Thorax

Question 1

37. The following statements concerning the right tracheo-bronchial lymph nodes are correct except which?
    A. They could become enlarged as the result of invasion of malignant tumor cells from middle lobe of the right lung
    B. They could become enlarged as the result of invasion of malignant tumor cells from the inferior lobe of the right lung
    C. They are situated alongside the trachea and the bronchi
    D. They drain lymph node from the lower end of the trachea
    E. They do not drain lymph from the heart

Answer 1

E

Question 2

38. The following structures may prrss against esophagus during the passage of a barium meal except which?
    A. Left ventricle
    B. Left principal bronchus and aorta
    C. Margins of the esophageal opening in the diaphragm
    D. Muscular fibers of the lower end of the pharynx
    E. Left atrium

Answer 2

A

Question 3

39. The following statements concerning coarctation (narrowing) of the aorta are correct except which?
    A. The third to the eleventh posterior intercostal arteries have diminished blood flow
    B. The first and second posterior intercostal arteries will
    C. The narrowing of the aorta lies just proximal, opposite, or distal to the site of the attachment of the ligamentum arteriosum
    D. The narrowing takes place after birth
    E. The condition is thought to resilt from contraction of ductus arteriosus muscle tissu

Answer 3

B. The first and second posterior intercostal arteries are branches of the superior intercostal artery, ehich in turn is a branch of the subclavian artery. The subclavian arteries arise proximal to the obstruction and are therefore unaffected

Question 4

40. The following statements concerning an intercostal space are correct except which?
    A. The anterior intercostal arteries of the lower five intercostal spaces are branches of the musculophrenic artery.
    B. The sensory fibers in the lower five intercostal
    nerves supply the skin of the lateral thoracic and anterior abdominal walls.
    C. The posterior intercostal arteries of the lower nine
    spaces are branches of the thoracic aorta.
    D. Throughout an intercostal space, the intercostal nerves and blood vessels lie close to the upper border of the lower rib.
    E. The intercostal nerves and blood vessels run be-
    tween the internal and the innermost intercostal muscles.

Answer 4

D. The intercostal nerves and blood vessels run forward in the subcostal groove of the upper rib in the intercostal space. They are arranged from above downward as follows: vein, artery, and nerve.

Question 5

41. The following statements concerning the positions of thoracic structures at different phases of respiration are correct except which?
    A. The trachea bifurcates opposite the manubriosternal angle in the midrespiratory position.
    B. On full inspiration, the lower margin of the left lung could extend down the midclavicular line to the
    eighth costal cartilage.
    C. The lower margin of the right lung in the midclavicular line could cross the sixth rib in the midrespiratory position.
    D. The apex of the heart can usually be felt in the
    sixth left intercostal space in the midrespiratory
    position.
    E. On full expiration the right dome of the diaphragm
    may extend up as far as or beyond the upper border of the fifth rib.

Answer 5

D. The apex of the heart can usually be felt in the fifth left intercostal space 3.5 in. (9 cm) from the midline.

Question 6

42. The following statements concerning the heart are cor- rect except which?
    A. The first sound of the heart is lu ̄b and is produced by
    the contraction of the ventricles and the closure of
    the tricuspid and mitral valves.
    B. The second shorter sound of the heart is du ̆ p, which
    is produced by the sharp closure of the aortic and
    pulmonary valves.
    C. The pulmonary valve has two semilunar cusps.
    D. The left atrium lies posterior to the right atrium.
    E. The apex beat of the heart is best felt by asking the
    patient to sit up and lean forward.

Answer 6

C. The pulmonary valve guards the pulmonary orifice and has three semilunar cusps attached by their curved lower margins to the arterial wall.

Question 7

43. The following statements concerning the structure of
    the heart are correct except which?
    A. The trabeculae carneae are internal surface structures of both the left and the right ventricles.
    B. The pericardial cavity is the potential space be-
    tween the fibrous and the serous pericardia.
    C. The coronary arteries are functional end arteries.
    D. The sinuatrial node is supplied by the right and sometimes the left coronary artery.
    E. The four pulmonary veins open through the posterior wall of the left atrium and there are no valves

Answer 7

B. The pericardial cavity lies between the parietal and visceral layers of the serous pericardium.

Question 8

44. The following statements regarding the innervation of thoracic structures are correct except which?
    A. The lung and visceral pleura are innervated by the
    autonomic nerves and are not sensitive to sensations of temperature, touch, and pressure.
    B. The motor innervation of the diaphragm is provided by the third, fourth, and fifth cervical spinal nerves
    and by the lower six intercostal nerves.
    C. The sensory nerve supply to the mucous membrane of the lower part of the trachea is from the vagus and
    the recurrent laryngeal nerves.
    D. The nerve supply of the pericardium is the phrenic
    nerves.
    E. The sinuatrial node is supplied by sympathetic and
    parasympathetic nerves via the cardiac plexuses.

