U of M Thorax Flashcards
1. The second costal cartilage can be located by palpating the: A. costal margin B. sternal angle C. sternal notch D. sternoclavicular joint E. xiphoid process
The correct answer is: B. sternal angle
The sternal angle is the point where the costal cartilage attaches the second rib to the sternum. This is an important anatomical landmark to remember–it is used to find the valves when auscultating the heart! The costal margins are formed by the medial borders of the 7th through 10th costal cartilages. They are easily palpable and extend inferolaterally from the xiphisternal joint. The sternal notch/jugular notch is the notch located at the superior border of the manubrium, between the sternal ends of the clavicles. The sternoclavicular joints are simply the joints connecting the sternum with the clavicles. Finally, the xiphoid process is the bone that makes the inferior part of the sternum.
2. The thoracic wall is innervated by: A. Dorsal primary rami B. Intercostal nerves C. Lateral pectoral nerves D. Medial pectoral nerves E. Thoracodorsal nerves
The correct answer is: B. intercostal nerves
Intercostal nerves are the ventral primary rami of spinal nerves T1-T11. They provide motor innervation to intercostal muscles, abdominal wall muscles (via T7-T11) and muscles of the forearm and hand (via T1). They provide sensory innervation to the skin of the chest and abdomen on the anterior and lateral sides. The other nerves listed do not innervate the chest wall. Dorsal primary rami provide motor innervation to true back muscles and sensory innervation to the skin on the back. The lateral pectoral nerve provides motor innervation to pectoralis major only, while the medial pectoral nerve provides motor innervation to pectoralis major and minor. The thoracodorsal nerve provides motor innervation to latissimus dorsi.
3. The sternocostal surface of the heart is formed primarily by the anterior wall of which heart chamber? A. Left atrium B. Left ventricle C. Right atrium D. Right ventricle
The correct answer is: D. right ventricle
The heart has three important surfaces: an anterior surface, a diaphragmatic surface, and a pulmonary surface. The anterior surface, or sternocostal surface, is mostly made up of the right ventricle. The diaphragmatic surface is mostly the left ventricle, but a little bit of the right ventricle sits on the diaphragm as well. Finally, the pulmonary surface, which is on the left, is mostly made up of the left ventricle.
4. A patient involved in an automobile accident presents with a sharp object puncture of the middle of the sternum at about the level of the 4th or 5th costal cartilage. If the object also penetrated pericardium and heart wall, which heart chamber would most likely be damaged? A. Left atrium B. Left ventricle C. Right atrium D. Right ventricle
The correct answer is: D. right ventricle
Remember, the anterior surface, or sternocostal surface, of the heart is mostly made up of the right ventricle. So, if an object punctured the sternum, it would be likely to pierce the right ventricle.
5. You are caring for a 68-year-old male who has copious amounts of fluid in the left pleural cavity due to acute pleurisy. When you examine him as he sits up in bed (trunk upright), where would the fluid tend to accumulate? A. costodiaphragmatic recess B. costomediastinal recess C. cupola D. hilar reflection E. middle mediastinum
The correct answer is: A. costodiaphragmatic recess
The costodiaphragmatic recess is the lowest extent of the pleural cavity or sac. It is the part of the pleural sac where the costal pleura changes into the diaphragmatic pleura. Because this is the most inferior part of the pleural sac, fluid in the pleural sac will fall to this region when a patient sits up. The costodiaphragmatic recess is also the area into which a needle is inserted for thoracocentesis, and it is found at different levels at different areas of the thorax. At the mid-clavicular line, the costodiaphragmatic recess is between ribs 6 and 8; at the midaxillary line it is between 8 and 10; and at the paravertebral line it is between 10 and 12.
The costomediastinal recess is found where the costal pleura becomes the mediastinal pleura. The cupola is the part of the pleural cavity which extends above the level of the 1st rib into the root of the neck. The hilar reflection is the point at the root of the lung where the mediastinal pleura is reflected and becomes continuous with the visceral pleura. Finally, the middle mediastinum is the space in the mediastinum which contains the heart, pericardium, great vessels, and bronchi (at the roots of the lung).
