Block 3 Anat Thorax
- 1.
A 32-year-old patient who weighed 275 pounds came to doctor's office. On the surface of the chest, a physician was 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
Correct Answer
C. In the left fifth intercostal spaceExplanation
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.Rate this question:
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- 2.
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 following 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
Correct Answer
A. Elastic tissue in the lungs and thoracic wallExplanation
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.Rate this question:
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- 3.
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 preganglionic sympathetic fibers
- B.
General visceral afferent (GVA) and postganglionic sympathetic fibers
- C.
GVA and preganglionic sympathetic fibers
- D.
General somatic efferent (GSE) and postganglionic sympathetic fibers
- E.
GVA and GSE fibers
Correct Answer
C. GVA and preganglionic sympathetic fibersExplanation
The greater splanchnic nerves contain general visceral afferent (GVA) and
preganglionic sympathetic general visceral efferent (GVE) fibers.Rate this question:
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- 4.
A 17-year-old boy was involved in gang fighting 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
Correct Answer
D. Dorsal root ganglion and lateral horn of the spinal cordExplanation
The white rami communicantes contain preganglionic sympathetic general visceral
efferent (GVE) fibers and general visceral afferent (GVA) fibers whose cell bodies are located in
the lateral horn of the spinal cord and the dorsal root ganglia. The sympathetic chain ganglion contains
cell bodies of the postganglionic sympathetic nerve fibers. 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.Rate this question:
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- 5.
A 27-year-old cardiac patient with an irregular heartbeat visited 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 midclavicular line
- E.
Over the right half of the lower end of the body of the sternum
Correct Answer
D. In the left fifth intercostal space at the midclavicular lineExplanation
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 intercostals space,
the aortic valve is most audible over the medial end of the second right intercostals space, and the
right AV valve is most audible over the right half of the lower end of the body of the sternum.Rate this question:
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- 6.
A 19-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
Correct Answer
B. Middle cardiac veinExplanation
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.Rate this question:
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- 7.
A 37-year-old patient with palpitation was examined by her physician, and one of the diagnostic records included a posterior-anterior chest x-ray film. Which of the following comprise 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
Correct Answer
D. Right ventricleExplanation
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.Rate this question:
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- 8.
A 7-year-old boy has a damaged interventricular septum. Which of the following valves is most likely defective?
- A.
Pulmonary valve
- B.
Mitral valve
- C.
Valve of coronary sinus
- D.
Tricuspid valve
- E.
Aortic valve
Correct Answer
D. Tricuspid valveExplanation
The septal cusp of the tricuspid valve is attached by a cordae tendineae to
the septal papillary muscle, which arises from the interventricular septum. Other valves are not
associated with the interventricular (IV) septum.Rate this question:
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- 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
Correct Answer
C. Sinoatrial (SA) nodeExplanation
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 atrioventricular (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.Rate this question:
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- 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 bronchopulmonary 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
Correct Answer
A. Medial and lateralExplanation
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.Rate this question:
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- 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
Correct Answer
C. Right superior bronchusExplanation
The eparterial bronchus is the right superior lobar (secondary) bronchus;
all of the other bronchi are hyparterial bronchiRate this question:
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- 12.
An 83-year-old man with a typical coronary 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
Correct Answer
D. Posterior part of the left ventricleExplanation
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.Rate this question:
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- 13.
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 general somatic efferent fibers
- B.
Difficulty in expiration
- C.
Loss of sensation in the pericardium and mediastinal pleura
- D.
Normal function of the diaphragm
- E.
Loss of sensation in the costal part of the diaphragm
Correct Answer
C. Loss of sensation in the pericardium and mediastinal pleuraExplanation
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 general visceral efferent
(GVE) (postganglionic sympathetic) fibers. The costal part of the diaphragm receives GSA fibers
from the intercostal nerves.Rate this question:
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- 14.