Answer 8

B. The motor innervation of the diaphragm is sup- plied only by the phrenic nerve (C3–5).

Question 9

45. The following statements concerning thoracic structures are correct except which?
    A. The carina is the name given to the site of bifurcation of the trachea.
    B. The ligamentum arteriosum is the remains of the
    ductus arteriosus.
    C. The ductus arteriosus is formed from the sixth left
    pharyngeal arch.
    D. The thymus lies in the middle mediastinum.
    E. The thymus receives its arterial supply mainly
    from the internal thoracic arteries.

Answer 9

D. The thymus lies in the superior mediastinum and when enlarged may extend into the neck

Question 10

46. The following events occur on inhalation except which?
    A. The diaphragm descends.
    B. The external intercostal muscles contract.
    C. The abdominal muscles contract and push the abdominal viscera cranially.
    D. The ribs are raised.
    E. The vertical dimension of the thoracic cavity increases.

Answer 10

C. On inspiration, the abdominal muscles relax to accommodate the abdominal viscera as the diaphragm descends.

Question 11

47. When passing a needle through the chest wall and into the pleural cavity in the midaxillary line, the following structures will be pierced except which?
A. The external intercostal muscle
B. The skin
C. The parietal pleura
D. The levator costarum
E. The internal intercostal muscle

Answer 11

D. The levator costarum muscles are small accessory muscles of inspiration found on the back of the chest wall alongside the vertebral column.

Question 12

48. The following statements concerning the bronchopulmonary segments are correct except which?
    A. It is a subdivision of a lung lobe.
    B. It is pyramidal in shape, with its apex toward the
    lung surface.
    C. It is surrounded by connective tissue.
    D. It has a segmental bronchus, a segmental artery,
    lymph vessels, and autonomic nerves.
    E. When diseased, it can be removed surgically as a
    structural unit.

Answer 12

B. The apex of the pyramidal-shaped bronchopulmonary segment points toward the lung root.

Question 13

49. The following statements concerning the main bronchi are correct except which?
    A. The right main bronchus is wider than the left main
    bronchus.
    B. The right main bronchus is shorter than the left main
    bronchus.
    C. The right main bronchus is more vertical in position
    than the left main bronchus.
    D. The left main bronchus passes to the left in front of
    the esophagus.
    E. The left main bronchus gives off the superior lobar
    bronchus before entering the hilum of the lung.

Answer 13

E. The right principal (main) bronchus gives off the superior lobar bronchus before entering the hilum of the right lung. The left principal bronchus gives off the superior lobar bronchus after entering the left lung.

Question 14

50. The following statements concerning the diaphragm are correct except which?
    A. The diaphragm is a thin musculotendinous sheet
    that can be ruptured by extreme pressure applied
    from below.
    B. On contraction, the diaphragm increases the intrathoracic pressure.
    C. The right crus provides a sphincter-like mechanism
    for the esophagus.
    D. On contraction, the diaphragm assists in the return
    of venous blood to the right atrium and of lymph to
    the thoracic duct.
    E. When viewed from in front, the central tendon of
    the diaphragm lies behind the xiphisternal joint.

Answer 14

B. On contraction, the diaphragm descends and thus increases the vertical diameter of the thoracic cavity and reduces the intrathoracic pressure.

Question 15

51. The following statements concerning the lungs are correct except which?
    A. Each lung is very elastic, and should the thoracic
    cavity be opened by a stab wound, the lung shrinks
    to one third or less in volume.
    B. The cardiac notch lies in the lower lobe of the left
    lung.
    C. The visceral pleura covering each lung lines the fissures that are situated between the lobes.
    D. The apex of each lung extends up into the root of
    the neck and lies anterior to the lower roots of the
    brachial plexus.
    E. The bronchi, connective tissue, and visceral pleura
    of the lungs are supplied by the bronchial arteries.

Answer 15

B. The cardiac notch of the left lung lies in the upper lobe.

Question 16

52. With aging, the following detrimental changes occur in the thorax except which?
    A. The ribs and the costal cartilages become more
    rigid .
    B. The elastic tissue in the lungs tends to degenerate.
    C. The manubriosternal joint becomes more mobile.
    D. The thoracic and the abdominal muscles tend to
    atrophy.
    E. The xiphoid process becomes ossified.

Answer 16

C. The manubriosternal joint becomes less mobile with age. Eventually, the manubrium becomes joined with the body of the sternum by bone.

