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Ministry of Health of Ukraine BUKOVINIAN STATE MEDICAL UNIVERSITY “APPROVED” on methodical meeting of the Department of Anatomy, Topographical anatomy and Operative Surgery “………”…………………….2008 р. (Protocol №……….) The chief of department professor ……………………….……Yu.T.Achtemiichuk “………”…………………….2008 р. METHODICAL GUIDELINES for the 2nd-year foreign students of English-spoken groups of the Medical Faculty (speciality “General medicine”) for independent work during the preparation to practical studies THE THEME OF STUDIES “Topographical anatomy and operative surgery of the lungs and mediastinum” MODULE I Topographical Anatomy and Operative Surgery of the Head, Neck, Thorax and Abdomen Semantic module “Topographical Anatomy and Operative Surgery of the Thorax” Chernivtsi – 2008 1. Actuality of theme: The topographical anatomy and operative surgery of the thorax are very importance, because without the knowledge about peculiarities and variants of structure, form, location and mutual location of their anatomical structures, their agespecific it is impossible to diagnose in a proper time and correctly and to prescribe a necessary treatment to the patient. Surgeons usually pay much attention to the topographo-anatomic basis of surgical operations on the thorax. 2. Duration of studies: 2 working hours. 3. Objectives (concrete purposes): To know the definition of regions of the thorax. To know classification of surgical operations on the thorax. To know the topographical anatomy and operative surgery of the organs of the thoracic cavity. 4. Basic knowledges, abilities, skills, that necessary for the study themes (interdisciplinary integration): The names of previous disciplines 1. Normal anatomy 2. Physiology 3. Biophysics The got skills To describe the structure and function of the different organs of the human body, to determine projectors and landmarks of the anatomical structures. To understand the basic physical principles of using medical equipment and instruments. 5. Advices to the student. 5.1. Table of contents of the theme: The thoracic cavity can be divided into a median partition, called the mediastinum, and the laterally placed pleurae and lungs. Mediastinum The mediastinum is a complex of organs that extends superiorly to the thoracic aperture and inferiorly to the diaphragm. It extends anteriorly to the sternum and posteriorly to the 12 thoracic vertebrae. It contains the remains of the thymus, the heart and large blood vessels, the trachea and esophagus, the thoracic duct and lymph nodes, the vagus and phrenic nerves, and the sympathetic trunks. The mediastinum is divided into superior and inferior mediastina by an imaginary plane passing from the sternal angle anteriorly to the lower border of the body of the 4 th thoracic vertebra posteriorly. The inferior mediastinum is further subdivided into the middle mediastinum, which consists of the pericardium and heart; the anterior mediastinum, which is a space between the pericardium and the sternum; and the posterior mediastinum, which lies between the pericardium and the vertebral column. According to the second classification the mediastinum is subdivided into anterior (in front of tracheal bifurcation) and posterior portions (behind of tracheal bifurcation). Superior Mediastinum (1) Thymus, (2) large veins, (3) large arteries, (4) trachea, (5) esophagus and thoracic duct, and (6) sympathetic trunks. Inferior Mediastinum (1) Thymus, (2) heart within the pericardium with the phrenic nerves on each side, (3) esophagus and thoracic duct, (4) descending aorta, and (5) sympathetic trunks. Pleurae The pleurae and lungs lie on either side of the mediastinum within the chest cavity. Each pleura has two parts: parietal layer, which lines the thoracic wall, covers the thoracic surface of the diaphragm and the lateral aspect of the mediastinum, and extends into the neck; visceral layer, which completely covers the outer surfaces of the lungs and extends into the depths of the interlobar fissures. The two layers become continuous with one another by means of a cuff of pleura that surrounds the structures entering and leaving the lung at the hilum of each lung. The pleural cuff hangs down as a loose fold called the pulmonary ligament. The parietal and visceral layers of pleura are separated from one another by a slit-like space, the pleural cavity. The pleural cavity normally contains the pleural fluid, which permits the two layers to move on each other with the minimum of friction. It is customary to divide the parietal pleura according to the region in which it lies or the surface that it covers. The cervical pleura extends up into the neck. It reaches a level about 2.5-4 cm above the medial third of the clavicle. The costal pleura lines the inner surfaces of the ribs, the costal cartilages, the intercostal spaces, the sides of the vertebral bodies, and the back of the sternum. The