Thoracic II Flashcards
A 5 year old boy is playing with some small ball bearings. Unfortunately he inhales one. To which of the following lung regions is the ball most likely to settle?
A. Right lower lobe B. Left main bronchus C. Right upper lobe D. Left lower lobe E. None of the above
Right lower lobe
As the most dependent part of the right lung a small object is most likely to lodge here. Most objects will preferentially enter the right lung owing to the angle the right main bronchus takes from the trachea.
A patient presents with superior vena caval obstruction. How many collateral circulations exist as alternative pathways of venous return?
A. None B. One C. Two D. Three E. Four
4 There are 4 collateral venous systems: Azygos venous system Internal mammary venous pathway Long thoracic venous system with connections to the femoral and vertebral veins (2 pathways)
Despite this, venous hypertension still occurs.
A 53 year old man with tricuspid regurgitation is undergoing a tricuspid valve repair. The heart is opened and the musculi pectinati are identified. Where are these structures located?
A. Right ventricle B. Left ventricle C. Right atrium D. Pulmonary valve E. Aortic valve
Right atrium
The musculi pectinati are found in the atria, hence the reason that the atrial walls in the right atrium are irregular anteriorly.
The musculi pectinati of the atria are internal muscular ridges on the anterolateral surface of the chambers and they are only present in the area derived from the embryological true atrium.
A 33 year old man is stabbed in the right chest and undergoes a thoracotomy. The right lung is mobilised and the pulmonary ligament inspected. Which of the following structures does not lie within the pulmonary ligament of the right lung?
A. Pulmonary artery B. Azygos vein C. Pulmonary vein D. Bronchus E. None of the above
azygous
The pulmonary ligament is formed by a pleural condensation at the hilum of the lung. It encases the pulmonary vessels and trachea. The azygos vein is not contained within it.
A 56 year old man requires long term parenteral nutrition and the decision is made to insert a PICC line for long term venous access. This is inserted into the basilic vein at the region of the elbow. As the catheter is advanced, into which venous structure is the tip of the catheter most likely to pass from the basilic vein?
A. Subclavian vein B. Axillary vein C. Posterior circumflex humeral vein D. Cephalic vein E. Superior vena cava
axillary vein
The basilic vein drains into the axillary vein and although PICC lines may end up in a variety of fascinating locations the axillary vein is usually the commonest site following from the basilic. The posterior circumflex humeral vein is encountered prior to the axillary vein. However, a PICC line is unlikely to enter this structure because of its angle of entry into the basilic vein.
An individual is noted to have a left sided superior vena cava. By which pathway is blood from this system most likely to enter the heart?
A. Via the coronary sinus B. Via the azygos venous system and into the superior vena cava C. Via anomalies in the pumonary vascular bed D. Via the left atrium and persistent foramen ovale E. Directly into the roof of the right atrium
coronary sinus
Persistent left superior vena cava is the most common anomaly of the thoracic venous system. It is prevalent in 0.3% of the population and is a benign entity of failed involution during embryogenesis.
Which of the following structures is not located within the mediastinum?
A. Thymus B. Heart C. Great vessels D. Arch of azygos vein E. Vertebral bodies
The vertebral bodies lie outside of the mediastinum, as do the lungs.
A 22 year old man is stabbed in the chest at the level of the junction between the sternum and manubrium. Which structure is at greatest risk?
A. Left atrium B. Oesophagus C. Thyroid gland D. Inferior vena cava E. Aortic arch
aortic arch
At the level of the Angle of Louis (Manubriosternal angle), is the surface marking for the aortic arch. The oesophagus is posteriorly located and at less risk.
A 73 year old lady is admitted with brisk rectal bleeding. Despite attempts at resuscitation the bleeding proceeds to cause haemodynamic compromise. An upper GI endoscopy is normal. A mesenteric angiogram is performed and a contrast blush is seen in the region of the sigmoid colon. The radiologist decides to embolise the vessel supplying this area. At what spinal level does it leave the aorta?
A. L2 B. L1 C. L4 D. L3 E. T10
L3
The inferior mesenteric artery leaves the aorta at L3. It supplies the left colon and sigmoid. It’s proximal continuation to communicate with the middle colic artery is via the marginal artery.
A 23 year old lady with troublesome axillary hyperhidrosis is undergoing a thorascopic sympathectomy to treat the condition. Which of the following structures will need to be divided to access the sympathetic trunk?
