Thorax Flashcards

1
Q
  1. A 32-year-old patient who weighs 275 lb comes to the doctor’s office. On the surface of the chest, the physician is able to locate the apex of the heart:
    (A) At the level of the sternal angle
    (B) In the left fourth intercostal space
    (C) In the left fifth intercostal space
    (D) In the right fifth intercostal space
    (E) At the level of the xiphoid process of the sternum
A

C. On the surface of the chest, the apex of the heart can be located in the left fifth intercostal space slightly medial to the midclavicular (or nipple) line. The sternal angle is located at the level where the second ribs articulate with the sternum. The xiphoid process lies at the level of T10 vertebra.

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2
Q
  1. A 43-year-old female patient has been lying down on the hospital bed for more than 4 months. Her normal, quiet expiration is achieved by contraction of which of the follow- ing structures?
    (A) Elastic tissue in the lungs and thoracic wall
    (B) Serratus posterior superior muscles
    (C) Pectoralis minor muscles
    (D) Serratus anterior muscles
    (E) Diaphragm
A

A. Normal, quiet expiration is achieved by contraction of extensible tissue in the lungs and the thoracic wall. The serratus posterior superior muscles, diaphragm, pectoralis major, and serratus anterior are muscles of inspiration.

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3
Q
  1. A 23-year-old man received a gunshot wound, and his greater splanchnic nerve was destroyed. Which of the following nerve fibers would be injured?
    (A) General somatic afferent (GSA) and pre- ganglionic sympathetic fibers
    (B) General visceral afferent (GVA) and post- ganglionic sympathetic fibers
    (C) GVA and preganglionic sympathetic fibers
    (D) General somatic efferent (GSE) and post-ganglionic sympathetic fibers
    (E) GVA and GSE fibers
A

C. The greater splanchnic nerves contain general visceral afferent (GVA) and pre- ganglionic sympathetic general visceral efferent (GVE) fibers.

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4
Q
  1. A 17-year-old boy was involved in a gang fight, and a stab wound severed the white rami communicantes at the level of his sixth thoracic vertebra. This injury would result in degeneration of nerve cell bodies in which of the following structures?
    (A) Dorsal root ganglion and anterior horn of the spinal cord
    (B) Sympathetic chain ganglion and dorsal root ganglion
    (C) Sympathetic chain ganglion and posterior horn of the spinal cord
    (D) Dorsal root ganglion and lateral horn of the spinal cord
    (E) Anterior and lateral horns of the spinal cord
A

D. The white rami communicantes contain preganglionic sympathetic GVE fibers and GVA fibers, whose cell bodies are located in the lateral horn of the spinal cord and the dor- sal root ganglia. The sympathetic chain ganglion contains cell bodies of the postganglionic sym- pathetic nerve fibers. The anterior horn of the spinal cord contains cell bodies of the GSE fibers. The dorsal root ganglion contains cell bodies of GSA and GVA fibers.

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5
Q
  1. A 27-year-old cardiac patient with an irregular heartbeat visits her doctor’s office for examination. Where should the physician place the stethoscope to listen to the sound of the mitral valve?
    (A) Over the medial end of the second left intercostal space
    (B) Over the medial end of the second right intercostal space
    (C) In the left fourth intercostal space at the midclavicular line
    (D) In the left fifth intercostal space at the mid-clavicular line
    (E) Over the right half of the lower end of the body of the sternum
A

D. The mitral valve (left atrioventricular [AV] valve) produces the apical beat (thrust) of the heart, which is most audible over the left fifth intercostal space at the midclavicular line. The pulmonary valve is most audible over the medial end of the second left intercostal space, the aortic valve is most audible over the medial end of the second right intercostal space, and the right AV valve is most audible over the right half of the lower end of the body of the sternum.

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6
Q
6. A19-year-old man came to the emergency department, and his angiogram exhibited that he was bleeding from the vein that is accompanied by the posterior interventricular artery. Which of the following veins is most likely to be ruptured?
(A) Great cardiac vein
(B) Middle cardiac vein
(C) Anterior cardiac vein
(D) Small cardiac vein
(E) Oblique veins of the left atrium
A

B. The middle cardiac vein ascends in the posterior interventricular groove, accompanied by the posterior interventricular branch of the right coronary artery. The great cardiac vein is accompanied by the anterior interventricular artery, the anterior cardiac vein drains directly into the right atrium, and the small cardiac vein is accompanied by the marginal artery.

