Thoracic A

Question 1

Question 11 of 328 A 23 year old man is stabbed in the chest approximately 10cm below the right nipple. In the emergency department a abdominal ultrasound scan shows a large amount of intraperitoneal blood. Which of the following statements rela

Answer 1

The quadrate lobe is contained within the functional right lobeThe right lobe of the liver is the most likely site of injury. Therefore the answer is B as the quadrate lobe is functionally part of the left lobe of the liver. The liver is largely covered in peritoneum. Posteriorly there is an area devoid of peritoneum (the bare area of the liver). The right lobe of the liver has the largest bare area (ans is larger thant the left lobe).

Question 2

Question 13 of 328 A 72 year old man presents with haemoptysis and undergoes a bronchoscopy. The carina is noted to be widened. At which level does the trachea bifurcate? A. T3 B. T5 C. T7 D. T2 E. T8

Answer 2

T5The trachea bifurcates at the level of the fifth thoracic vertebra. Or the sixth in tall subjects.

Question 3

Question 14 of 328 A 23 year old man is injured during a game of rugby. He suffers a fracture of the distal third of his clavicle, it is a compound fracture and there is evidence of arterial haemorrhage. Which of the following vessels is most li

Answer 3

Thoracoacromial artery

Question 4

Question 36 of 328 Which structure is least likely to be found at the level of the sternal angle? A. Left brachiocephalic vein B. Intervertebral discs T4-T5 C. Start of aortic arch D. 2nd pair of costal cartilages E. Bifurcation

Answer 4

The left brachiocephalic vein lies posterior to the manubrium, at the level of its upper border. The sternal angle refers to the transition between manubrium and sternum and therefore will not include the left brachiocephalic vein.

Question 5

Question 52 of 328 A 43 year old man is reviewed in the clinic following a cardiac operation. A chest x-ray is performed and a circular radio-opaque structure is noted medial to the 4th interspace on the left. Which of the following procedures is

Answer 5

Mitral valve replacement with metallic valve

Question 6

Question 59 of 328 A 23 year old man is shot in the chest during a robbery. The left lung is lacerated and is bleeding. An emergency thoracotomy is performed. The surgeons place a clamp over the hilum of the left lung. Which of the following str

Answer 6

The phrenic nerve lies anteriorly at this point. The vagus passes anteriorly and then arches backwards immediately superior to the root of the left bronchus, giving off the recurrent laryngeal nerve as it does so.

Question 7

Question 66 of 328 Which of the following statements relating to the vertebral column is false? A. There are 7 cervical vertebrae B. The cervical and lumbar lordosis are secondary curves developing after birth due to change in shape of the in

Answer 7

The spinous process is formed by 2 laminae posteriorly.

Question 8

Question 68 of 328 A 73 year old man undergoes a sub total oesophagectomy with anastomosis of the stomach to the cervical oesophagus. Which vessel will be primarily responsible for the arterial supply to the oesophageal portion of the anastomosis

Answer 8

Inferior thyroid arteryThe cervical oesophagus is supplied by the inferior thyroid artery. The thoracic oesophagus (removed in this case) is supplied by direct branches from the thoracic aorta.

Question 9

Question 75 of 328 During the repair of an atrial septal defect the surgeons note that blood starts to leak from the coronary sinus. Which structure forms the largest tributary of the coronary sinus? A. Thesbian veins B. Great cardiac vein

Answer 9

The great cardiac vein runs in the anterior interventricular groove, and is the largest tributary of the coronary sinus. The Thesbian veins drain into the heart directly.

Question 10

Question 76 of 328 Which of the following vessels provides the greatest contribution to the arterial supply of the breast? A. External mammary artery B. Thoracoacromial artery C. Internal mammary artery D. Lateral thoracic artery E.

Answer 10

Internal mammary artery60% of the arterial supply to the breast is derived from the internal mammary artery. The external mammary and lateral thoracic arteries also make a significant (but lesser) contribution. This is of importance clinically in performing reduction mammoplasty procedures.