diaphragmatic pleura covers the thoracic surface of the diaphragm. The mediastinal pleura covers and forms the lateral boundary of the mediastinum. At the hilum of the lung it is reflected as a cuff around the vessels and bronchi and here becomes continuous with the visceral pleura. The costal and diaphragmatic pleurae are forms the costodiaphragmatic recess. They are slitlike spaces between the costal and diaphragmatic parietal pleurae that are separated only by a capillary layer of pleural fluid. It is the lower area of the pleural cavity into which the lung expands on inspiration. The recess is 5 cm deep in the scapular line posteriorly; 8-9 cm in the midaxillary line; and 2.5-4 cm in the midclavicular line. The costomediastinal recesses are situated along the anterior margins of the pleura. They are slit-like spaces between the costal and mediastinal parietal pleurae that are separated by a capillary layer of pleural fluid. During inspiration and expiration the anterior borders of the lungs slide in and out of the recesses. Nerve supply of the pleura The parietal pleura is sensitive to pain, temperature, touch, pressure and is supplied as follows: the costal pleura is segmentally supplied by the intercostal nerves, the mediastinal pleura is supplied by the phrenic nerve, and the diaphragmatic pleura is supplied over the domes by the phrenic nerve and around the periphery by the lower six intercostal nerves. The visceral pleura covering the lungs receives an autonomic supply from the pulmonary plexus; it is sensitive to stretch but is insensitive to common sensations such as pain and touch. Trachea The trachea is a mobile tube about 13 cm long and 2.5 cm in diameter. It has a fibroelastic wall in which are embedded a series of U-shaped bars of hyaline cartilage that keep the lumen patent. The posterior free ends of the cartilage are connected by smooth muscle, the trachealis muscle. The trachea commences in the neck below the cricoid cartilage of the larynx at the level of the body of the 7th cervical vertebra. It ends below in the thorax at the level of the sternal angle (lower border of the 4th thoracic vertebra) by dividing into the right and left principal (main) bronchi. The bifurcation is called the carina. In deep inspiration the carina descends to the level of the 7th thoracic vertebra. The relations of the trachea in the superior mediastinum of the thorax are as follows: • Anteriorly: The sternum, the thymus, the left brachiocephalic vein, the origins of the brachiocephalic and left common carotid arteries, and the arch of the aorta. • Posteriorly: The esophagus and the left recurrent laryngeal nerve. • Right side: The azygos vein, the right vagus nerve, and the pleura. • Left side: The arch of the aorta, the left common carotid and left subclavian arteries, the left vagus and left phrenic nerves, and the pleura. Nerve supply of the Trachea The nerves are branches of the vagus and the recurrent laryngeal nerves and from the sympathetic trunks; they are distributed to the trachealis muscle and to the mucous membrane lining the trachea. Principal Bronchi The right principal (main) bronchus is wider, shorter, and more vertical than the left and is about 2.5 cm long. Before entering the hilum of the right lung, the principal bronchus gives off the superior lobar bronchus. On entering the hilum it divides into a middle and an inferior lobar bronchus. The left principal (main) bronchus is narrower, longer, and more horizontal than the right and is about 5 cm long. It passes to the left below the arch of the aorta and in front of the esophagus. On entering the hilum of the left lung, the principal bronchus divides into a superior and an inferior lobar bronchus. Lungs Each lung are situated in pleural cavities. The lung is conical, covered with visceral pleura, being attached to the mediastinum only by its root. Each lung has a blunt apex, which projects upward into the neck for about 2.5 cm above the clavicle; a concave base that sits on the diaphragm; a convex costal surface, which corresponds to the concave chest wall; and a concave mediastinal surface, which is molded to the pericardium and other mediastinal structures. At about the middle of this surface is the hilum, a depression in which the bronchi, vessels, and nerves that form the root enter and leave the lung. The anterior border is thin and overlaps the heart; it is here on the left lung that the cardiac notch is found. The posterior border is thick and lies beside the vertebral column. Lobes and Fissures Right Lung The right lung is slightly larger than the left and is divided by the oblique and horizontal fissures into three lobes: the upper, middle, and lower lobes. The oblique fissure runs from the inferior border upward and backward across the medial and costal surfaces until it cuts the posterior border about 6 cm below the apex. The horizontal fissure runs horizontally across the costal surface at the level of the 4th costal cartilage to meet the oblique fissure in the midaxillary line. Left Lung The left lung is divided by a similar oblique fissure into two lobes: the upper and lower lobes. There is no horizontal fissure in the left lung. Bronchopulmonary Segments The bronchopulmonary segments are the anatomic, functional, and surgical units of the lungs. Each segmental bronchus passes to a structurally and functionally independent unit of a lung lobe called a bronchopulmonary segment The main characteristics of a bronchopulmonary segment may be summarized as follows: 1. It is a subdivision of a lung lobe. 2. It is pyramid shaped, with its apex toward the lung root. 3. It is surrounded by connective tissue. 