An 8-year-old boy with atrial septal defect 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
Correct Answer
D. Anterior cardiac veinExplanation
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.Rate this question:
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- 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 circumflex branch?
- A.
Tricuspid valve insufficiency
- B.
Mitral valve insufficiency
- C.
Ischemia of atrioventricular (AV) node
- D.
Paralysis of pectinate muscle
- E.
Necrosis of septomarginal trabecula
Correct Answer
B. Mitral valve insufficiencyExplanation
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 pectinate muscles, tricuspid valve, and septomarginal trabecula
are present in the right atrium and ventricle.Rate this question:
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- 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
Correct Answer
D. Superior lobe of the left lungExplanation
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.Rate this question:
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- 17.
A thoracentesis is performed to aspirate an abnormal accumulation of fluid in a 37-yearold 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 2 and 4
- B.
Ribs 4 and 6
- C.
Ribs 6 and 8
- D.
Ribs 8 and 10
- E.
Ribs 10 and 12
Correct Answer
D. Ribs 8 and 10Explanation
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, therefore between ribs 8 and 10. Other intercostals spaces are not preferred.Rate this question:
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- 18.
A 6-year-old boy with tetralogy of Fallot shows the pulmonary stenosis and the right ventricular hypertrophy in addition to other symptoms. Which of the following structures is likely found in the hypertrophied heart chamber?
- A.
Sinus venarum
- B.
Crista terminalis
- C.
Pectinate muscles
- D.
Septomarginal trabecula
- E.
Valve of the coronary sinus
Correct Answer
D. Septomarginal trabeculaExplanation
The right ventricle contains the septomarginal trabecula, which forms a
bridge between the interventricular septum and the base of the anterior papillary muscle. The sinus
venarum, crista terminalis, pectinate muscles, and valve of the coronary sinus are found in
the right atrium.Rate this question:
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- 19.
A 33-year-old patient is suffering from a sudden occlusion at the origin of the descending (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 nine posterior
Correct Answer
E. Lower nine posteriorExplanation
The first two posterior intercostal arteries are branches of the highest (superior)
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 seventh, eighth, and ninth intercostal spaces and ends in the tenth intercostal
space where it anastomoses with the deep circumflex iliac artery.Rate this question:
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- 20.
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
Correct Answer
C. Anterior interventricular arteryExplanation
The apex of the heart typically receives blood from the anterior interventricular
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.Rate this question:
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- 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 are characteristics of the cancerous lung?
- A.
Horizontal fissure
- B.
Groove for superior vena cava
- C.
Middle lobe
- D.
Lingula
- E.
Larger capacity than the right
Correct Answer
D. LingulaExplanation
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, and middle lobe and
has a larger capacity than the left lung.Rate this question:
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- 22.
An 18-year-old girl is thrust into the steering wheel while driving. 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
Correct Answer
E. Muscles of the abdominal wallExplanation
The abdominal muscles are the major muscles of expiration, whereas the
other distractors are muscles of inspirationRate this question:
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- 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
Correct Answer
E. Hemiazygos veinExplanation
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.Rate this question:
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- 24.
A 46-year-old patient comes to his doctor's office and complains of chest pain and headache. 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
Correct Answer
B. Arch of the azygos veinExplanation
The azygos vein arches over the root of the right lung and empties into the
superior vena cava. Other veins do not pass over the root of the right lung.Rate this question:
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- 25.
A 21-year-old patient with a stab wound reveals a laceration of the right vagus nerve near the trachea in the superior mediastinum. Which of the following conditions would most likely be resulted from this lesion?
- A.
Loss of sensation carried by the recurrent laryngeal nerve
- B.
Vasodilation of coronary arteries
- C.
Dilation of the bronchial lumen
- D.
Increase in cardiac rate
- E.