Question 11

Question 86 of 328 A man is stabbed in the chest to the right of the manubriosternal angle. Which structure is least likely to be injured in this case? A. Aortic arch B. The trachea C. Right phrenic nerve D. Right recurrent laryngea

Answer 11

The right recurrent laryngeal nerve branches off the right vagus more proximally and arches posteriorly round the subclavian artery. So of the structures given it is the least likely to be injured

Question 12

Question 88 of 328 Which of the following types of epithelium lines the lumenal surface of the normal oesophagus? A. Non keratinised stratified squamous epithelium B. Ciliated columnar epithelium C. Keratinised stratified squamous epit

Answer 12

Non keratinised stratified squamous epitheliumThe oesphagus is lined by non keratinised stratified squamous epithelium. Changes to glandular type epithelium occur as part of metaplastic processes in reflux.

Question 13

Question 95 of 328 The oesophagus is constricted at the following levels apart from: A. Cricoid cartilage B. Arch of the aorta C. Lower oesophageal sphincter D. Left main stem bronchus E. Diaphragmatic hiatus

Answer 13

Lower oesophageal sphincterThe oesophagus is not constricted at the level of the lower oesophageal sphincter.

Question 14

Question 98 of 328 Which of the following structures separates the intervertebral disks from the spinal cord? A. Anterior longitudinal ligament B. Posterior longitudinal ligament C. Supraspinous ligament D. Interspinous ligament E. L

Answer 14

The posterior longitudinal ligament overlies the posterior aspect of the vertebral bodies. It also overlies the posterior aspect of the intervertebral disks.

Question 15

Question 100 of 328 A 23 year old man is due to undergo a mitral valve repair for mitral regurgitation. Which of the following is a feature of the mitral valve? A. Its closure is marked by the first heart sound B. It has two anterior cusps

Answer 15

Its closure is marked by the first heart soundThe mitral valve is best auscultated over the cardiac apex, where its closure marks the first heart sound. It has only two cusps. These are attached to chordae tendinae which themselves are linked to the wall of the ventricle by the papillary muscles.

Question 16

Question 108 of 328 Which of the following overlies the outer muscular layer of the intrathoracic oesophagus? A. Serosa B. Meissners plexus C. Auerbach’s plexus D. Loose connective tissue E. None of the above

Answer 16

Loose connective tissueThe oesophagus has no serosal covering and hence holds sutures poorly. The Auerbach’s and Meissner’s nerve plexuses lie in between the longitudinal and circular muscle layers and submucosally. The sub mucosal location of the Meissner’s nerve plexus facilitates its sensory role.

Question 17

Question 110 of 328 At which of the following spinal levels does the oesophagus pass through the diaphragm into the abdominal cavity? A. L2 B. L1 C. T10 D. T5 E. T12

Answer 17

T10The oesophagus passes into the abdomen at T10

Question 18

Question 132 of 328 A 56 year old lady with metastatic breast cancer develops an oestolytic deposit in the proximal femur. One morning whilst getting out of bed she notices severe groin pain. X-rays show that the lesser trochanter has been avulsed. W

Answer 18

The psoas major inserts into the lesser trochanter and contracts when raising the trunk from the supine position. When oestolytic lesions are present in the femur the lesser trochanter may be avulsed.

Question 19

Question 141 of 328 A 42 year old lady has had an axillary node clearance for breast malignancy. Post operatively she reports weakness of the shoulder. She is unable to push herself forwards from a wall with the right arm and the scapula is pushed ou

Answer 19

Long thoracic nerveTheme from January 2012 and 2009 ExamThe patient has a winged scapula caused by damage to the long thoracic nerve (C5,6,7) during surgery. The long thoracic nerve innervates serratus anterior. Serratus anterior causes pushing out of the scapula during a punch.NB winging of the scapular laterally may indicate trapezius muscle weakness. Innervated by the spinal accessory nerve.

Question 20

Question 143 of 328 How many fissures are present within the right lung? A. One B. Three C. Two D. Four E. Five

Answer 20

2The right lung has an oblique and horizontal fissure. The upper oblique fissure separates the inferior from the middle and upper lobes. The short horizontal fissure separates the superior and middle lobes.

Question 21

Question 159 of 328 From which structure is the central tendon of the diaphragm derived? A. Septum transversum B. Pleuroperitoneal folds C. Diaphragmatic crura D. Dorsal mesocardium E. Oropharyngeal membrane

Answer 21

Septum transversumThe septum transversum is a thick ridge of mesodermal tissue in the developing embryo that separates the thoracic and abdominal cavities and forms the central tendon of the diaphragm.