4. It has a segmental bronchus, a segmental artery, lymph vessels, and autonomic nerves. 5. The segmental vein lies in the connective tissue between adjacent bronchopulmonary segments. 6. A diseased segment, because it is a structural unit, can be removed surgically. The bronchi are divided in dichotomous type becoming smaller and more numerous The smallest bronchi divide and give rise to bronchioles, which are less than 1 mm in diameter. Bronchioles possess no cartilage in their walls. The bronchioles then divide and give rise to terminal bronchioles. Gaseous exchange between blood and air takes place in the walls of the respiratory bronchioles. The diameter of a respiratory bronchiole is about 0.5 mm. The respiratory bronchioles end by branching into alveolar ducts that lead into tubular passages with numerous alveolar sacs. The alveolar sacs consist of several alveoli opening into a single chamber. Each alveolus is surrounded by a rich network of blood capillaries. Gaseous exchange takes place between the air in the alveolar lumen through the alveolar wall into the blood within the surrounding capillaries. The main bronchopulmonary segments are as follows: Superior lobe Middle lobe Inferior lobe Superior lobe Inferior lobe Right lung Apical, (2) Posterior, (3) Anterior (4) Lateral, (5) Medial (6) Superior (Apical), (7) Medial Basal, (8) Anterior Basal, (9) Lateral Basal, (10) Posterior Basal Left lung (1) Apical, (2) Posterior, (3) Anterior, (4) Superior Lingular, (5) Inferior Lingular (6) Superior (Apical), (7) Medial Basal, (8) Anterior Basal, (9) Lateral Basal, (10) Posterior Basal The root of the lung is formed of structures that are entering or leaving the lung. It is made up of the bronchi, pulmonary artery and veins, lymph vessels, bronchial vessels, and nerves. The root is surrounded by a tubular sheath of pleura, which joins the mediastinal parietal pleura to the visceral pleura covering the lungs. Blood supply of the Lungs The bronchi, the connective tissue of the lung, and the visceral pleura receive their blood supply from the bronchial arteries, which are branches of the descending aorta. The bronchial veins (which communicate with the pulmonary veins) drain into the azygos and hemiazygos veins. The alveoli receive deoxygenated blood from the terminal branches of the pulmonary arteries. The oxygenated blood leaving the alveolar capillaries drains into the tributaries of the pulmonary veins, which follow the intersegmental connective tissue septa to the lung root. Two pulmonary veins leave each lung root to empty into the left atrium of the heart. Lymph drainage of the Lungs The lymph vessels originate in superficial and deep plexuses; they are not present in the alveolar walls. The superficial (subpleural) plexus lies beneath the visceral pleura and drains over the surface of the lung toward the hilum, where the lymph vessels enter the bronchopulmonary nodes. The deep plexus travels along the bronchi and pulmonary vessels toward the hilum of the lung, passing through pulmonary nodes located within the lung substance; the lymph then enters the bronchopulmonary nodes in the hilum of the lung. All the lymph from the lung leaves the hilum and drains into the tracheobronchial nodes and then into the bronchomediastinal lymph trunks. Nerve supply of the Lungs At the root of each lung is a pulmonary plexus composed of efferent and afferent autonomic nerve fibers. The plexus is formed from branches of the sympathetic trunk and receives parasympathetic fibers from the vagus nerve. The sympathetic efferent fibers produce bronchodilatation and vasoconstriction. The parasympathetic efferent fibers produce bronchoconstriction, vasodilatation, and increased glandular secretion. Afferent impulses derived from the bronchial mucous membrane and from stretch receptors in the alveolar walls pass to the central nervous system in both sympathetic and parasympathetic nerves. Pericardium The pericardium is a fibroserous sac that encloses the heart and the roots of the great vessels. Its function is to restrict excessive movements of the heart and to serve as a lubricated container in which the heart can contract. The pericardium lies within the middle mediastinum, posterior