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Question 1
Correct
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Which of the following occurs at the transverse thoracic plane:
Your Answer: Bifurcation of the trachea
Explanation:A way to help remember the structures transected by the transverse thoracic plane is CLAPTRAP:
C: cardiac plexus
L: ligamentum arteriosum
A: aortic arch (inner concavity)
P: pulmonary trunk
T: tracheal bifurcation (carina)
R: right-to-left movement of the thoracic duct (posterior to the oesophagus)
A: azygos vein drains into superior vena cava
P: pre-vertebral fascia and pre-tracheal fascia end -
This question is part of the following fields:
- Anatomy
- Thorax
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Question 2
Correct
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When inserting a Seldinger chest drain for management of pneumothorax, the 'safe triangle' should be identified. Which of the following forms the inferior border of the 'safe triangle'?
Your Answer: 5 th intercostal space
Explanation:Care and management of the thoracostomy tubes (chest tubes) are subject to the direction and practice pattern of the responsible physician. Therefore, it is difficult to make a “one size fits all” set of instructions about the specific management recommendations for all chest tubes. It is recommended to discuss specific expectations for management with the patient’s attending physician. Facility specific Clinical Practice Guidelines (CPGs) may provide further guidance for one’s practice.
Placement of the appropriately sized chest tube is performed on the affected side. The typical landmark for placement is the 4th or 5th intercostal space (nipple line for males, inframammary fold for females) at the anterior axillary line. The space above the 5th intercostal space and below the base of the axilla that is bordered posteriorly by the trapezius and anteriorly by the pectoralis muscle has recently been described as the safe triangle. Tubes are positioned anteriorly for pneumothoraces and posteriorly for fluid processes.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 3
Correct
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Which of the following occurs primarily to produce passive expiration:
Your Answer: Relaxation of diaphragm and external intercostal muscles
Explanation:Passive expiration is produced primarily by relaxation of the inspiratory muscles (diaphragm and external intercostal muscles) and the elastic recoil of the lungs. In expiration, depression of the sternal ends of the ribs (‘pump handle’ movement), depression of the lateral shafts of the ribs (‘bucket handle’ movement) and elevation of the diaphragm result in a reduction of the thorax in an anteroposterior, transverse and vertical direction respectively. This results in a decreased intrathoracic volume and increased intrathoracic pressure and thus air is forced out of the lungs.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 4
Correct
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During quiet respiration, position of the right oblique fissure can be marked by a line drawn on the thoracic wall that:
Your Answer: Begins at the spinous process of T4, crosses the fifth intercostal space laterally and follows the contour of rib 6 anteriorly.
Explanation:During quiet respiration, the approximate position of the right oblique fissure can be marked by a line on the thoracic wall that begins at the spinous process of vertebra T4, crosses the fifth intercostal space laterally and then follows the contour of rib 6 anteriorly.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 5
Incorrect
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A 28-year-old woman with history of blunt thoracic trauma develops hypotension chest pain, and breathlessness. A bedside echocardiogram was performed and revealed a large pericardial effusion. Due to this finding, a pericardiocentesis was to be performed.
Which of the following statements is considered true regarding pericardiocentesis?Your Answer: The standard approach is the parasternal approach
Correct Answer: The needle should be aimed at the midpoint of the left clavicle
Explanation:Pericardiocentesis is a procedure done to remove fluid build-up in the sac around the heart known as the pericardium. The pericardium can be tapped from almost any reasonable location on the chest wall. However, for the usual blind pericardiocentesis, the subxiphoid approach is preferred. Ideally, 2-D echocardiography is used to guide needle insertion and the subsequent path of the needle/catheter.
In the subxiphoid approach, the needle is inserted 1 cm inferior to the left xiphocostal angle with an angle of 30 degrees from the patient’s chest with a direction towards the left mid-clavicle.