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7
Q
7. A 37-year-old patient with palpitation was examined by her physician, and one of the diagnostic records included a posterior–anterior chest radiograph. Which of the following comprises the largest portion of the sternocostal surface of the heart seen on the radiograph?
(A) Left atrium
(B) Right atrium
(C) Left ventricle
(D) Right ventricle
(E) Base of the heart
A

D. The right ventricle forms a large part of the sternocostal surface of the heart. The left atrium occupies almost the entire posterior surface of the right atrium. The right atrium occupies the right aspect of the heart. The left ventricle lies at the back of the heart and bulges roundly to the left. The base of the heart is formed by the atria, which lie mainly behind the ventricles.

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8
Q
8. A 5-year-old girl is brought to the emergency department because of difficulty breath- ing (dyspnea), palpitations, and shortness of breath. Doppler study of the heart reveals an atrial septal defect (ASD). This malformation usually results from incomplete closure of which of the following embryonic structures?
(A) Ductus arteriosus
(B) Ductus venosus
(C) Sinus venarum
(D) Foramen ovale
(E) Truncus arteriosus
A

D. An atrial septal defect (ASD) is a congenital defect in the interatrial septum. During partitioning of the two atria, the opening in the foramen secundum (the foramen ovale) usually closes at birth. If this foramen ovale is not closed completely, this would result in an ASD, shunting blood from the left atrium to the right atrium.

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9
Q
9. A 54-year-old patient is implanted with an artificial cardiac pacemaker. Which of the following conductive tissues of the heart had a defective function that required the pacemaker?
(A) Atrioventricular (AV) bundle
(B) AV node
(C) Sinoatrial (SA) node
(D) Purkinje fiber
(E) Moderator band
A

C. The sinoatrial (SA) node initiates the impulse of contraction and is known as the pacemaker of the heart. Impulses from the SA node travel through the atrial myocardium to the AV node and then race through the AV bundle (bundle of His), which divides into the right and left bundle branches. The bundle breaks up into terminal conducting fibers (Purkinje fibers) to spread out into the ventricular walls. The moderate band carries the right limb of the AV bundle from the septum to the sternocostal wall of the ventricle.

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10
Q
10. A thoracic surgeon removed the right middle lobar (secondary) bronchus along with lung tissue from a 57-year-old heavy smoker with lung cancer. Which of the following broncho- pulmonary segments must contain cancerous tissues?
(A) Medial and lateral
(B) Anterior and posterior
(C) Anterior basal and medial basal
(D) Anterior basal and posterior basal
(E) Lateral basal and posterior basal
A

A. The right middle lobar (secondary) bronchus leads to the medial and lateral bronchopulmonary segments. The right superior lobar bronchus divides into the superior, posterior, and anterior segmental (tertiary) bronchi. The right inferior lobar bronchus has the anterior, lateral, posterior, and anterior segmental bronchi.

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11
Q
11. The bronchogram of a 45-year-old female smoker shows the presence of a tumor in the eparterial bronchus. Which airway is most likely blocked?
(A) Left superior bronchus
(B) Left inferior bronchus
(C) Right superior bronchus
(D) Right middle bronchus 
(E) Right inferior bronchus
A

C. The eparterial bronchus is the right superior lobar (secondary) bronchus; all
of the other bronchi are hyparterial bronchi.

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12
Q
  1. An 83-year-old man with a typical coro- nary circulation has been suffering from an embolism of the circumflex branch of the left coronary artery. This condition would result in ischemia of which of the following areas of the heart?
    (A) Anterior part of the left ventricle
    (B) Anterior interventricular region (C) Posterior interventricular region (D) Posterior part of the left ventricle
    (E) Anterior part of the right ventricle
A

D. The circumflex branch of the left coronary artery supplies the posterior portion of the left ventricle. The anterior interventricular artery supplies the anterior aspects of the right and left ventricles and the anterior interventricular septum.