to the body of the sternum and the 2nd to the 6th costal cartilages. Fibrous Pericardium The fibrous pericardium is the strong fibrous part of the sac. It is firmly attached below to the central tendon of the diaphragm. It fuses with the outer coats of the great blood vessels passing through it, namely, the aorta, the pulmonary trunk, the superior and inferior venae cavae, and the pulmonary veins. The fibrous pericardium is attached in front to the sternum by the sternopericardial ligaments. Serous Pericardium (Epicardium) The serous pericardium has parietal and visceral layers. The parietal layer lines the fibrous pericardium and is reflected around the roots of the great vessels to become continuous with the visceral layer of serous pericardium that closely covers the heart. The visceral layer is closely applied to the heart and is often called the epicardium. The slitlike space between the parietal and visceral layers is referred to as the pericardial cavity. Normally, the cavity contains a small amount of tissue fluid, the pericardial fluid, which acts as a lubricant to facilitate movements of the heart. Pericardial Sinuses On the posterior surface of the heart, the reflection of the serous pericardium around the large veins forms a recess called the oblique sinus. Also on the posterior surface of the heart is the transverse sinus, which is a short passage that lies between the reflection of serous pericardium around the aorta and pulmonary trunk and the reflection around the large veins. 5.2. Theoretical questions to studies: 1. 2. 3. 4. 5. 6. The subdivision of the thoracic cavity. The subdivision of mediastinum. The topographical anatomy of the lungs. The topographic anatomy of the bronchi. The blood and nerve supply of the thoracic viscera. Principles of operations on lungs - wound closure of lung, resection of segment, lobectomia, pulmonectomia. 5.3. Materials for self-control: DIRECTIONS: Each question below contains four or five suggested responses. Select the one best response to each question. 1. Knowledge of the lymphatic drainage of the breast is clinically important because of the high incidence of breast tumors. The major pathway of lymphatic drainage from the mammary gland is along lymphatic channels that parallel A subcutaneous venous networks to the contralateral breast and to the abdominal wall B tributaries of the axillary vessels to the axillary nodes C tributaries of the intercostal vessels to the parasternal nodes and posterior mediastinal nodes D tributaries of the internal thoracic (mammary) vessels to the parasternal (internal thoracic) nodes E tributaries of the thoracoacromial vessels to the apical (subclavicular) nodes 2. A patient who has undergone a radical mastectomy with extensive axillary dissection suffers winging of the scapula when the flexed arm is pressed against a fixed object. This indicates injury to which of the following nerves? A Axillary B Long thoracic C Lower subscapular D Supraclavicular E Toracodorsal 3. The second rib or its costal cartilage articulates with all the following structures EXCEPT the A body of the sternum B manubrium C second vertebral body D third vertebral body E transverse process of the second vertebra 4. The “bucket-handlle” movement of the ribs during relaxed expiration involves all the following EXCEPT A decrease of the transverse thoracic diameter B contraction of the internal intercostal muscles C inward rotation of the ribs D movement at the costovertebral joints E untwisting of costal cartilages 5. The “pump-handle” movement (elevation of the sternum) during inspiration involves all the following EXCEPT A increase in the anteroposterior chest diameter B increase in the superior-inferior chest diameter C movement at the costovertebral joints D movement at the sternocostal joints E movement at the sternomanubrial joint 6. Contraction of which of the following muscles contributes to forced inspiration? A External oblique B Internal oblique C Rectus abdominis D Transverse abdomimis E None of the above 7. Gravity assists the inspiratory effort of the diaphragm when a person is A lying prone B lying on the left side C lying on the right side D lying supine sitting 8. All the following correctly describe the phrenic nerve EXCEPT A it is a component of the somatic nervous system B it does not innervate the entire diaphragm C it innervates the diaphragmatic peritoneum D it originates from spinal nerves C3-C5 E it passes through the aortic hiatus 9. All the following statements correctly pertain to the left costodiaphragmatic recess EXCEPT A it accommodates lung tissue during inspiration B it extends below the twelfth rib posteriorly C it is formed by the apposition of diaphragmatic and mediastinal pleura D it is maximal upon forced expiration E it is the most dependent (lowest) part of the pleural cavity when a person is sitting 10. Pain referred to the right side of the neck and extending laterally