Fig. 7.

The parietal pleura ( black arrows ) reflects at the level of the 10th rib in the midaxillary line, and variably along the 12th rib posteriorly. The lateral half of the 12th rib lies below the parietal pleura as it courses superiorly. The diaphragm ( black arrowheads ) usually inserts more inferiorly, along the lower margin of the 12th rib, the transverse process of the first lumbar vertebral body, and the anterior surface of the upper lumbar vertebral bodies. During quiet respiration, the lung normally does not fill the costophrenic sulcus, lying approximately at the 10th thoracic vertebral body posteriorly ( white arrowheads ), but can descend two vertebral levels with deep inspiration. Access above the lateral half of the 12th rib ( asterisk ) during expiration minimizes the risk of thoracic injury.