The chest, also called the thorax, extends from the neck to the
lower reaches of the ribs. The bones of the chest surround a space
called the thoracic cavity. The thoracic cavity is divided into
the mediastinum and the pleural cavities.
The Thoracic Cavity
The mediastinum is the area that lies in the center of the thoracic
cavity with the diaphragm at its base. It contains the trachea,
esophagus, heart, aorta, vena cava and the pulmonary artery. The
lungs are not part of the mediastinum.
The pleural cavities lie on each side of the mediastinum. Each pleural
cavity contains one lung.
A thin double-walled tissue lines both pleural
cavities. The visceral pleura lines the outside of
the lungs. The parietal pleura lines the inside of
the thoracic cavity. There is a potential space between
the visceral and parietal pleura. A thin layer of fluid
provides lubrication during chest wall expansion
and contraction.