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13
Q
  1. A 44-year-old man with a stab wound was brought to the emergency department, and a physician found that the patient was suffering from a laceration of his right phrenic nerve. Which of the following conditions has likely occurred?
    (A) Injury to only GSE fibers
    (B) Difficulty in expiration
    (C) Loss of sensation in the fibrous pericardium and mediastinal pleura
    (D) Normal function of the diaphragm
    (E) Loss of sensation in the costal part of the diaphragm
A

C. The phrenic nerve supplies the pericardium and mediastinal and diaphragmatic (central part) pleura and the diaphragm, an important muscle of inspiration. It contains general somatic efferent (GSE), general somatic afferent (GSA), and GVE (postganglionic sympathetic) fibers. The costal part of the diaphragm receives GSA fibers from the intercostal nerves.

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14
Q
  1. An 8-year-old boy with ASD presents to
    a pediatrician. This congenital heart defect shunts blood from the left atrium to the right atrium and causes hypertrophy of the right atrium, right ventricle, and pulmonary trunk. Which of the following veins opens into the hypertrophied atrium?
    (A) Middle cardiac vein
    (B) Small cardiac vein
    (C) Oblique cardiac vein
    (D) Anterior cardiac vein
    (E) Right pulmonary vein
A

D. The anterior cardiac vein drains into the right atrium. The middle, small, and oblique cardiac veins drain into the coronary sinus. The right and left pulmonary veins drain into the left atrium.

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15
Q
15. A 37-year-old patient with severe chest pain, shortness of breath, and congestive heart failure was admitted to a local hospital. His coronary angiograms reveal a thrombosis in the circumflex branch of the left coronary artery. Which of the following conditions could result from the blockage of blood flow in the circum- flex branch?
(A) Tricuspid valve insufficiency
(B) Mitral valve insufficiency
(C) Ischemia of AV node
(D) Paralysis of pectinate muscle
(E) Necrosis of septomarginal trabecula
A

B. The circumflex branch of the left coronary artery supplies the left ventricle, and thus its blockage of blood flow results in necrosis of myocardium in the left ventricle, producing mitral valve insufficiency. The tricuspid valve, AV node, pectinate muscles, and septomarginal trabecula are present in the right atrium and ventricle.

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16
Q
16. A 75-year-old patient has been suffering from lung cancer located near the cardiac notch, a deep indentation on the lung. Which of the following lobes is most likely to be excised?
(A) Superior lobe of the right lung
(B) Middle lobe of the right lung
(C) Inferior lobe of the right lung
(D) Superior lobe of the left lung
(E) Inferior lobe of the left lung
A

D. The cardiac notch is a deep indentation of the anterior border of the superior lobe of the left lung. Therefore, the right lung is not involved.

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17
Q
17. A thoracentesis is performed to aspirate an abnormal accumulation of fluid in a 37-year- old patient with pleural effusion. A needle should be inserted at the midaxillary line between which of the following two ribs so as to avoid puncturing the lung?
(A) Ribs 1 and 3
(B) Ribs 3 and 5
(C) Ribs 5 and 7
(D) Ribs 7 and 9
(E) Ribs 9 and 11
A

D. A thoracentesis is performed for aspiration of fluid in the pleural cavity at
or posterior to the midaxillary line, one or two intercostal spaces below the fluid level but not below the ninth intercostal space and, therefore, between ribs 7 and 9. Other intercostals spaces are not preferred.

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18
Q
18. A newborn baby is readmitted to the hospital with hypoxia and upon testing is found to have pulmonary stenosis, dextraposition of the aorta, interventricular septal defect, and hyper- trophy of the right ventricle. Which of the following is best described by these symptoms?
(A) ASD
(B) Patent ductus arteriosus
(C) Tetralogy of Fallot
(D) Aortic stenosis
(E) Coarctation of the aorta
A

C. Tetralogy of Fallot is a combination of congenital cardiac defects consisting
of (a) pulmonary stenosis, (b) dextraposition of the aorta (so that it overrides the ventricular septum and receives blood from the right ventricle), (c) ventricular septal defect (VSD), and
(d) right ventricular hypertrophy. ASD is a congenital defect in the atrial septum, resulting from a patent foramen ovale. Patent ductus arteriosus shunts blood from the pulmonary trunk to
the aorta, bypassing the lungs. Aortic stenosis is an abnormal narrowing of the aortic valve ori- fice, impeding the blood flow. Coarctation of the aorta is a congenital constriction of the aorta, commonly occurs just distal to the left subclavian artery, causing upper limb hypertension and diminished blood flow to the lower limbs and abdominal viscera.