Injury to parasympathetic preganglionic fibers
Correct Answer
E. Injury to parasympathetic preganglionic fibersExplanation
The vagus nerve carries parasympathetic preganglionic fibers to the thoracic
and abdominal viscera. The right recurrent laryngeal nerve is not affected by this injury because
it winds around the right subclavian artery and ascends in the neck. The parasympathetic nerve
in the vagus nerve decreases the heart rate, constricts the bronchial lumen, and causes vasoconstriction
of the coronary arteries.Rate this question:
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- 26.
A 5-year-old boy with breathing difficulty, chest pain, and cough was admitted to a local hospital. The pediatrician who examined the boy, along with laboratory results, diagnosed the child as having cystic fibrosis. Which of the following structures is most likely blocked?
- A.
Trachea
- B.
Primary bronchus
- C.
Secondary or lobar bronchi
- D.
Terminal bronchioles
- E.
Alveolar duct
Correct Answer
E. Alveolar ductExplanation
Cystic fibrosis affects the respiratory system by causing an excess production
of viscous mucus by the bronchial glands, followed by mucous plugging and obstruction of
the respiratory airway, particularly a small airway, such as that in a child. The alveolar duct is a
part of this respiratory unit. The other structures are not affected because they are large airway
and are not usually obstructed and thus do not help in making the diagnosis.Rate this question:
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- 27.
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 atrioventricular (AV) opening
- C.
Improper closing of the pulmonary valves
- D.
An abnormally large right AV opening
- E.
Stenosis of the aorta
Correct Answer
E. Stenosis of the aortaExplanation
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.Rate this question:
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- 28.
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 one
- B.
Often receives more foreign bodies than the right one
- C.
Gives rise to the eparterial bronchus
- D.
Is longer than the right primary bronchus
- E.
Runs under the arch of the azygos vein
Correct Answer
D. Is longer than the right primary bronchusExplanation
The right primary bronchus is shorter than the left one and has a larger diameter.
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 bronchusRate this question:
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- 29.
A 62-year-old woman who is a heavy smoker has an advanced lung cancer that spread into her right third intercostal space posterior to the midaxillary line. If cancer cells are carried in the venous drainage, they would travel first to which of the following veins?
- A.
Superior vena cava
- B.
Right superior intercostal vein
- C.
Right brachiocephalic vein
- D.
Azygos vein
- E.
Hemiazygos vein
Correct Answer
B. Right superior intercostal veinExplanation
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 superior vena cava. The hemiazygos
vein usually drains into the azygos vein.Rate this question:
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- 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.
Superior vena cava
- D.
Ascending aorta
- E.
Left ventricle
Correct Answer
C. Superior vena cavaExplanation
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
superior vena cava, 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.Rate this question:
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- 31.
A 37-year-old man is brought to the emergency room complaining of severe chest pain. His angiogram reveals thromboses of both brachiocephalic veins. 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
Correct Answer
D. Left superior intercostalExplanation
The left superior intercostal vein is formed by the second, third, and fourth
posterior intercostal vein and drains into the left brachiocephalic vein. The right superior intercostal
vein drains into the azygos vein, which in turn drains into the superior vena cava. The
hemiazygos vein drains into the azygos vein, whereas the internal thoracic vein empties into the
brachiocephalic vein.Rate this question:
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- 32.
A cardiologist is on clinical rounds with her medical students. She asks them, "During the cardiac cycle, which of the following events occurs?"
- A.
Atrioventricular (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
Correct Answer
D. Blood flow in coronary arteries is maximal during diastoleExplanation
During diastole the atrioventricular (AV) valves open and the aortic and
pulmonary valves close, whereas during systole the AV valves close and the aortic and pulmonary
valves open.Rate this question:
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- 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
Correct Answer
E. Left atrium and ventricleExplanation
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.Rate this question:
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- 34.
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
Correct Answer
A. Bifurcation of the tracheaExplanation
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.Rate this question:
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- 35.
A 37-year-old house painter fell from a ladder and fractured his left third rib and 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
Correct Answer
B. Body of the second thoracic vertebraExplanation
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.Rate this question:
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- 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
Correct Answer
B. Descending aortaExplanation
The descending aorta is found in both the superior and posterior mediastina.