Question 17

53. The following anatomic events occur at the level of the sternal angle (angle of Louis) except which?
    A. The right and the left pulmonary arteries enter the
    lungs.
    B. The right recurrent laryngeal nerve arises from the
    right vagus nerve.
    C. The trachea bifurcates.
    D. The ascending aorta becomes continuous with the arch of the aorta.
    E. The second costal cartilages articulate with the sternum

Answer 17

B. At the level of the sternal angle, the left recurrent laryngeal nerve arises from the left vagus nerve, hooks beneath the arch of the aorta, and ascends to the neck. The right recurrent laryngeal nerve arises from the right vagus nerve in the neck and hooks beneath the right subclavian artery; the right recurrent laryngeal nerve does not enter the thorax.

Question 18

54. The following structures open into the right atrium except which?
A. The superior vena cava
B. The coronary sinus
C. The anterior cardiac vein
D. The inferior vena cava
E. The right pulmonary veins

Answer 18

E. By entering the left atrium, the two right pulmonary veins and the two left pulmonary veins return oxygenated blood to the heart.

Question 19

55. The conducting system of the heart is composed of the following structures except which?
A. The Purkinje plexus
B. The deep cardiac plexus
C. The sinuatrial node
D. The atrioventricular bundle
E. The atrioventricular node

Answer 19

B. The deep cardiac plexus is an autonomic nerve plexus that lies outside the heart and below the arch of the aorta.

Question 20

56. The following anatomic facts regarding the right coronary artery are correct except which?
    A. It gives rise to a marginal branch.
    B. It passes forward between the right auricle and the
    pulmonary trunk.
    C. It gives rise to an anterior interventricular branch.
    D. It arises from the anterior aortic sinus.
    E. It descends in the right atrioventricular groove.

Answer 20

C. The anterior interventricular artery is a branch of the left coronary artery.

Question 21

57. During fetal life, the following facts regarding the circulatory system are correct except which?
    A. The blood passing through the foramen ovale is
    more oxygenated than that passing through the right
    atrioventricular orifice.
    B. The direction of blood flow through the ductus arteriosus is from right to left.
    C. The ductus venosus permits blood to bypass the
    liver.
    D. The blood in the abdominal aorta is relatively more
    oxygenated than that in the internal carotid arteries.
    E. The valve of the inferior vena cava deflects blood toward the foramen ovale.

Answer 21

D. The most richly oxygenated blood reaches the brain via the internal carotid arteries. The abdominal aorta contains blood from the right ventricle, the pulmonary trunk, and the ductus arteriosus; but this blood is poorly oxygenated.

Question 22

58. Pain arising in the heart is commonly referred to the following skin areas except which?
A. Up into the neck and jaw
B. Down the medial side of the arm
C. The point of the shoulder
D. The epigastric area
E. Over the sternum

Answer 22

C. Pain arising from the myocardium ascends to the central nervous system through the cardiac branches of the sympathetic trunk and enters the spinal cord through the posterior roots of the upper four thoracic nerves. This pain is not felt in the heart; rather, it is referred to the skin areas sup- plied by the upper four intercostal nerves and by the intercostobrachial nerve (T2). The intercosto- brachial nerve communicates with the medial cu- taneous nerve in the upper part of the arm. A certain amount of spread of nervous information occurs within the central nervous system, because the pain is sometimes felt in the neck, the jaw, and the epigastrium, Cardiac pain is not referred to the point of the shoulder.

Question 23

A patient is examined in the standing position with a left-sided pleurisy.

59. Where would you expect the pleural fluid to gravitate down to?
A. The oblique fissure 
B. The cardiac notch
C. The costomediastinal recess 
D. The costodiaphragmatic recess 
E. The horizontal fissure

Answer 23

D. The costodiaphragmatic recess is the most dependent part of the pleural cavity.

Question 24

A patient was seen in the Emergency Department in cardiac arrest.

60. During cardiopulmonary resuscitation the posterior surface of the heart was compressed by which of the following structures?
A. The body of the sternum
B. The heads of the ribs
C. The tracheal bifurcation
D. The inferior vena cava
E. The bodies of the vertebrae

Answer 24

E.

Question 25

A patient was admitted into hospital with acute pericarditis. Because the movements of the heart were compromised by the excess of fluid in the pericardial cavity, and the cause of the infection was unknown, it was decided to perform a pericardiocentesis. A specimen of the fluid was kept for bacteriological examination.

61. Pericardiocentesis is best performed by passing a needle through
    A. the fourth intercostal space.
    B. the sixth intercostal space at the left paravertebral
    border.
    C. the second intercostal space at the midclavicular
    line.
    D. the subcostal angle.
    E. the second intercostal space at the right sternal
    angle.

Answer 25

D. Pericardial fluid may be aspirated from the pericardial cavity by inserting the needle to the left of the xiphoid process in an upward and backward direction at a 45° angle to the skin. Because of the cardiac notch, the needle misses the pleura and the lungs, and it pierces the pericardium.