The fingers may sense a distinct give when the needle penetrates the parietal pericardium. Successful removal of fluid confirms the needle’s position.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 6
Incorrect
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The 'bucket handle' movement of the thoracic wall describes which of the following movements:
Your Answer: The clavicle moving upwards
Correct Answer: The middles of the shafts of the ribs moving upwards and laterally
Explanation:Because the middles of the shafts of the ribs are lower than either the anterior or posterior end, elevation of the ribs also moves the middles of the shafts laterally. This ‘bucket handle’ upwards and lateral movement increases the lateral dimensions of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 7
Incorrect
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The following structures all lie anteriorly to the oesophagus EXCEPT for the:
Your Answer: Left main bronchus
Correct Answer: Thoracic duct
Explanation:Posterior to the oesophagus, the thoracic duct is on the right side inferiorly but crosses to the left more superiorly (at T5).
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 8
Incorrect
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Which of the following muscles is least likely to be involved in forceful expiration:
Your Answer: Transversus thoracis
Correct Answer: External intercostal muscles
Explanation:Forceful expiration is primarily produced by the deeper thoracic muscles (internal and innermost intercostal muscles, subcostals and transversus thoracis) aided by contraction of the abdominal wall muscles which increase intra-abdominal pressure thus further reducing the volume of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 9
Incorrect
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All of the following typically occurs as part of normal inspiration except:
Your Answer: Flattening of the diaphragm
Correct Answer: Contraction of the internal intercostal muscles
Explanation:Passive inspiration is a result of contraction of the diaphragm (depressing the diaphragm) and the external intercostal muscles (elevating the ribs).
In inspiration, several movements occur. These are:
1. elevation of the sternal ends of the ribs (‘pump handle’ movement),
2. elevation of the lateral shafts of the ribs (‘bucket handle’ movement)
3. depression of the diaphragm.
These result in expansion of the thorax in an anteroposterior, transverse and vertical direction respectively. There is an increased intrathoracic volume and decreased intrathoracic pressure and air is drawn into the lungs. -
This question is part of the following fields:
- Anatomy
- Thorax
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Question 10
Incorrect
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Which coronary artery is mostly likely affected if an ECG shows ST segment elevation in leads II, III and aVF, and ST segment depression in V1-V3?
Your Answer: Left circumflex artery
Correct Answer: Right coronary artery
Explanation:A posterior wall MI occurs when posterior myocardial tissue (now termed inferobasilar), usually supplied by the posterior descending artery — a branch of the right coronary artery in 80% of individuals — acutely loses blood supply due to intracoronary thrombosis in that vessel. This frequently coincides with an inferior wall MI due to the shared blood supply.
The ECG findings of an acute posterior wall MI include the following:
1. ST segment depression (not elevation) in the septal and anterior precordial leads (V1-V4). This occurs because these ECG leads will see the MI backwards; the leads are placed anteriorly, but the myocardial injury is posterior.
2. A R/S wave ratio greater than 1 in leads V1 or V2.
3. ST elevation in the posterior leads of a posterior ECG (leads V7-V9). Suspicion for a posterior MI must remain high, especially if inferior ST segment elevation is also present.
4. ST segment elevation in the inferior leads (II, III and aVF) if an inferior MI is also present.The following ECG leads determine the location and vessels involved in myocardial infarction:
ECG Leads Location Vessel involved
V1-V2 Septal wall Left anterior descending
V3-V4 Anterior wall Left anterior descending
V5-V6 Lateral wall Left circumflex artery
II, III, aVF Inferior wall Right coronary artery (80%) or Left circumflex artery (20%)
I, aVL High lateral wall Left circumflex artery
V1, V4R Right ventricle Right coronary artery
V7-V9 Posterior wall Right coronary artery -
This question is part of the following fields:
- Anatomy
- Thorax
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Question 11
Incorrect
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A 38-year-old taxi driver sustained blunt force trauma to his anterior chest from the steering wheel of his car after falling asleep while driving headlong into an oncoming HGV lorry. Bruising around his sternum was observed, which appears to be the central point of impact.
