sternal line of pleural reflection
Introduction
Surface projection of the sharp or abrupt line, where the costal pleura becomes continuous with the mediastinal pleura anteriorly.
The right & left sternal lines are:
- parallel to the to the median plane, posterior to the sternum at the level of costal cartilages 2-4
The sternal line on the right side passes inferiorly in the median plane to the posterior aspect of the xiphoid process, where it turns laterally.
The sternal line on the left side passes inferiorly in the median plane to the level of the 4th costal cartilage. At the level of the costal cartilage 4, the left line turns laterally to parallel the left margin of the sternum. This in turn creates a notch, shallower than the cardiac notch of left lung & an area where the pericardial sac contacts the anterior thoracic wall without intervening pleura sac - significant for pericardiocentesis.