Question 26

A patient was seen in the emergency department with a myocardial infarction. After a thorough clinical examination, including an electrocardiogram, it was concluded that the anterior interventricular branch of the left coronary artery was occluded.

62. From the areas of the heart listed below select the one most likely to be involved.
    A. The entire diaphragmatic surface of the left ventricle
    B. The anterior part of the ventricular septum and
    the anterior (septal) papillary muscle of the left
    ventricle
    C. The posterior wall of the right atrium
    D. The atrioventricular bundle
    E. The right auricle

Answer 26

B. The diaphragmatic surface of the left ventricle receives its blood supply from the posterior interventricular branch of the right coronary artery as well as from the anterior interventricular branch of the left coronary artery. The posterior wall of the right atrium, the right auricle, and the atrioventricular bundle are all supplied by the right coronary a rte ry.

Question 27

A4-year-old boy with cyanosis was examined by a pediatrician. The child had apparently become cyanotic during his 1st year of life. Since that time, sudden attacks of breathlessness had occurred on exertion. After a careful workup, a diagnosis of tetralogy of Fallot was made. In this congenital anomaly of the heart there are four cardiac defects.

63. Which of the following is the most characteristic of the condition?
    A. Pulmonary stenosis with hypertrophy of the right ventricle
    B. Large atrial septal defect
    C. Hypertrophy of the left ventricle
    D. Stenos is of the aorta
    E. High blood pressure in the left ventricle

Answer 27

A. The tetralogy of Fallot consists of a large ventricular septal defect, stenosis of the pulmonary trunk, the exit of the aorta immediately above the ventricular septal defect, and right ventricular hyper- trophy secondary to the ventricular septal defect and the pulmonary stenosis. The pulmonary steno- sis results in an impaired pulmonary circulation, with consequent poor oxygenation of the blood. It is not surprising, that the increased oxygen needed on exertion produces excessive breathlessness.

Question 28

A 22-year-old man was seen in the emergency department after a street shootout. The patient showed signs of severe hemorrhagic shock. A small entrance wound was found in the third left intercostal space approximately 1 in. (2.5 cm) from the lateral margin of the sternum, but there was no exit wound. The left side of his thorax was dull on percussion, and breath sounds were absent on that side of the chest. It was decided to open the chest (thoracotomy) through the fourth left intercostal space, after which it was found that the left atrium had been perforated by the bullet.

64. When the thoracotomy incision was made to enter the pleural cavity, the following structures were incised except for which one?
    A. The skin and subcutaneous tissue
    B. The pectoral muscles and the serratus anterior muscle
    C. The latissimus dorsi muscle
    D. The external intercostal muscle and the anterior
    intercostal membrane
    E. The internal intercostal and innermost intercostal
    muscles
    F. The endothoracic fascia and the parietal pleura

Answer 28

C. The latissimus dorsi is a sheet of muscle that covers the back of the thoracic cage and inserts into the floor of the bicipital groove of the humerus. It is located too far posteriorly to be damaged by this exploratory thoracotomy.

Question 29

65. The following important structures are in the region of
    the thoracotomy incision except which one?
    A. The internal thoracic artery
    B. The intercostal nerve
    C. The superior epigastric artery
    D. The intercostal artery
    E. The intercostal vein

Answer 29

C. The internal thoracic artery terminates in the sixth intercostal space by dividing into the musculophrenic artery and the superior epigastric artery. The superior epigastric artery quickly enters the anterior abdominal wall.

Question 30

A 35-year-old woman was seen in the emergency department after an automobile accident. While driving her car, she had been wearing a lap belt but without the shoulder strap; she hit a utility pole head-on. Examination of the thoracic cage revealed a fracture of the body of the sternum and of the third and the fourth left ribs.
66. In this case, the following structure(s) located behind the body of the sternum and the left ribs could have been injured except which one(s)?
A. The pericardium
B. The right ventricle of the heart
C. The right atrium of the heart
D. The left ventricle of the heart
E. The phrenic nerves
F. The esophagus

Answer 30

F. The heart can be squeezed between the sternum and the vertebral column when the thorax is subjected to a severe frontal impact. The right atrium, the right ventricle, or part of the left ventricle is commonly injured. The pericardium may be punctured by a fractured rib or, rarely, be ruptured by a sudden blow. If pericardial rupture occurs, it tends to take place along the lateral margins with involvement of the phrenic nerves.

Question 31

67. In such an accident, the patient’s age may play a large role in the extent of anatomic injury. Which of the following statements accounting for this fact is likely to be correct?
    A. The increased elasticity of fibrous structures in
    elderly people.
    B. The highly flexible rib cage in children.
    C. The ossification of the xiphoid cartilage that occurs
    with age .

Answer 31

B. The highly flexible rib cage in children makes myocardial bruising a common occurrence.In elderly patients, toughness of the pericardium and diminished elasticity may make rupture more common.