Which of the following structures is most likely injured by the blunt force trauma?Your Answer: Left ventricle
Correct Answer: Right ventricle
Explanation:In its typical anatomical orientation, the heart has 5 surfaces formed by different internal divisions of the heart:
Anterior (or sternocostal) – Right ventricle
Posterior (or base) – Left atrium
Inferior (or diaphragmatic) – Left and right ventricles
Right pulmonary – Right atrium
Left pulmonary – Left ventricle -
This question is part of the following fields:
- Anatomy
- Thorax
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Question 12
Correct
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Which anatomical structure is divided following an emergency department anterolateral thoracotomy?
Your Answer: Latissimus dorsi
Explanation:Thoracotomy describes an incision made in the chest wall to access the contents of the thoracic cavity. Thoracotomies typically can be divided into two categories; anterolateral thoracotomies and posterolateral thoracotomies. These can be further subdivided into supra-mammary and infra-mammary and, of course, further divided into the right or left chest. Each type of incision has its utility given certain circumstances.
A scalpel is used to sharply divide the skin along the inframammary crease overlying the fifth rib. Electrocautery is then used to divide the pectoralis major muscle and serratus anterior muscle. Visualization of the proper operative field can be achieved with the division and retraction of the latissimus dorsi. Either the fourth or fifth intercostal space is then entered after the division of intercostal muscles above the rib to ensure the preservation of the neurovascular bundle. Once the patient is properly secured to the operating table, the ipsilateral arm is raised and positioned anteriorly and cephalad to rest above the head. The incision is started along the inframammary crease and extended posterolaterally below the tip of the scapula. It is then extended superiorly between the spine and the edge of the scapula, a short distance. The trapezius muscle and the subcutaneous tissues are divided with electrocautery. The serratus anterior and latissimus dorsi muscles are identified and can be retracted. The intercostal muscles are then divided along the superior border of the ribs, and the thoracic cavity is accessed.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 13
Incorrect
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Which of the following is true regarding respiration?
Your Answer: The ‘pump handle’ action of the ribs increases the transverse diameter of the chest
Correct Answer: The diaphragm is responsible for abdominal breathing
Explanation:The following are the mechanisms of breathing during inspiration and expiration, whether normal or forced.
Normal inspiration is an active process, with the diaphragm as the main muscle. The diaphragm descends, ribs move upward and outward, and the lungs become wider and taller.
In forced inspiration, which commonly occurs during exercise, the external intercostals and accessory muscles, such as the sternocleidomastoid, anterior serrati, scalenes, alae nasi, genioglossus and arytenoid are involved. The ribs move upward and outward, and the abdominal contents move downward.
Normal expiration is a passive process, while in forced expiration, the internal intercostals and abdominal muscles, such as the rectus abdominis, internal and external obliques and transversus abdominis are involved. The ribs move downward and inward, and the abdominal contents move upward.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 14
Incorrect
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Contraction of the diaphragm results in which of the following effects:
Your Answer: Increased anteroposterior dimension of the thorax
Correct Answer: Increased vertical dimension of the thorax
Explanation:Contraction of the diaphragm (as in inspiration) results in flattening (depression) of the diaphragm with an increase in vertical dimension of the thorax. This results in decreased intrathoracic pressure and increased intra-abdominal pressure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 15
Correct
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Which of the following anatomical structures is most likely the cause of oedema and erythema of the arm in a patient who underwent modified radical mastectomy and radiotherapy?
Your Answer: Axillary lymph nodes
Explanation:Arm oedema is one of the sequelae after breast cancer surgery and radiation therapy. Arm oedema in the breast cancer patient is caused by interruption of the axillary lymphatic system by surgery or radiation therapy, which results in the accumulation of fluid in subcutaneous tissue in the arm, with decreased distensibility of tissue around the joints and increased weight of the extremity. Chronic inflammatory changes result in both subcutaneous and lymph vessel fibrosis.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 16
Incorrect
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All of the following typically occurs as part of normal passive expiration except:
Your Answer: Relaxation of the external intercostal muscles
Correct Answer: Contraction of the internal intercostal muscles
Explanation:Passive expiration is produced primarily by relaxation of the inspiratory muscles (diaphragm and external intercostal muscles) in addition to the elastic recoil of the lungs.