6. A 23-year-old male injured in an industrial explosion was found to have multiple small metal fragments in his thoracic cavity. Since the pericardium was torn inferiorly, the surgeon began to explore for fragments in the pericardial sac. Slipping her hand under the heart apex, she slid her fingers upward and to the right within the sac until they were stopped by the cul-de-sac formed by the pericardial reflection near the base of the heart. Her fingertips were then in the: A. coronary sinus B. coronary sulcus C. costomediastinal recess D. oblique sinus E. transverse sinus
The correct answer is: D. oblique sinus
The oblique sinus is an area of the pericardial cavity located behind the left atrium of the heart where the serous pericardium reflects onto the inferior vena cava and pulmonary veins. If you slide your fingers under the heart, they will be in the oblique sinus. The other pericardial sinus that you should be familiar with is the transverse sinus. The transverse sinus is an area of the pericardial cavity located behind the aorta and pulmonary trunk and anterior to the superior vena cava. It separates the outflow vessels from inflow vessels.
The coronary sinus is a large vein on the heart which drains into the right atrium. The coronary sulcus is a groove on the heart which separates the atria from the ventricles. The costomediastinal recess is an area in the pleural sac where the costal pleura changes to the mediastinal pleura.
- When inserting a chest tube, intercostal vessels and nerves are avoided by placing the tube immediately:
A. above the margin of a rib
B. below the margin of a rib
The correct answer is: A. above the margin of a rib
The VAN triad of an intercostal vein, artery, and nerve run along the bottom of a rib, in the costal groove. To avoid hitting any of these important structures, it is important to remember to always place a tube or needle above the margin of a rib (or,if you prefer to think about it this way, at the bottom of an intercostal space).
8. A hand slipped behind the heart at its apex can be extended upwards until stopped by a line of pericardial reflection that forms the: A. Cardiac notch B. Costomediastinal recess C. Hilar reflection D. Oblique pericardial sinus E. Transverse pericardial sinus
The correct answer is: D. oblique pericardial sinus
The oblique pericardial sinus is an area of the pericardial cavity located behind the left atrium of heart where the serous pericardium reflects onto the inferior vena cava and pulmonary veins. If you slide your fingers under the heart, they will be in this space. The other pericardial sinus that you should be familiar with is the transverse sinus. The transverse sinus is an area of the pericardial cavity located behind the aorta and pulmonary trunk and anterior to the superior vena cava. It separates the outflow vessels from inflow vessels.
The cardiac notch is an indentation in the superior lobe of the left lung which creates the lingula. The costomediastinal recess is an area in the pleural sac where the costal pleura changes to the mediastinal pleura. Finally, the hilar reflection is the reflection of pleura on the root of the lung, where visceral pleura on the lung becomes continuous with the mediastinal pleura.
9. The first rib articulates with the sternum in close proximity to the: A. Nipple B. Root of the lung C. Sternal angle D. Sternoclavicular joint E. Xiphoid process
The correct answer is: D. sternoclavicular joint
The first rib articulates with the sternum directly below the sternoclavicular joint. The nipple is found in the fourth intercostal space, between the 4th and 5th ribs. The sternal angle is connected to the costal cartilage of rib 2. Finally, the xiphoid process is located just below the point where the costal cartilage of rib 7 articulates with the sternum. The root of the lung consists of the main bronchus, pulmonary and bronchial vessels, lymphatic vessels, and nerves entering and leaving the lung.
10. The portion of the parietal pleura that extends above the first rib is called the : A. costodiaphragmatic recess B. costomediastinal recess C. costocervical recess D. cupola E. endothoracic fascia
The correct answer is: D. cupola
The cupola is the cervical parietal pleura which extends slightly above the level of the 1st rib into the root of the neck. The costodiaphragmatic recess is the part of the pleural sac where the costal pleura changes into the diaphragmatic pleura. It is the lowest extent of the pleural sac. The costomediastinal recess is found where the costal pleura becomes the mediastinal pleura. Endothoracic fascia is connective tissue between the inner chest wall and costal parietal pleura. The costocervical recess is a made up term.
11. You are attending an operation to remove a thymic tumor from the superior mediastinum. The surgeon asks, "What important nerve lying on and partly curving posteriorly around the arch of the aorta should we be careful of as we remove this mass?" You quickly answer, "The-- A. left phrenic B. left sympathetic trunk C. left vagus D. right phrenic E. right sympathetic trunk
The correct answer is: C. left vagus
The left vagus nerve lies against the lateral surface of the arch of the aorta. The left recurrent laryngeal nerve is an especially important nerve from the vagus which loops around the aortic arch. This nerve innervates the muscles of the left larynx. If it is damaged, a patient may experience hoarseness after surgery. Care must be taken to preserve this nerve, especially during thyroid surgery.
