper border of rib. Correct answer is a) Along upper border of rib.
Guessed Question 10
Anterior intercostal arteries for lower spaces arise from?
a) Musculophrenic artery
b) Internal thoracic artery
c) Aorta
d) Superior intercostal artery
Explanation: The musculophrenic artery, a terminal branch of internal thoracic artery, supplies anterior intercostal arteries for lower intercostal spaces. Correct answer is a) Musculophrenic artery.
Guessed Question 11
Intercostal space is drained by which veins posteriorly?
a) Azygos and hemiazygos system
b) Pulmonary veins
c) Vertebral veins
d) Coronary sinus
Explanation: Posterior intercostal veins drain into the azygos vein on right and hemiazygos/accessory hemiazygos veins on left, ultimately into superior vena cava. Correct answer is a) Azygos and hemiazygos system.
Chapter: Anatomy
Topic: Thorax
Subtopic: Anterior Intercostal Arteries
Keyword Definitions:
Intercostal arteries: Arteries that supply the thoracic wall including muscles, skin, and parietal pleura.
Anterior intercostal arteries: Branches of internal thoracic and musculophrenic arteries, present in upper nine intercostal spaces.
Posterior intercostal arteries: Branches of thoracic aorta (except 1st and 2nd from superior intercostal artery).
Internal thoracic artery: Branch of subclavian artery, gives anterior intercostal and musculophrenic arteries.
Musculophrenic artery: Terminal branch of internal thoracic artery, supplies lower anterior intercostal arteries.
Azygos system: Venous system draining posterior intercostal veins into SVC.
Clinical relevance: Important in chest surgeries, flap reconstruction, and thoracostomies.
Lead Question - 2013
True about anterior intercostal artery ?
a) Present in 1st to 11th intercostal space
b) Each intercostal space has two anterior intercostal arteries
c) Branch of internal thoracic artery
d) Branch of aorta
Explanation: Anterior intercostal arteries are branches of the internal thoracic and musculophrenic arteries. They are present only in upper nine intercostal spaces, with two arteries per space. They do not arise from the aorta. Correct answers are b) Each intercostal space has two anterior intercostal arteries and c) Branch of internal thoracic artery.
Guessed Question 2
Anterior intercostal arteries are absent in which spaces?
a) 1st and 2nd
b) 9th to 11th
c) 7th and 8th
d) Only 11th
Explanation: Anterior intercostal arteries are present in the first nine spaces. They are absent in the 10th and 11th intercostal spaces because these are “floating ribs” with no anterior articulation. Correct answer is b) 9th to 11th.
Guessed Question 3
Which artery gives rise to anterior intercostal arteries of upper six spaces?
a) Musculophrenic artery
b) Thoracic aorta
c) Internal thoracic artery
d) Superior intercostal artery
Explanation: The internal thoracic artery, a branch of subclavian, gives off anterior intercostal arteries for the first six spaces before dividing into musculophrenic and superior epigastric arteries. Correct answer is c) Internal thoracic artery.
Guessed Question 4
Anterior intercostal arteries of 7th–9th spaces are branches of?
a) Internal thoracic artery
b) Musculophrenic artery
c) Aorta
d) Superior intercostal artery
Explanation: The musculophrenic artery, a terminal branch of internal thoracic artery, supplies the anterior intercostal arteries of the 7th–9th intercostal spaces. Correct answer is b) Musculophrenic artery.
Guessed Question 5
Which intercostal spaces have both anterior and posterior intercostal arteries?
a) 1st–9th
b) 1st–11th
c) Only upper six
d) Only lower six
Explanation: Spaces 1st–9th have both anterior and posterior intercostal arteries. The 10th and 11th spaces have only posterior intercostal arteries due to absence of anterior ends. Correct answer is a) 1st–9th.
Guessed Question 6
Anterior intercostal arteries anastomose with?
a) Coronary arteries
b) Posterior intercostal arteries
c) Bronchial arteries
d) Phrenic arteries
Explanation: Anterior intercostal arteries anastomose with posterior intercostal arteries in each intercostal space, ensuring collateral circulation in thoracic wall. Correct answer is b) Posterior intercostal arteries.
Guessed Question 7
Internal thoracic artery terminates as?
a) Superior epigastric and musculophrenic arteries
b) Anterior intercostal arteries
c) Bronchial and phrenic arteries
d) Superior thyroid and vertebral arteries
Explanation: The internal thoracic artery ends by dividing into musculophrenic and superior epigastric arteries at the level of 6th intercostal space. Correct answer is a) Superior epigastric and musculophrenic arteries.
Guessed Question 8
During CABG (coronary artery bypass graft), which artery is most commonly used?
a) Internal thoracic artery
b) Radial artery
c) Femoral artery
d) Inferior epigastric artery
Explanation: The internal thoracic artery is commonly harvested for CABG due to its excellent long-term patency rates. Correct answer is a) Internal thoracic artery.
Guessed Question 9
Which nerve accompanies anterior intercostal arteries?
a) Vagus nerve
b) Intercostal nerve
c) Phrenic nerve
d) Sympathetic chain
Explanation: Anterior intercostal arteries run along with intercostal nerves and veins in the costal groove between internal and innermost intercostal muscles. Correct answer is b) Intercostal nerve.
Guessed Question 10
Which artery supplies anterior intercostal arteries in upper six spaces?
a) Internal thoracic artery
b) Aorta
c) Superior intercostal artery
d) Axillary artery
Explanation: The internal thoracic artery supplies anterior intercostal arteries for the upper six intercostal spaces before bifurcating. Correct answer is a) Internal thoracic artery.
Guessed Question 11
Anterior intercostal arteries are clinically important in?
a) Drainage of pleural effusion
b) CABG grafting and chest wall surgeries
c) Tracheostomy
d) Vertebral surgery
Explanation: Anterior intercostal arteries are vital in thoracic wall reconstruction, mastectomy, and as collaterals in coronary bypass grafting using internal thoracic artery. Correct answer is b) CABG grafting and chest wall surgeries.