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19
Q
19. A 33-year-old patient is suffering from a sudden occlusion at the origin of the descend- ing (thoracic) aorta. This condition would most likely decrease blood flow in which of the following intercostal arteries?
(A) Upper six anterior
(B) All of the posterior
(C) Upper two posterior
(D) Lower anterior
(E) Lower six posterior
A

E. The first two posterior intercostal arteries are branches of the highest (supe- rior) intercostal artery of the costocervical trunk; the remaining nine branches are from the thoracic aorta. The internal thoracic artery gives off the upper six anterior intercostal arteries and is divided into the superior epigastric and musculophrenic arteries, which gives off anterior intercostal arteries in the 7th, 8th, and 9th intercostal spaces and ends in the 10th intercostal space where it anastomoses with the deep circumflex iliac artery.

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20
Q
  1. A 56-year-old patient recently suffered a myocardial infarction in the area of the apex of the heart. The occlusion by atherosclerosis is in which of the following arteries?
    (A) Marginal artery
    (B) Right coronary artery at its origin
    (C) Anterior interventricular artery
    (D) Posterior interventricular artery
    (E) Circumflex branch of the left coronary
    artery
A

C. The apex of the heart typically receives blood from the anterior interventricu- lar branch of the left coronary artery. The marginal artery supplies the right inferior margin of the right ventricle, the right coronary artery at its origin supplies the right atrium and ventricle, and the posterior interventricular artery and a circumflex branch of the left coronary artery supply the left ventricle.

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21
Q
21. A 75-year-old woman was admitted to a local hospital, and bronchograms and radiographs revealed a lung carcinoma in her left lung. Which of the following structures or characteristics does the cancerous lung contain?
(A) Horizontal fissure
(B) Groove for superior vena cava (SVC) 
(C) Middle lobe
(D) Lingula
(E) Larger capacity than the right
A

D. The lingula is the tongue-shaped portion of the upper lobe of the left lung. The right lung has a groove for the horizontal fissure, superior vena cava (SVC), and middle lobe and has a larger capacity than the left lung.

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22
Q
  1. An 18-year-old girl is thrust into the steering wheel while driving and experiences difficulty in expiration. Which of the following muscles is most likely damaged?
    (A) Levator costarum
    (B) Innermost intercostal muscle (C) External intercostal muscle (D) Diaphragm
    (E) Muscles of the abdominal wall
A

E. The abdominal muscles are the major muscles of expiration, whereas the other distractors are muscles of inspiration.

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23
Q
23. A 78-year-old patient presents with an advanced cancer in the posterior mediastinum. The surgeons are in a dilemma as to how to manage the condition. Which of the following structures is most likely damaged?
(A) Brachiocephalic veins 
(B) Trachea
(C) Arch of the azygos vein 
(D) Arch of the aorta
(E) Hemiazygos vein
A

E. The hemiazygos vein is located in the posterior mediastinum. The brachiocephalic veins, trachea, and arch of the aorta are located in the superior mediastinum, whereas the arch of the azygos vein is found in the middle mediastinum.

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24
Q
  1. A 46-year-old patient comes to his doctor’s office and complains of chest pain and head- ache. His computed tomography (CT) scan reveals a tumor located just superior to the root of the right lung. Blood flow in which of the following veins is most likely blocked by this tumor?
    (A) Hemiazygos vein
    (B) Arch of the azygos vein
    (C) Right subclavian vein
    (D) Right brachiocephalic vein (E) Accessory hemiazygos vein
A

B. The azygos vein arches over the root of the right lung and empties into the
SVC. Other veins do not pass over the root of the right lung.