from the right clavicle to the tip of the right shoulder is most likely to involve the A cervical cardiac accelerator nerves B posterior vagal trunk C right intercostal nerves D right phrenic nerve E right recurrent laryngeal nerve 11. An elderly woman visits the hospital emergency room with the recent onset of grotesque swelling of the right arm, neck, and face. Her right jugular vein is visibly engorged and her right brachial pulse is diminished. On the basis of these signs, her chest x-ray might show A a left cervical rib B a mass in the upper lobe of the right lung C aneurysm of the aortic arch D right pneumothorax E thoracic duct blockage in the posterior mediastinum 12. By following the normal lymphatic drainage pathways of the lungs, cancer in the right lung may metastasize to all the following nodes EXCEPT A right bronchopulmonary lymph nodes B right tracheobronchial lymph nodes C left paratracheal lymph nodes D right paratracheal lymph nodes E right axillary lymph nodes 13. Pulmonary disease sometimes can be localized to a bronchopulmonary segment, in which event segmental resection may be feasible. Characteristics of a bronchopulmonary segment that assist in its surgical definition include all the following EXCEPT A an apex directed toward the hilum of the lung B a central segmental artery C a central tertiary or segmental bronchus D a central vein 14. All the following veins drain into the coronary sinus EXCEPT the A anterior cardiac veins B great cardiac vein C middle cardiac vein D oblique vein of the left atrium E small cardiac vein 15. The major venous return system of the heart, the coronary sinus, empties into the A inferior vena cava B left atrium C right atrium D right ventricle E superior vena cava Questions 16-18 A child suspected of aspirating a small, cloth-covered metal button is seen in the emergency room. Whil77e the child does not complain of pain, there is frequent coughing. 16. Anticipating absence of breath sounds, the examining physician listens with a stethoscope to the right lung. Aspirated small objects tend to lodge in the right inferior lobar bronchus for all the following reasons EXCEPT A the left main stem (primary) bronchus is more horizontal than the right B the right inferior lobar bronchus nearly continues the direction of the trachea C the right lung has no middle lobe D the right main stem (primary) bronchus is of greater diameter than the left 17. The breath sounds appear normal on the right side and, to the surprise of the examining physician, there is absence of breath sounds over the lower lobe of the left lung. A posteroanterior (PA) radiograph confirms that the button is in the left lower lobe bronchus. One probable explanation for the object’s presence in this location is A left diaphragmatic hernia B left pneumothorax C normal anatomy D paralysis of the left hemidiaphragm E situs inversus 18. The afferent nerves from the inferior lobar bronchus that carry the stimulation producing the cough include the A phrenic nerve B spinal nerves Tl through T4 C superior laryngeal nerve D thoracic splanchnic nerves E vagal fibers in the pulmonary plexus Questions 19-21 A 28-year-old woman comes into the emergency room exhibiting dyspnea and mild cyanosis, but no signs of trauma. Her chest x-ray is shown below. 19. The most obvious abnormal finding in this patient’s inspiratory posteroanterior chest x-ray (viewed in the anatomic position) is a A bilateral extension of the pleural cavities above the first rib B Clinically enlarged heart C left pneumothorax (collapsed lung) D paralysis of the left hemidiaphragm E right hemothorax (blood in the pleural cavity) 20. The pronounced mediastinal shift to the right includes all the following structures EXCEPT the A aorta B esophagus C heart D sternum E trachea 21. The structure labeled by the arrow in the x-ray is the A arch of the aorta B auricle of the left atrium C collapsed lung D edge of the manubrium E left main stem bronchus Questions 22-26 A 23-year-old, semiconscious man is brought to the emergency room following an automobile accident. He is tachypneic (breathing rapidly) and cyanotic (blue lips and nail beds). The right lower anterolateral thoracic wall reveals a small laceration and flailing (moving inward as the rest of the thoracic cage expands during inspiration). Air does not appear to move into or out of the wound, and it is assumed that the pleura has not been penetrated. After the patient is placed on immediate positive pressure endotracheal respiration, his cyanosis clears and the abnormal movement of the chest wall disappears. Radiographic examination confirms fractures of the fourth through eighth ribs in the right anterior axillary line and of the fourth through sixth ribs at the right costochondral junction. There is no evidence that bony fragments have penetrated the lungs or of pneumothorax (collapsed lung). 