In expiration, several movements occur. There are:
1. depression of the sternal ends of the ribs (‘pump handle’ movement),
2. depression of the lateral shafts of the ribs (‘bucket handle’ movement) and
3. elevation of the diaphragm.
These result in a reduction of the thorax in an anteroposterior, transverse and vertical direction respectively. There is then a decreased intrathoracic volume and increased intrathoracic pressure and air is forced out of the lungs. -
This question is part of the following fields:
- Anatomy
- Thorax
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Question 17
Correct
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Needle thoracentesis in a patient with a tension pneumothorax is performed at which anatomical landmark?
Your Answer: 4th or 5th intercostal space mid-axillary line
Explanation:Tension pneumothorax is a fatal disease causing acute and severe compromise of patients’ ventilation and circulation, in which case immediate decompression is necessary for better prognosis [6]. A previous study has shown that the incidence of tension pneumothorax varies from 0.2% to 1.7% in patients with prehospital trauma. Several trauma guidelines recommend needle thoracostomy as a life-saving intervention, with placement in the second intercostal space at the midclavicular line (second ICS-MCL), the fourth intercostal space at the anterior axillary line (fourth ICS-AAL), or the fifth intercostal space at the midaxillary line (fifth ICS-MAL) for tension pneumothorax in a prehospital environment.
In 2018, according to newly issued the Advanced Trauma Life Support (ATLS) guidelines, the fifth ICS-MAL was suggested as the preferred place, and an 8 cm needle rather than the common 5 cm needle was proved to increase success rate of adults’ decompression.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 18
Correct
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You are about to perform an emergency pericardiocentesis on a 26-year-old male who was involved in a car accident and is suspected of having cardiac tamponade due to signs of hypotension, muffled heart sounds, and distended neck veins. Where should you insert the needle to relieve tamponade?
Your Answer: Inferior and to the left of the xiphochondral junction
Explanation:Pericardiocentesis is a procedure that removes excess fluid from the pericardium. As a result, it’s used in cases of cardiac tamponade, which occurs when there’s too much fluid in the space around the heart.
During the procedure, a needle and a small catheter are inserted 1 to 2 cm inferior and to the left of the xiphochondral junction into the pericardial cavity.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 19
Incorrect
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The 'pump handle' movement of the thoracic wall describes which of the following movements:
Your Answer: The internal intercostal muscles elevating the ribs
Correct Answer: The anterior ends of the ribs moving upwards and forwards
Explanation:Because the anterior ends of the ribs are inferior to the posterior ends, when the ribs are elevated, the anterior end moves upwards and forwards, moving the sternum upwards and forwards in turn. This ‘pump handle’ upwards and forwards movement changes the anteroposterior (AP) dimension of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 20
Correct
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Which of the following statements is true regarding a pleural aspiration?
Your Answer: The needle should be inserted just above the upper border of the chosen rib
Explanation:Pleural aspiration describes a procedure whereby pleural fluid or air may be aspirated via a system inserted temporarily into the pleural space. This may be for diagnostic purposes (usually removing 20–50 ml fluid) or therapeutic to relieve symptoms. In the literature it is varyingly called thoracocentesis, thoracentesis or pleural aspiration.
In determining the correct patient position and site of insertion, it is important for the operator to be aware of the normal anatomy of the thorax and the pathology of the patient. Patient position is dependent on the operator preference and the site of the pathology. In the case of a posterior lying locule, this may be specific to the image-guided spot where fluid is most likely to be obtained. In most circumstances, however, the site of insertion of the needle is either in the triangle of safety or the second intercostal space in the midclavicular line. The patient may therefore either sit upright leaning forward with arms elevated but resting on a table or bed, thereby exposing the axilla, or lying on a bed in a position. The needle is inserted in the space just above the chosen rib to avoid damaging the neurovascular bundle. It is common practice to insert the needle more posteriorly for a pleural aspiration, but it should be noted that the neurovascular bundle may not be covered by the lower flange of the rib in this position and a more lateral or anterior site of insertion is considered safer.
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This question is part of the following fields:
- Anatomy
- Thorax
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SESSION STATS - PERFORMANCE PER SPECIALTY