25
Q
  1. A 21-year-old patient with a stab wound reveals a laceration of the right vagus nerve proximal to the origin of the recurrent laryngeal nerve. Which of the following conditions would most likely result from this lesion?
    (A) Contraction of bronchial muscle
    (B) Stimulation of bronchial gland secretion
    (C) Dilation of the bronchial lumen
    (D) Decrease in cardiac rate
    (E) Constriction of coronary artery
A

C. The parasympathetic nerve fibers in the vagus nerve constrict the bronchial lumen, contract bronchial smooth muscle, stimulate bronchial gland secretion, decrease heart rate, and constrict the coronary artery. The vagus nerve also carries afferent fibers of pain, cough reflex, and stretch of the lung (during inspiration).

26
Q
  1. A neonate appears severely cyanotic and breathing rapidly. Cardiac echocardiogram reveals that the aorta lies to the right of the pul- monary trunk. Which of the following is most likely occurred during development?
    (A) AP septum failed to develop in a spiral fashion
    (B) Excessive resorption of septum primum
    (C) Pulmonary valve atresia
    (D) Persistent truncus arteriosus
    (E) Coarctation of the aorta
A

A. Failure of the aorticopulmonary septum results in transposition of the great vessels, exhibiting that the aorta is to the right of the pulmonary trunk. Cyanosis is common in transposition of the great vessels. Excessive resorption of septum primum results in a secundum type of ASD. Pulmonary valve atresia may result in cyanosis, but it will not cause the aorta to be to the right of the pulmonary trunk. A persistent truncus arteriosus is caused by lack of development of the aorticopulmonary septum resulting in a single outflow track. Coarctation of the aorta is a severe narrowing of the aorta.

27
Q
  1. A 12-year-old boy was admitted to a local hospital with a known history of heart problems. His left ventricular hypertrophy could result from which of the following conditions?
    (A) A constricted pulmonary trunk
    (B) An abnormally small left AV opening
    (C) Improper closing of the pulmonary valves
    (D) An abnormally large right AV opening
    (E) Stenosis of the aorta
A

E. Stenosis of the aorta can cause left ventricular hypertrophy. Right ventricular hypertrophy may occur as a result of pulmonary stenosis, pulmonary and tricuspid valve defects, or mitral valve stenosis.

28
Q
  1. A 31-year-old man was involved in a severe automobile accident and suffered laceration of the left primary bronchus. The damaged primary bronchus:
    (A) Has a larger diameter than the right primary bronchus
    (B) Often receives more foreign bodies than the right primary bronchus
    (C) Gives rise to the eparterial bronchus
    (D) Is longer than the right primary bronchus
    (E) Runs under the arch of the azygos vein
A

D. The right primary bronchus is shorter than the left one and has a larger diam- eter. More foreign bodies enter it via the trachea because it is more vertical than the left primary bronchus. The right primary bronchus runs under the arch of the azygos vein and gives rise to the eparterial bronchus.

29
Q
  1. A 62-year-old woman who is a heavy smoker has an advanced lung cancer that spread into her right third posterior intercostal space pos- terior to the midaxillary line. If cancer cells
    are carried in the venous drainage, they would travel first to which of the following veins?
    (A) SVC
    (B) Right superior intercostal vein
    (C) Right brachiocephalic vein
    (D) Azygos vein
    (E) Hemiazygos vein
A

B. The superior intercostal vein is formed by the union of the second, third, and fourth posterior intercostal veins and drains into the azygos vein on the right and the brachiocephalic vein on the left. The azygos vein drains into the SVC. The hemiazygos vein usually drains into the azygos vein.

30
Q
30. A radiologist examines posterior–anterior chest radiographs of a 27-year-old victim of a car accident. Which of the following structures forms the right border of the cardiovascular silhouette?
(A) Arch of the aorta
(B) Pulmonary trunk
(C) SVC
(D) Ascending aorta (E) Left ventricle
A

C. A cardiovascular silhouette or cardiac shadow is the contour of the heart and great vessels seen on posterior–anterior chest radiographs. Its right border is formed by the SVC, right atrium, and inferior vena cava; its left border is formed by the aortic arch (aortic knob), pulmonary trunk, left auricle, and left ventricle. The ascending aorta becomes the arch of the aorta and is found in the middle of the heart.

