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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

The answer is 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 proc- ess lies at the level of T10 vertebra.

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

 

The answer is A. 

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

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 pre- ganglionic sympathetic fibers

(B) General visceral afferent (GVA) and post- ganglionic sympathetic fibers

(C) GVAandpreganglionicsympatheticfibers

(D) General somatic efferent (GSE) and

postganglionic sympathetic fibers

(E) GVA and GSE fibers

The answer is C.

The greater splanchnic nerves contain general visceral afferent (GVA) and preganglionic sympathetic general visceral efferent (GVE) fibers.

4

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 poste- rior 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

The answer is 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 dorsal root ganglia. The sympathetic chain ganglion contains cell bodies of the postgan- glionic sympathetic 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.

5

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 midclavicular line

(E) Over the right half of the lower end of the body of the sternum

The answer is 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 mid- clavicular 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.

6

A 19-year-old man came to the emer- gency department, and his angiogram exhibited that he was bleeding from the vein that is accompanied by the posterior inter- ventricular 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

The answer is 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 car- diac vein drains directly into the right atrium, and the small cardiac vein is accompanied by the marginal artery.

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 fol- lowing comprises the largest portion of the sternocostal surface of the heart seen on the radiograph?

(A) Left atriumThorax    

(B) Right atrium

(C) Left ventricle

(D) Right ventricle

(E) Base of the heart

The answer is 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.

8

A 5-year-old girl is brought to the emer- gency department because of difficulty breathing (dyspnea), palpitations, and short- ness of breath. Doppler study of the heart reveals an atrial septal defect (ASD). This malformation usually results from incom- plete closure of which of the following embryonic structures?

(A) Ductus arteriosus

(B) Ductus venosus

(C) Sinusvenarum

(D) Foramen ovale

(E) Truncus arteriosus

The answer is D.

An atrial septal defect (ASD) is a congenital defect in the interatrial septum. During partitioning 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.

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 pace- maker?

(A) Atrioventricular (AV) bundle

(B) AV node

(C) Sinoatrial (SA) node

(D) Purkinje fiber

(E) Moderatorband

The answer is 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 myo- cardium 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.

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 fol- lowing 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

The answer is A.

The right middle lobar (secondary) bronchus leads to the medial and lat- eral 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.

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

The answer is C.

The eparterial bronchus is the right superior lobar (secondary) bronchus;

all of the other bronchi are hyparterial bronchi.

12

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 resultinischemiaofwhichofthefollowing 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

The answer is 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.

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 condi- tions 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

The answer is C.

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

14

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

The answer is 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.

15

A 37-year-old patient with severe chest pain, shortness of breath, and congestive heart failure was admitted to a local hospi- tal. His coronary angiograms reveal a throm- bosis in the circumflex branch of the left coronary artery. Which of the following con- ditions could result from the blockage of blood flow in the circumflex branch?

(A) Tricuspid valve insufficiency

(B) Mitral valve insufficiency

(C) Ischemia of AV node

(D) Paralysis of pectinate muscle

(E) Necrosis of septomarginal trabecula

The answer is B.

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

16

A75-year-oldpatienthasbeensuffering 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

The answer is 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.

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) Ribs1and3

(B) Ribs3and5

(C) Ribs5and7

(D) Ribs7and9

(E) Ribs9and11

The answer is 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 intercos- tals spaces are not preferred.

18

A newborn baby is readmitted to the hospital with hypoxia and upon testing is found to have pulmonary stenosis, transpo- sition of the aorta, interventricular septal defect, and hypertrophy of the right ventri- cle. Which of the following is best described by these symptoms?

(A) ASD

(B) Patent ductus anreriosus

(C) Tetralogy of Fallot

(D) Aortic stenosis

(E) Coarctation of the aorta

The answer is C.

Tetralogy of Fallot is a combination of congenital cardiac defects consist- ing of (a) pulmonary stenosis, (b) transposition of the aorta (so that it overrides the ven- tricular 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 sep- tum, 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 orifice, 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.

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 six posterior

The answer is E.

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 inter- costal 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.

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

The answer is C.

The apex of the heart typically receives blood from the anterior interven- tricular 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.

21

A75-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 char- acteristics does the cancerous lung contain?

(A) Horizontal fissure

(B) Groove for superior vena cava (SVC)

(C) Middlelobe

(D) Lingula

(E) Larger capacity than the right

The answer is 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.

22

An 18-year-old girl is thrust into the steering wheel while driving and experi- ences 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

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

23

 A 78-year-old patient presents with an advanced cancer in the posterior mediasti- num. 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

The answer is E.

The hemiazygos vein is located in the posterior mediastinum. The brachi- ocephalic 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.

24

A 46-year-old patient comes to his doc- tor’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) Accessoryhemiazygosvein

The answer is 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

A 21-year-old patient with a stab wound reveals a laceration of the right vagus nerve proximal to the origin of the recurrent laryn- geal 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

The answer is C.

The parasympathetic nerve fibers in the vagus nerve constrict the bron- chial 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

A 5-year-old boy with breathing diffi- culty, chest pain, and cough was admitted to a local hospital. The pediatrician who exam- ined 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

The answer is D.

Cystic fibrosis affects the respiratory system by causing an excess produc- tion of viscous mucus by the bronchial glands, followed by mucous plugging and obstruc- tion of the respiratory airway, particularly a small airway, such as that in a child. The alve- olar duct is a part of this respiratory unit. The other structures are not affected because they are large airways and are not usually obstructed and thus do not help in making the diagnosis.

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 AV opening

(C) Improper closing of the pulmonary valves

(D) An abnormally large right AV opening

(E) Stenosis of the aorta

The answer is E.

Stenosis of the aorta can cause left ventricular hypertrophy. Right ven- tricular hypertrophy may occur as a result of pulmonary stenosis, pulmonary and tricus- pid valve defects, or mitral valve stenosis.

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 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

The answer is D.

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 bronchus.

29

A62-year-oldwomanwhoisaheavy 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) SVC

(B) Right superior intercostal vein

(C) Right brachiocephalic vein

(D) Azygos vein

(E) Hemiazygos vein

The answer is 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

A radiologist examines posterior–ante- rior chest radiographs of a 27-year-old vic- tim of a car accident. Which of the following structures forms the right border of the car- diovascular silhouette?

(A) Arch of the aorta

(B) Pulmonary trunk

(C) SVC

(D) Ascending aorta

(E) Left ventricle

The answer is 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.