The thoracic cavity is organized into three major compartments—the right and left pleural cavities (each housing a lung) and the mediastinum between them—with the mediastinum further subdivided by anatomic boundaries (sternal angle to T4/T5 plane separating superior from inferior; the inferior mediastinum further divided into anterior, middle, and posterior regions relative to the pericardium) that determine which viscera occupy each division. This compartmental framework in human anatomy links structural topography (lung apex/base limits, mediastinal boundaries) to functional and clinical correlates, such as the surface locations for cardiac valve auscultation and the immunologic role of the thymus in T-lymphocyte self-antigen education.
The thoracic cavity is organized into three major compartments—the right and left pleural cavities (each housing a lung) and the mediastinum between them—with the mediastinum further subdivided by an…