31
Q
31. A 37-year-old man is brought to the emergency department complaining of severe chest pain. His angiogram reveals thromboses of both brachiocephalic veins just before entering the superior vena cava. This condition would most likely cause a dilation of which of the following veins?
(A) Azygos
(B) Hemiazygos
(C) Right superior intercostal 
(D) Left superior intercostal 
(E) Internal thoracic
A

D. The left superior intercostal vein is formed by the second, third, and fourth posterior intercostal veins and drains into the left brachiocephalic vein. The right superior inter- costal vein drains into the azygos vein, which in turn drains into the SVC. The hemiazygos vein drains into the azygos vein, whereas the internal thoracic vein empties into the brachiocephalic vein.

32
Q
  1. A cardiologist is on clinical rounds with her medical students. She asks them, “During the cardiac cycle, which of the following events occurs?”
    (A) AV valves close during diastole
    (B) Aortic valve closes during systole
    (C) Pulmonary valve opens during diastole
    (D) Blood flow in coronary arteries is maximal
    during diastole
    (E) Aortic valve closes at the same time as AV
    valve
A

D. During diastole, the AV valves open, and the aortic and pulmonary valves close; whereas during systole, the AV valves close, and the aortic and pulmonary valves open.

33
Q
33. Coronary angiographs of a 44-year-old male patient reveal an occlusion of the circumflex branch of the left coronary artery. This patient has been suffering from myocardial infarction in which of the following areas?
(A) Right and left ventricles 
(B) Right and left atria
(C) Interventricular septum 
(D) Apex of the heart
(E) Left atrium and ventricle
A

E. The left atrium and ventricle receive blood from the circumflex branch of the left coronary artery. The interventricular septum and the apex of the heart are supplied by the anterior interventricular branch of the left coronary artery. The right ventricle receives blood from the anterior interventricular artery and the marginal branch of the right coronary artery. The right atrium receives blood from the right coronary artery.

34
Q
  1. A patient has a small but solid tumor in the mediastinum, which is confined at the level of the sternal angle. Which of the following structures would most likely be found at this level?
    (A) Bifurcation of the trachea
    (B) Beginning of the ascending aorta (C) Middle of the aortic arch
    (D) Articulation of the third rib with the
    sternum
    (E) Superior border of the superior
    mediastinum
A

A. The sternal angle is the junction of the manubrium and the body of the sternum. It is located at the level where the second rib articulates with the sternum, the trachea bifurcates into the right and left bronchi, and the aortic arch begins and ends. It marks the end of the ascending aorta and the beginning of the descending aorta, and it forms the inferior border of the superior mediastinum.

35
Q
  1. A 37-year-old house painter fell from a ladder and fractured his left third rib and the structures with which it articulated. Which of the following structures would most likely be damaged?
    (A) Manubrium of the sternum
    (B) Body of the second thoracic vertebra
    (C) Spinous process of the third thoracic
    vertebra
    (D) Body of the fourth thoracic vertebra
    (E) Transverse process of the second thoracic
    vertebra
A

B. The third rib articulates with the body of the sternum, bodies of the second and third thoracic vertebrae, and transverse process of the third thoracic vertebra.

36
Q
36. A 45-year-old woman presents with a tumor confined to the posterior mediastinum. This could result in compression of which of the following structures?
(A) Trachea
(B) Descending aorta
(C) Arch of the aorta
(D) Arch of the azygos vein
(E) Phrenic nerve
A

B. The descending aorta is found in the posterior mediastinum. The superior mediastinum contains the trachea and arch of the aorta, and the middle mediastinum contains the ascending aorta, arch of the azygos vein, and main bronchi. The phrenic nerve runs in the middle mediastinum.