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.Rate this question:
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- 37.
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
Correct Answer
D. Left fifth intercostal spaceExplanation
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 spacesRate this question:
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- 38.
The attending faculty in the coronary intensive care unit (ICU) 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
Correct Answer
C. Tricuspid and mitralExplanation
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.Rate this question:
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- 39.
A 27-year-old patient with Marfan's 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
Correct Answer
D. Left recurrent laryngeal nerveExplanation
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.Rate this question:
-
- 40.
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 sinoatrial node
- D.
Receives the right pulmonary vein
- E.
Is hypertrophied by pulmonary stenosis
Correct Answer
C. Contains the sinoatrial nodeExplanation
The sinoatrial (SA) and atrioventricular (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.Rate this question:
-
- 41.
A 57-year-old patient has a heart murmur resulting from the inability to maintain constant tension on the cusps of the atrioventricular (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
Correct Answer
C. Chordae tendineaeExplanation
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.Rate this question:
-
- 42.
A 52-year-old patient with a history of myocardial infarction exhibits a right coronary artery that is blocked by a fat globule after giving off the right marginal artery. Which of the following structures may have oxygen deficiency?
- A.
Right atrium
- B.
Sinoatrial (SA) node
- C.
Atrioventricular (AV) node
- D.
Apex of the heart
- E.
Anterior interventricular septum
Correct Answer
C. Atrioventricular (AV) nodeExplanation
The atrioventricular (AV) node is supplied by the AV nodal artery, which
usually arises from the right coronary artery opposite the origin of the posterior interventricular
branch. The right atrium receives blood from the right coronary artery, the sinoatrial (SA) node
is supplied by the sinuatrial node artery, and the apex of the heart and AV septum are supplied
by the anterior IV artery.Rate this question:
-
- 43.
A surgical resident inadvertently ligates the phrenic nerve instead of the accompanying artery descending between the mediastinal pleura and the pericardium without causing any particular harm. Which of the following arteries did he intend to ligate?
- A.
Internal thoracic
- B.
Musculophrenic
- C.
Pericardiacophrenic
- D.
Right coronary artery
- E.
Superior (supreme) thoracic
Correct Answer
C. PericardiacophrenicExplanation
The phrenic nerve is accompanied by the pericardiacophrenic vessels of the
internal thoracic vessels and descends between the mediastinal pleura and the pericardium to
supply the pericardium, the mediastinal and diaphragmatic pleura, and the diaphragm. The internal
thoracic artery descends directly behind the first six costal cartilages, just lateral to the sternum.
The musculophrenic artery follows the costal arch on the inner surface of the costal cartilages.
The right coronary artery runs between the right auricle and the pulmonary trunk and then
descends in the coronary sulcus between the right atrium and ventricle. The superior thoracic artery
arises from the axillary artery and supplies the anterior first two intercostals space.Rate this question:
-
- 44.
A pulmonary fellow at a university hospital is asked to consult on a patient in respiratory failure. When the diaphragm contracts, which of the following conditions should normally occur?
- A.
Decreased thoracic volume
- B.
Increased abdominal volume
- C.
Increased lung volume
- D.
Air flow out of the bronchi
- E.
Increased thoracic pressure
Correct Answer
C. Increased lung volumeExplanation
During inspiration the diaphragm contracts, increasing the vertical diameter
of the thorax and hence increasing lung volume, thoracic volume, and air flow into the
bronchi, and decreasing intrathoracic and intrapulmonary pressures and abdominal volume.Rate this question:
-
- 45.
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
Correct Answer
A. Above the upper border of the ribsExplanation
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.Rate this question:
-
Quiz Review Timeline +
Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.
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Current Version
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Mar 20, 2023Quiz Edited by
ProProfs Editorial Team -
Nov 10, 2011Quiz Created by
Chachelly
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