The left and right phrenic nerves, which innervate the diaphragm, are lateral to the vagus nerves and are not looping near the aortic arch. The left and right sympathetic trunks lie on the posterior chest wall and are not involved with the aortic arch.
12. In cardiac surgery it is sometimes necessary to clamp off all arterial flow out of the heart. This could be done within the pericardial sac by inserting the index finger immediately behind the two great arteries and compressing them with the thumb of the same hand. The index finger would have to be inserted into which space? A. Cardiac notch B. Coronary sinus C. Oblique pericardial sinus D. Coronary sulcus E. Transverse pericardial sinus
The correct answer is: E. Transverse pericardial sinus
The transverse pericardial sinus is an area of the pericardial cavity located behind the aorta and pulmonary trunk and anterior to the superior vena cava. When entering the transverse pericardial sinus, a surgeon will insert an index finger between the aorta and pulmonary trunk on the ventral side and the superior vena cava on the dorsal side. The oblique pericardial sinus is an area of the pericardial cavity located behind the left atrium of the heart. If a surgeon places fingers under the apex of the heart, then moves the fingers until they are stopped by a pericardial reflection, then the fingers are in the oblique sinus. You should understand what these two sinuses are and how they can be entered!
The cardiac notch is a structure on the left lung which separates the lingula below from the upper portion of the superior lobe of left lung. The coronary sinus is a venous sinus on the posterior surface of the heart which receives blood from the smaller veins which drain the heart. The coronary sulcus is a groove on the heart, between the atria and ventricles. The coronary sinus, circumflex artery, and right coronary artery lie in the coronary sulcus.
13. A needle inserted into the 9th intercostal space along the midaxillary line would enter which space? A. Cardiac notch B. Costodiaphragmatic recess C. Costomediastinal recess D. Cupola E. Oblique pericardial sinus
The correct answer is: B. Costodiaphragmatic recess
The costodiaphragmatic recess is the lowest extent of the pleural cavity or sac. It is the part of the pleural sac where the costal pleura changes into the diaphragmatic pleura. It is also the area into which a needle is inserted for thoracocentesis, and it is found at different levels at different areas of the thorax. At the mid clavicular line, the costodiaphragmatic recess is between ribs 6 and 8; at the midaxillary line it is between 8 and 10; and at the paravertebral line it is between 10 and 12. So, inserting the needle just above the 9th rib at the midaxillary line should put you in the costodiaphragmatic recess.
The cardiac notch is a structure on the left lung which separates the lingula below from the upper portion of the superior lobe of left lung. The costomediastinal recess is found where the costal pleura becomes the mediastinal pleura. The cupola is the part of the pleural cavity which extends above the level of the 1st rib into the root of the neck. The oblique pericardial sinus is an area of the pericardial cavity located behind the left atrium of the heart.
- During a heart transplant procedure, the surgeon inserted his left index finger through the transverse pericardial sinus, and then pulled forward on the two large vessels lying ventral to his finger. Which vessels were these?
A. Pulmonary trunk and brachiocephalic trunk
B. Pulmonary trunk and aorta
C. Pulmonary trunk and superior vena cava
D. Superior vena cava and aorta
E. Superior vena cava and right pulmonary artery
The correct answer is: B. Pulmonary trunk and aorta
The transverse pericardial sinus is an area of the pericardial cavity located behind the aorta and pulmonary trunk and anterior to the superior vena cava. So, the two large vessels lying ventral to his finger are the pulmonary trunk and aorta; the large vessel lying dorsal to his finger is the superior vena cava.
15. While observing in the OR, you see the resident insert a needle through the body wall just above the ninth rib in the mid-axillary line. She was obviously trying to enter the: A. Costodiaphragmatic recess B. Costomediastinal recess C. Cupola D. Hilar reflection E. Pulmonary ligament
The correct answer is:A. Costodiaphragmatic recess
The costodiaphragmatic recess is the lowest extent of the pleural cavity or sac. It is the part of the pleural sac where the costal pleura changes into the diaphragmatic pleura. It is also the area into which a needle is inserted for thoracocentesis, and it is found at different levels at different areas of the thorax. At the mid clavicular line, the costodiaphragmatic recess is between ribs 6 and 8; at the midaxillary line it is between 8 and 10; and at the paravertebral line it is between 10 and 12. So, inserting the needle just above the 9th rib at the midaxillary line should put the resident’s needle in the costodiaphragmatic recess. Make sure you know where to enter the costodiaphragmatic recess at the midclavicular line, the mid axillary line, and the paravertebral line!