37
Q
  1. A 62-year-old patient with pericardial effusion comes to a local hospital for aspiration
    of pericardial fluid by pericardiocentesis. The needle is inserted into the pericardial cavity through which of the following intercostal spaces adjacent to the sternum?
    (A) Right fourth intercostal space
    (B) Left fourth intercostal space
    (C) Right fifth intercostal space
    (D) Left fifth intercostal space
    (E) Right sixth intercostal space
A

D. To aspirate pericardial fluid, the needle should be inserted into the pericardial cavity through the fifth intercostals space just left to the sternum. Because of the cardiac notch, the needle misses the pleura and lungs, but it penetrates the pericardium. Lung tissues lie beneath the fourth and sixth intercostal spaces.

38
Q
  1. The attending faculty in the coronary intensive care unit demonstrates to his students
    a normal heart examination. The first heart sound is produced by near-simultaneous closure of which of the following valves?
    (A) Aortic and tricuspid
    (B) Aortic and pulmonary
    (C) Tricuspid and mitral
    (D) Mitral and pulmonary
    (E) Tricuspid and pulmonary
A

C. The first heart sound (“lub”) is produced by the closure of the tricuspid and mitral valves, whereas the second heart sound (“dub”) is produced by the closure of the aortic and pulmonary valves.

39
Q
39. A 27-year-old patient with Marfan syndrome has an aneurysm of the aortic arch. This may compress which of the following structures?
(A) Right vagus nerve
(B) Left phrenic nerve
(C) Right sympathetic trunk
(D) Left recurrent laryngeal nerve
(E) Left greater splanchnic nerve
A

D. The left recurrent laryngeal nerve loops around the arch of the aorta near the ligamentum arteriosum, whereas the right recurrent laryngeal nerve hooks around the right subclavian artery. All other nerves are not closely associated with the aortic arch.

40
Q
  1. A 47-year-old man with a known atrial fibrillation returns to see his cardiologist for follow-up of his cardiac health. The right atrium is important in this case because it:
    (A) Receives blood from the oblique cardiac vein
    (B) Is associated with the apex of the heart
    (C) Contains the SA node
    (D) Receives the right pulmonary vein
    (E) Is hypertrophied by pulmonary stenosis
A

C. The SA and AV nodes are in the wall of the right atrium and are not associated with the apex of the heart. The oblique cardiac vein drains into the coronary sinus, and the pulmonary veins empty into the left atrium. The right ventricle is hypertrophied by the pulmonary stenosis.

41
Q
41. A 57-year-old patient has a heart murmur resulting from the inability to maintain constant tension on the cusps of the AV valve. Which of the following structures is most likely damaged?
(A) Crista terminalis
(B) Septomarginal trabecula 
(C) Chordae tendineae
(D) Pectinate muscle
(E) Anulus fibrosus
A

C. The chordae tendineae are tendinous strands that extend from the papillary muscles to the cusps of the valve. The papillary muscles and chordae tendineae prevent the cusps from being everted into the atrium during ventricular contraction.

42
Q
  1. A mother with diabetes gives birth to a baby who is diagnosed as having dextroposition of the aorta and the pulmonary trunk with cyanosis and shortness of breath. Which of the following structures is required to remain patent until surgical correction of the deformity?
    (A) Umbilical arteries (B) Umbilical vein
    (C) Ductus arteriosus (D) Ductus venosus (E) Sinus venosus
A

C. A patent ductus arteriosus shunts blood from the pulmonary trunk to the aorta, partially bypassing the lungs, and thus allowing mixed blood to reach the body tissues and causing cyanosis. Dextroposition or transposition of the great arteries must be accompa- nied by a VSD or a patent ductus arteriosus for the infant to survive. The transposition causes oxygenated blood to pass from the left ventricle into the pulmonary trunk and then into the lungs, but deoxygenated blood travels from the right ventricle into the aorta and then into the systemic circulation.

43
Q
43. During early development of the respiratory system, the laryngotracheal tube maintains communication with the primitive foregut. Which of the following embryonic structures is most likely responsible for partitioning these two embryonic structures?
(A) Tracheoesophageal folds
(B) Tracheoesophageal fistula
(C) Tracheoesophageal septum 
(D) Laryngotracheal diverticulum 
(E) Laryngotracheal septum
A

C. The tracheoesophageal septum is formed by the fusion of the tracheoesopha- geal folds in the midline. This septum divides the foregut into a ventral portion, the laryngo- tracheal tube (primordium of the larynx, trachea, bronchi, and lungs), and a dorsal portion (primordium of the oropharynx and esophagus).