Question 22

Question 186 of 328 A 23 year old man is admitted with a suspected ureteric colic. A KUB style x-ray is obtained. In which of the following locations is the stone most likely to be visualised? A. The tips of the transverse processes between L2 a

Answer 22

The tips of the transverse processes between L2 and L5The ureter lies anterior to L2 to L5 and stones may be visualised at these points, they may also be identified over the sacro-iliac joints.

Question 23

Question 195 of 328 Which of the following is not contained within the middle mediastinum? A. Main bronchi B. Arch of the azygos vein C. Thoracic duct D. Pericardium E. Aortic root

Answer 23

Thoracic ductThe thoracic duct lies within the posterior and superior mediastinum.

Question 24

Question 197 of 328 Which nerve directly innervates the sinoatrial node? A. Superior cardiac nerve B. Right vagus nerve C. Left vagus nerve D. Inferior cardiac nerve E. None of the above

Answer 24

None of the aboveTheme from September 2011 ExamTheme from September 2012 ExamNo single one of the above nerves is responsible for direct cardiac innervation (which those who have handled the heart surgically will appreciate).The heart receives its nerves from the superficial and deep cardiac plexuses. The cardiac plexuses send small branches to the heart along the major vessels, continuing with the right and left coronary arteries. The vagal efferent fibres emerge from the brainstem in the roots of the vagus and accessory nerves, and run to ganglia in the cardiac plexuses and within the heart itself.The background vagal discharge serves to limit heart rate, and loss of this background vagal tone accounts for the higher resting heart rate seen following cardiac transplant.

Question 25

Question 207 of 328 A 56 year old man is having a long venous line inserted via the femoral vein into the right atrium for CVP measurements. The catheter is advanced through the IVC. At which of the following levels does this vessel enter the thorax?

Answer 25

Theme from 2010 ExamTheme from September 2012 ExamThe IVC passes through the diaphragm at T8.

Question 26

Question 220 of 328 A 72 year old man with carcinoma of the lung is undergoing a left pneumonectomy. The left main bronchus is divided. Which of the following thoracic vertebrae lies posterior to this structure? A. T3 B. T7 C. T6 D. T10

Answer 26

T6The left main bronchus lies at T6. Topographical anatomy of the thorax is important as it helps surgeons to predict the likely structures to be injured in trauma scenarios (so popular with examiners)

Question 27

Question 232 of 328 A builder falls off a ladder whilst laying roof tiles. He sustains a burst fracture of L3. The MRI scan shows complete cord transection at this level as a result of the injury. Which clinical sign will not be present initially?

Answer 27

Extensor plantar responseIn lower motor neuron lesions everything is reducedThe main purpose of this question is to differentiate the features of an UMN lesion and a LMN lesion. The features of a LMN lesion include: Flaccid paralysis of muscles supplied Atrophy of muscles supplied. Loss of reflexes of muscles supplied. Muscles fasciculation For lesions below L1 LMN signs will occur. Hence in an L3 lesion, there will be loss of the patella reflex but there will be no extensor plantar reflex.

Question 28

Question 243 of 328 A 40-year-old man presents with pain in his lower back and 'sciatica' for the past three days. He describes bending down to pick up a washing machine when he felt 'something go'. He now has severe pain radiating from his back down

Answer 28

L3

Question 29

Question 244 of 328 A 72 year old man is undergoing a repair of an abdominal aortic aneurysm. The aorta is cross clamped both proximally and distally. The proximal clamp is applied immediately inferior to the renal arteries. Both common iliac arterie

Answer 29

The lumbar arteries are posteriorly sited and are a common cause of back bleeding during aortic surgery. The other vessels cited all exit the aorta in the regions that have been cross clamped.

Question 30

Question 256 of 328 Which of the following is not a muscle of the rotator cuff? A. Subscapularis B. Teres minor C. Supraspinatus D. Infraspinatus E. Deltoid

Answer 30

Deltoid may abduct the shoulder and is not a rotator cuff muscle.

