LWBK529-C09_076-087.qxd 3/9/10 1:17 PM Page 81 Aptara
Thorax I: Anterior Thoracic Wall
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Superior interpleural area (thymic region) Cupula (cervical pleura) Apex, left lung
Upper lobe, right lung
Upper lobe, left lung Cardiac notch
Sternal angle Horizontal fissure
Oblique fissure Middle lobe, right lung
Inferior interpleural area (cardiac region)
Oblique fissure Lower lobe, right lung
Lower lobe, left lung Lingula, left lung
FIGURE 9-6 Projection of the pleural cavity and lungs onto the anterior surface of the rib cage. The pleural cavity is shown in red. The lungs extend to ribs 6, 8, and 10, whereas the pleura extends to ribs 8, 10, and 12 in the midclavicular, midaxillary, and posterior lines.
(5) On the left side, draw the pleura comparably to the right. From the cupula anteriorly descend to approximately the 4th rib where the pleura curves laterally away from the midline to form a notch of 2 inches in diameter for the pericardium. (6) Continue the line along the costal margin around to the posterior chest at the same levels as on the right side (ATLAS PLATES 154–156). b. Projection of the lungs (Figure 9-6). (1) As with the pleura, commence in the neck 2.5 cm above the clavicle and 4 cm lateral to the sternoclavicular joints where the apex of each lung occupies the cupula of the pleural sac (ATLAS PLATE 154 #154.1). (2) From this site draw the anterior borders of the two lungs just lateral to the midsternal lines taken by the pleura.
Grant’s 30, 31 Netter’s 196, 197 Rohen 247, 248
(3) On the right side, draw the anterior border downward to the xiphisternal junction. (4) On the left side, draw a notch in the anterior margin of the left lung at the level of the 4th rib that deviates 5 cm (2 inches) to the left (Figure 9-6). (5) Draw the inferior borders of the lungs two ribs above the lines of the parietal pleura: the 6th rib at the midclavicular line, the 8th rib in the midaxillary line, and the 10th rib in the midportion of the back (ATLAS PLATES 154–156). The notch on the left side accommodates the heart and pericardium where it lies directly under the thoracic wall uncovered by lung tissue. Upon percussion here, a dull sound results rather than the resonant tone found over lung tissue containing air, and therefore, is called the area of superficial cardiac dullness (ATLAS PLATES 152, 168, 169).