44
Q
  1. A 32-year-old patient has a tension pneumothorax that can be treated with needle aspiration. To avoid an injury of the intercostal neurovascular bundle, the needle may be inserted in which of the following locations?
    (A) Above the upper border of the ribs
    (B) Deep to the upper border of the ribs
    (C) Beneath the lower border of the ribs
    (D) Between the external and internal
    intercostals
    (E) Through the transversus thoracis muscle
A

A. The intercostal veins, arteries, and nerves run in the costal groove beneath the inferior border of the ribs between the internal and innermost layers of muscles. The transversus thoracis muscles are situated in the internal surface of the lower anterior thoracic wall.

45
Q
45. A 9-month-old girl was admitted to the children’s hospital with tachypnea (fast breathing) and shortness of breath. Physical examination further exhibits tachycardia (fast heart rate), a bounding peripheral pulse, and her angiographs reveal a patent ductus arteriosus. Which of the following embryonic arterial structures is most likely responsible for the origin of the pat- ent ductus arteriosus?
(A) Right fourth arch
(B) Left fifth arch
(C) Right fifth arch
(D) Left sixth arch
(E) Right sixth arch
A

D. The left sixth aortic arch is responsible for the development of both the ductus arteriosus and the pulmonary arteries. The ductus arteriosus closes functionally in an infant soon after birth, with anatomic closure requiring several weeks.

46
Q
46. A 7-day-old baby is diagnosed as having congenital neonatal emphysema, which is caused by collapsed bronchi because of failure of bronchial cartilage development. Bronchial cartilages are derived from which of the follow- ing derivations?
(A) Ectoderm
(B) Mesoderm
(C) Endoderm
(D) Proctodeum
(E) Neuroectoderm
A

B. Bronchial cartilages, smooth muscles, and connective tissue are derived from the mesoderm. The bronchial epithelium and glands are derived from the endoderm.

47
Q
  1. Stenosis of which structure may produce left ventricular hypertrophy?
A

C. Stenosis of the ascending aorta results in left ventricular hypertrophy.

48
Q
  1. Which structure is most likely to be removed by a pulmonary surgeon in a surgical resection of a lobe (lobectomy) to remove lung cancer in the apex of the right lung?
A

B. During surgical treatment for cancer in the apex of the right lung by a lobectomy, the right superior secondary (eparterial) bronchus should be removed.

49
Q
  1. Which structure branches into the bronchial arteries?
A

E. The right and left bronchial arteries arise from the descending (thoracic) aorta.

50
Q
  1. Into which structure does the azygos vein drain venous blood?
A

A. The azygos vein drains venous blood into the SVC.

51
Q
  1. The left coronary artery arises from which structure?
A

C. The right and left coronary arteries arise from the ascending aorta.

52
Q
  1. Which structure is crossed superiorly by the aortic arch and left pulmonary artery?
A

D. The left primary bronchus is crossed superiorly by the arch of the aorta and the pulmonary artery.

53
Q

Can be removed in a surgical resection of a lobe to remove lung cancer on the diaphragmatic surface?

A

B. The right inferior lobar bronchus may be removed in a surgical resection of the inferior lobe of the right lung that is in contact with the diaphragm.

54
Q
  1. Becomes hypertrophied as result of the pulmonary stenosis?
A

C. Pulmonary stenosis results in right ventricular hypertrophy.

55
Q
  1. Receives oxygenated blood via pulmonary

veins?

A

E. The left atrium receives oxygenated blood from the lung by way of the pulmonary veins.

56
Q
  1. Lies on the right side of the aortic arch and ascending aorta?
A

A. The SVC lies on the right side of the ascending aorta and the arch of the aorta.

57
Q
  1. Contains the septomarginal trabecula?
A

C. The right ventricle contains the septomarginal trabecula.

58
Q
  1. Takes its origin from the left ventricle and

ends at the sternal angle?

A

D. The ascending aorta takes its origin from the left ventricle and ends at the level of the sternal angle by becoming the arch of the aorta.