22. In this patient, the initial cyanosis – incomplete oxygenation of the blood owing to perfusion of the right lung without ventilation – is a result of A bilateral inability of the pleural cavities to expand B inability of the right chest wall to expand the thoracic cavity C paralysis of the right hemidiaphragm D paralysis of the thoracic musculature E shunting of all blood through the normal lung 23. The primary action of thoracic cavity enlargement during inspiration can be accomplished by all the following EXCEPT the A diaphragm B external intercostal muscles C interchondral portions of the internal intercostal muscles D sternomastoid muscle E transverse thoracic muscle 24. The small superficial laceration, once it is ascertained that it has not penetrated the pleura, is sutured and the chest bound in bandages; positive pressure endotracheal respiration is maintained. Several hours later, the patient’s cyanosis returns. The right side of the thorax is found to be more expanded than the left, yet moves less during respiration. Chest x-rays are shown below. A negative pressure drain (chest tube) has to be inserted into the pleural space. Effective locations for the drain include the A apex between the clavicle and first rib B costomediastinal recess on the left, adjacent to the xiphoid process C right fourth intercostal space in the midclavicular line (just below the nipple) D right seventh intercostal space in the midaxillary line E right eighth intercostal space in the midclavicular line (about 4 inches below the nipple) 25. One liter of blood is withdrawn from the pleural cavity. The patient’s cyanosis immediately clears and signs of the mediastinal shift disappear. Possible sources of the bleeding that produces the hemothorax include all the following EXCEPT the A intercostal arteries B internal thoracic artery C lateral thoracic artery D musculophrenic artery E vessels associated with the lung parenchyma 26. The intercostal neurovascular bundle is particularly vulnerable to injury from fractured ribs because it is located A above the superior border of the ribs, anteriorly B beneath the inferior border of the ribs, posterolaterally C between external and internal intercostal muscle layers D deep to the posterior intercostal membrane E superficial to the ribs, anteriorly 27. The sinuatrial node in the heart receives its blood supply principally from A the anterior interventricular branch of the left coronary artery B the circumflex branch of the left coronary artery C the posterior interventricular branch of the right coronary artery D the right coronary artery E none of the above 28. All the following statements concerning the annulus fibrosus are correct EXCEPT A it completely separates the atrial musculature from that of the ventricles B it permits passage of the atrio-ventricular bundle C it provides the point of attachment for the cardiac muscle D it separates the sinuatrial node from the atrioventricular node E it supports the valves of the heart Questions 29-32 A 38-year-old man is seen in the emergency room complaining of severe chest pain. He tends to sit leaning forward. Upon physical examination he is noted to be tachypneic (breathing rapidly); he has a rapid pulse rate, and on auscultation of the chest his valve sounds appear “distant.” A radiograph shows a globular heart shadow. All evidence indicates pericarditis with pericardial effusion. 29. The pain originating in the parietal pericardium travels by way of A the cardiac plexus B greater splanchnic nerves C intercostal nerves D vagus nerves E none of the above 30. The heart sound associated with closure of the aortic valve is heard most distinctly A immediately to the left of the sternal angle B immediately to the right of the sternal angle C just inferior to the left nipple D just inferior to the right nipple E over the xiphoid process 31. Pericardiocentesis (to drain the exudate) via the costoxiphoid approach passes through which of the following structures? A The interchondral portion of an internal oblique muscle B The left pleura C The rectus sheath and rectus abdominis muscle D The visceral pericardium E None of the above 32. Vessels at high risk during the costoxiphoid approach include A the anterior interventricular artery B the left internal thoracic artery C the right coronary artery D the right marginal artery E none of the above Questions 33-35 A 36-year-old male office worker comes to the clinic complaining of general weakness and shortness of breath. He also relates a rapid, throbbing pulse after climbing a flight of stairs. 