A. Intercostal vein B. Intercostal artery C. Parietal pleura D. Visceral pleura E. None of the above
Parietal pleura
The sympathetic chain lies posterior to the parietal pleura. During a thorascopic sympathetomy this structure will need to be divided. The intercostal vessels lie posteriorly. They may be damaged with troublesome bleeding but otherwise are best left alone as deliberate division will not improve surgical access.
Secretion of saliva by the parotid gland is controlled by postsynaptic parasympathetic fibres originating in the inferior salivatory nucleus; these leave the brain via the tympanic nerve (branch of glossopharyngeal nerve (CN IX), travel through the tympanic plexus (located in the middle ear), and then form the lesser petrosal nerve until reaching the otic ganglion. After synapsing in the Otic ganglion, the postganglionic (postsynaptic) fibres travel as part of the auriculotemporal nerve (a branch of the mandibular nerve (V3) to reach the parotid gland.Ser
serosa
The oesophageal wall lacks the serosa layer
The wall lacks a serosa which can make the wall hold sutures less securely.
Where is the ‘safe triangle’ for chest drain insertion located?
A. 4th intercostal space, mid axillary line B. 5th intercostal space, mid axillary line C. 4th intercostal space, mid scapular line D. 5th intercostal space, mid scapular line E. 4th intercostal space, mid clavicular line
‘Safe Triangle’ for chest drain insertion:
5th intercostal space, mid axillary line
Your consultant decides to perform an open inguinal hernia repair under local anaesthesia. Which of the following dermatomal levels will require blockade?
A. T10 B. T12 C. T11 D. S1 E. S2
T12
At which level does the aorta perforate the diaphragm?
A. T10 B. T9 C. T8 D. T11 E. T12
T12
Diaphragm aperture levels
Vena cava T8
Oesophagus T10
Aortic hiatus T12
Memory aid:
T8 (8 letters) = vena cava
T10 (10 letters) = oesophagus
T12 (12 letters) = aortic hiatus
At which level is the hilum of the left kidney located?
A. L1 B. L2 C. T12 D. T11 E. L3
L1
Remember L1 ('left one') is the level of the hilum of the left kidney
Theme from April 2012 exam
This is commonly tested in the mrcs exam.
You are assisting in an open right adrenalectomy for a large adrenal adenoma. The consultant is distracted and you helpfully pull the adrenal into the wound to improve the view. Unfortunately this is followed by brisk bleeding. The vessel responsible for this is most likely to be:
A. Portal vein B. Phrenic vein C. Right renal vein D. Superior mesenteric vein E. Inferior vena cava
IVC
It drains directly via a very short vessel. If the sutures are not carefully tied then it may be avulsed off the IVC. An injury best managed using a Satinsky clamp and a 6/0 prolene suture.
A 63 year old man is undergoing a coronary artery bypass procedure. During the median sternotomy which structure would routinely require division?
A. Parietal pleura B. Interclavicular ligament C. Internal mammary artery D. Brachiocephalic vein E. Left vagus nerve
Interclavicular ligament
The interclavicular ligament lies at the upper end of a median sternotomy and is routinely divided to provide access. The pleural reflections are often encountered and should not be intentionally divided, if they are, then a chest drain will need to be inserted on the affected side as collections may then accumulate in the pleural cavity. Other structures encountered include the pectoralis major muscles, again if the incision is truly midline then these should not require formal division. The close relationship of the brachiocephalic vein should be borne in mind and it should be avoided, iatrogenic injury to this structure will result in considerable haemorrhage.
A 34 year old male is being examined in the pre-operative assessment clinic. A murmur is identified in the 5th intercostal space just next to the left side of the sternum. From where is it most likely to have originated?
A. Mitral valve B. Aortic valve C. Pulmonary valve D. Right ventricular aneurysm E. Tricuspid valve
The tricuspid valve is generally referred to being best auscultated adjacent to the sternum. The plane of projected sound from the mitral area is best heard in the region of the cadiac apex.
Sites of auscultation
Valve Site
Pulmonary valve Left second intercostal space, at the upper sternal border
Aortic valve Right second intercostal space, at the upper sternal border
Mitral valve Left fifth intercostal space, just medial to mid clavicular line
Tricuspid valve Left fifth intercostal space, at the lower left sternal border
During an Ivor Lewis Oesophagectomy for carcinoma of the lower third of the oesophagus which structure is divided to allow mobilisation of the oesophagus?