Question 31

Question 277 of 328 Which of the following structures is not at the level of the transpyloric plane? A. Hilum left kidney B. Superior mesenteric artery C. Fundus of the gallbladder D. Cardioesophageal junction E. Root of transver

Answer 31

Cardiooesophageal junction level = T11A knowledge of this anatomic level is commonly tested.The oesophagus extends from C6 (the lower border of the cricoid cartilage) to T11 at the cardioesophageal junction. Note that in the neonate the oesophagus extends from C4 or C5 to T9.

Question 32

Question 287 of 328 A 58 year old lady presents with a mass in the upper outer quadrant of the right breast. Which of the following statements relating to the breast is untrue? A. The internal mammary artery provides the majority of its arte

Answer 32

Nipple retraction may occur as a result of tumour infiltration of the clavipectoral fasciaNipple retraction is a feature of breast malignancy. However, it is typically caused by tumour infiltration of Coopers Ligaments that run through the breast and surround the lobules. The clavipectoral fascia encases the axillary contents. The lymphatic drainage of the breast is to the axilla and also to the internal mammary chain. The breast is well vascularised and the internal mammary artery is a branch of the subclavian artery.

Question 33

Question 292 of 328 A 72 year old man is undergoing a left pneumonectomy for carcinoma of the bronchus. As the surgeons approach the root of the lung, which structure will lie most anteriorly (in the anatomical plane)? A. Vagus nerve B. Phren

Answer 33

Phrenic nerveThe phrenic nerve is the most anteriorly located structure in the lung root. The vagus nerve lies most posteriorly.

Question 34

Question 299 of 328 The thesbian veins contribute to the venous drainage of the heart. Into which of the following structures do they primarily drain? A. Great cardiac vein B. Atrium C. Superior vena cava D. Oblique vein E. Small car

Answer 34

AtriumThe thesbian veins are numerous small veins running over the surface of the heart they drain into the heart itself. Usually this is to the atrium directly.

Question 35

Question 305 of 328 During a gangland gunfight a man is shot in the chest. The bullet passes through the posterior mediastinum (from left to right). Which of the following structures is least likely to be injured A. Thoracic duct B. Oesophagu

Answer 35

Arch of the azygos veinThe arch of the azygos vein lies in the middle mediastinum.

Question 36

Question 308 of 328 A 63 year old man is undergoing an upper GI endoscopy for dysphagia. At 33 cm a malignant looking stricture is encountered. The endoscopist attempts a balloon dilatation.Unfortunately the tumour splits through the oesophageal

Answer 36

At this position the oesophagus is still likely to be intrathoracic and located in the posterior mediastinum.

Question 37

Question 309 of 328 During a tricuspid valve repair the right atrium is opened, following establishment of cardiopulmonary bypass. Which of the following structures do not lie within the right atrium? A. Crista terminalis B. Tricuspid val

Answer 37

Trabeculae carnaeStructures within the right atrium: Musculi pectinati Crista terminalis Opening of the coronary sinus Fossa ovalisThe trabeculae carnae are located in the right ventricle.

Question 38

Question 315 of 328 A 63 year old man is undergoing a right pneumonectomy for carcinoma of the bronchus. As the surgeons approach the root of the lung, which structure will lie most posteriorly (in the anatomical plane)? A. Phrenic nerve

Answer 38

Vagus nerveThe vagus nerve is the most posteriorly located structure at the lung root. The phrenic nerve lies most anteriorly.

Question 39

Question 316 of 328 A 43 year old lady is undergoing an axillary node clearance for breast cancer. The nodal disease is bulky. During clearance of the level 3 nodes there is suddenly brisk haemorrhage. The most likely vessel responsible is:

Answer 39

Thoracoacromial arteryThe thoracoacromial artery pierces the pectoralis major and gives off branches within this space. The level 3 axillary nodes lie between pectoralis major and minor.Although the thoracodorsal trunk may be injured during an axillary dissection it does not lie within the level 3 nodes.

Question 40

Question 323 of 328 How many valves lie between the superior vena cava and the right atrium? A. None B. One C. Two D. Three E. Four

Answer 40

NoneThere are no valves which is why it is relatively easy to insert a CVP line from the internal jugular vein into the right atrium.