33. Cardiac auscultation reveals a diastolic rumbling murmur attributable to the mitral valve. The mitral valve is best heard on the A left side adjacent to the sternum in the second intercostal space B left side adjacent to the sternum in the fifth intercostal space C left side in the midclavicular line in the fifth intercostal space D right side adjacent to the sternum in the second intercostal space E right side adjacent to the sternum in the fourth intercostal space 34. A posteroanterior chest x-ray indicated moderate enlargement of the heart. Normally, the shadow of the heart on a posteroanterior radiograph : should not exceed what fraction of the chest diameter? A One-quarter B One-third C One-half D Two-thirds 35. A complication of mitral stenosis is the formation of thrombi in the enlarged left atrium. A thrombus dislodged from the left atrial wall may produce all the following EXCEPT A gangrene of the leg by occluding a branch of the femoral artery B myocardial infarct by occluding a coronary artery C pulmonary embolus by occluding a pulmonary artery D renal infarct by occluding a segmental renal artery E stroke by occluding a cerebral artery Questions 36-45 A 64 year old man is brought into the emergency room after experiencing more than 3 h of increasing chest pain that was unrelieved by rest antacids, or nitroglycerin. He complains of nausea without vomiting. Further (questioning reveals a 2-year history of exertional angina pectoris (pressing chest pain that often radiated along the inner aspect of the left arm when the patient climbed one flight of stairs). Propranolol, which reduces the response of the heart to stress, and nitroglycerm, which dilates systemic veins as well as coronary arteries had been prescribed previously. On physical examination he is found to be acyanotic (normal blood oxygenation), tachypneic (rapid breathing), tachycardiac (rapid pulse rate) with a regular rhythm and diaphoretic (sweating). 36. This patient’s tachycardia probably is mediated by reflex arcs associated with decreased cardiac output and possibly reduced blood pressure. The visceral efferent (motor) pathway of this cardiac response is mediated by the A carotid branches of the glossopharyngeal nerves B greater splanchnic nerves C phrenic nerves D sympathetic cervical and thoracic cardiac fibers E vagus and recurrent laryngeal nerves 37. The superficial and deep cardiac plexuses, located in the middle mediastinum, receive contributions from all the following EXCEPT the A cervical sympathetic ganglia B phrenic nerves C recurrent laryngeal nerves D upper thoracic sympathetic ganglia E vagus nerves 38. In angina pectoris, the pain radiating down the left arm is mediated by increased activity in afferent (sensory) fibers contained in A the carotid branch of the glossopharyngeal nerves B the greater splanchnic nerves C the phrenic nerves D the vagus nerve and recurrent laryngeal nerves E none of the above 39. Angina pectoris, which can be explained on the basis of anatomic path ways, is an example of A imagined pain B psychomotor neurosis C referred pain D somatic pain E none of the above 40. The patient is admitted to a coronary care unit for tests and observation. An electrocardiogram reveals a pattern consistent with a small ventricular posteroseptal infarct from ischemic necrosis that resulted from inadequate blood supply. Despite the rapid heart beat, its regularity indicates that the infarct has involved only A a localized region of ventricular myocardium B both atrioventricular node and bundle C the atrioventncular bundle D the atrioventricular node E the sinuatrial node 41. In the diagram of a normal heart shown below, the coronary artery most likely to be involved in a posteroseptal infarct (as in this patient) is indicated by which letter? AA BB CC DD EE 42. The “margin of safety” provided for the coronary circulation is less than for other parts of the body for which of the following reasons? A Blood flows through the coronary circulation only during diastole (cardiac relaxation) B The coronary arteries arise from the truncus arteriosus just before the semilunar valves C The leaflets of the semilunar valves impede the flow of blood into the coronary circulation D The right coronary artery normally arises from the pulmonary trunk, whereas the left normally arises from the aorta E None of the above 43. The patient recovers and is discharged from the hospital. Even with rest and increased doses of propranolol, however, his angina pectoris persists and, in fact, the attacks progress to angina decubitis (angina at rest). On his readmission to the hospital, coronary angiography is ordered. From this angiogram, the coronary circulation may best be described as A balanced B left preponderant C right dominant D right preponderant E impossible to determine 44. The coronary angiogram (see previous question) indicates that the right coronary artery is free of pathology. The left coronary artery is found to be 70 to 80 percent occluded at three points proximal to its bifurcation into the circumflex and anterior interventricular arteries. Without surgery and with the coronary distribution pattern shown previously, the prognosis for recovery of this patient to a normally active life is considerably reduced because A all branches of the coronary arteries are end-arteries, precluding the chance that