A. Vagus nerve B. Azygos vein C. Right inferior lobar bronchus D. Phrenic nerve E. Pericardiophrenic artery
The azygos vein is routinely divided during an oesophagectomy to allow mobilisation. It arches anteriorly to insert into the SVC on the right hand side.
Which of the following statements relating to quadratus lumborum is false?
A. Causes flexion of the thoracic spine B. Causes the rib cage to be pulled down C. Innervated by anterior primary rami of T12 and L1-3 D. Attached to the iliac crest E. Inserts into the 12th rib
Causes flexion of the thoracic spine
The rectus abdominis causes flexion of the thoracic spine.
Attached to the medial iliac crest and iliolumbar ligament.
Inserts: 12th rib
Action: pulls the rib cage inferiorly. Lateral flexion.
Nerve supply: anterior primary rami of T12 and L1-3
A 67 year old man is undergoing an angiogram for gastro intestinal bleeding. The radiologist advances the catheter into the coeliac axis. At what spinal level does this vessel typically arise from the aorta?
A. T10 B. L3 C. L4 D. T12 E. None of the above
T12
The coeliac axis lies at T12, it takes an almost horizontal angle off the aorta. It has three major branches.
Abdominal aortic branches
Branches Level Paired Type
Inferior phrenic T12 (Upper border)Yes. Parietal
Coeliac T12 No Visceral
Superior mesenteric L1 No Visceral
Middle suprarenal L1 Yes. Visceral
Renal L1-L2. Yes. Visceral
Gonadal L2 Yes. Visceral
Lumbar L1-L4. Yes. Parietal
Inferior mesenteric L3 No. Visceral
Median sacral L4 No. Parietal
Common iliac L4 Yes. Terminal
At which of the following levels does the inferior vena cava exit the abdominal cavity?
A. T6 B. T7 C. T10 D. T8 E. T12
T8
Transpyloric plane
Level of the body of L1
Pylorus stomach Left kidney hilum (L1- left one!) Right hilum of the kidney (1.5cm lower than the left) Fundus of the gallbladder Neck of pancreas Duodenojejunal flexure Superior mesenteric artery Portal vein Left and right colic flexure Root of the transverse mesocolon 2nd part of the duodenum Upper part of conus medullaris Spleen
Can be identified by asking the supine patient to sit up without using their arms. The plane is located where the lateral border of the rectus muscle crosses the costal margin.
Anatomical planes
Subcostal plane Lowest margin of 10th costal cartilage
Intercristal plane Level of body L4 (highest point of iliac crest)
Intertubercular plane Level of body L5
Common level landmarks Inferior mesenteric artery L3 Bifurcation of aorta into common iliac arteries L4 Formation of IVC L5 (union of common iliac veins) Diaphragm apertures Vena cava T8 Oesophagus T10 Aortic hiatus T12
Which of the positions listed below best describes the location of the coeliac plexus?
A. Anterolateral to the aorta B. Posterolateral to the aorta C. Anterolateral to the sympathetic chain D. Anteromedial to the sympathetic chain E. Posterior to L1
Anterolateral to the aorta
The coeliac plexus us the largest of the autonomic plexuses. It is located on a level of the last thoracic and first lumbar vertebrae. It surrounds the coeliac axis and the SMA. It lies posterior to the stomach and the lesser sac. It lies anterior to the crura of the diaphragm and the aorta. The plexus and ganglia are joined are joined by the greater and lesser splanchnic nerves on both sides and branches from both the vagus and phrenic nerves.
A patient has a chest drain insertion. There is fresh blood at the chest drain insertion area. Which vessel has been damaged?
A. Pericardiophrenic artery B. Intercostal vein C. Right ventricle D. Vagus artery E. Intercostal artery
Intercostal artery
Within the intercostal spaces there are thin, strong muscles, intercostal vessels, nerves and lymphatics. There are 3 intercostal muscle layers corresponding to the lateral abdominal wall; external, internal, innermost intercostals. At the mid axillary line there are thin intracostals which is an extension of the internal intercostal muscle. In each intercostal space lies the neurovascular bundle, comprising, from superior to inferiorly; the posterior intercostal vein, artery and nerve, lying protected in the subcostal groove of the rib above and situated between the second and third layer of the intercostal muscles. These blood vessels anastomose anteriorly with the anterior intercostal vessels, which arise from the internal thoracic artery and vein.