anastomotic connections will occur B the anterior and posterior papillary muscles of the tricuspid valve may be damaged C the blood supply to the sinuatrial node is inadequate D the development of effective collateral circulation between anterior and posterior interventricular arteries is not possible in this case E of none of the above 45. To improve the blood flow to the interventricular septum, a coronary by-pass procedure is elected. A section of superficial vein, removed from the lower portion of the patient’s leg, is grafted from the aorta to the coronary artery just distal to the site of occlusion. In coronary bypass surgery, which of the following statements is true? A The proximal end of the vein is anastomosed to the aorta B The distal end of the vein is anastomosed to the aorta C The orientation is unimportant because aortic pressure is always higher than venous pressure D The orientation is unimportant because the vein is being used as an artery E The orientation would be important only if a coronary vein were being bypassed 46. The first (S1, or “Lub”) heart sound and the second (S2, or “Dup”) heart sound originate, respectively, from the A closure of the pulmonary valve followed by closure of the aortic valve B closure of the tricuspid valve followed by closure of the mitral valve C closure of the atrioventricular valves followed by closure of the semilunar valves D closure of the atrioventricular valves followed by opening of the semilunar valves E opening of the atrioventricular valves followed by closure of the atrioventricular valves 47. A substance abuser (heroin mainliner) is diagnosed as having tricuspid insufficiency as a result of bacterial endocarditis (infection of the endocardium and valves). The examining physician might expect to note all the following signs EXCEPT A abdominal ascites B distended neck veins C pulmonary edema D swelling of the ankles E systolic murmur, most distinct in the right fifth interchondral space 48. Which of the following statements correctly pertains to the papillary muscles in the heart? A They are rudimentary and have no major function B They contract to close the atrioventricular valves C They contract to open the atrioventricular valves D They secure the chordae tendineae to the atrioventricular valve leaflets E None of the above 49. Circulatory changes that occur immediately at birth normally include all the following EXCEPT A closure of the ductus arteriosus B decreased right atrial pressure C increased blood flow through the lungs D increased left atrial pressure E momentary reversal of flow through the foramen ovale 50. Structures that normally transit the diaphragm by way of the esophageal hiatus include the A aorta B azygos vein C hemiazygos vein D posterior vagal trunk E thoracic duct 51. Blood is returned to the left side of the heart by A the anterior cardiac veins B the coronary sinus C the ductus arteriosus D the pulmonary arteries E none of the above DIRECTIONS: The group of questions below consists of four lettered headings followed by a set of numbered items. For each numbered item select A if the item is associated with (A) only B if the item is associated with (B) only C if the item is associated with both (A) and (B) D if the item is associated with neither (A) nor (B) Each lettered heading may be used once, more than once, or not at all. Questions 52-56 A Gray ramus communicans B White ramus communicans C Both D Neither 52. Parasympathetic neurons 53. General visceral afferent neurons 54. Unmyelinated neurons 55. Every spinal nerve 56. Neurons that terminate on sweat glands and smooth muscle DIRECTIONS: The group of questions below consists of lettered headings followed by a set of numbered items. For each numbered item select the one lettered heading with which it is most closely associated. Each lettered heading may be used once, more than once, or not at all. Questions 57-60 Movements of the chest wall and diaphragm produce changes in thoracic volume and pulmonary ventilation. For each respiratory muscle action described below, select the factor to which it is most nearly related. A A factor in quiet inspiration B A factor in quiet expiration C An accessory factor in exertional inspiration D A factor in exertional expiration E Not a factor in respiration 57. Contraction of the interchondral (parasternal) portion of the internal intercostal muscles 58. Contraction of the rectus abdominis muscle 59. Contraction of the sternocleidomastoid muscle 60. Contraction of the internal oblique muscle Literature 1. Snell R.S. Clinical Anatomy for medical students. – Lippincott Williams & Wilkins, 2000. – 898 p. 2. Skandalakis J.E., Skandalakis P.N., Skandalakis L.J. Surgical Anatomy and Technique. – Springer, 1995. – 674 p. 3. Netter F.H. Atlas of human anatomy. – Ciba-Geigy Co., 1994. – 514 p. 4. Ellis H. Clinical Anatomy Arevision and applied anatomy for clinical students. – Blackwell publishing, 2006. – 439 p.