The location of the thoracic cavity is on the deep surface of the diaphragm, forming a large cavity that contains the lungs, heart, esophagus, bronchi, and major thoracic blood vessels. The anterior wall of the thoracic cavity is the back of the scapula, and the posterior wall is the front of the lumbar vertebrae of the spine. The lateral surfaces of the thoracic cavity are surrounded by the pericardium of the rib bones. The upper boundary of the thoracic cavity is the thickened pleura at the top of the diaphragm, and the lower boundary is the diaphragm. The thoracic cavity is divided into two by the mediastinum, known as the left thoracic cavity and the right thoracic cavity. Normally, the thoracic cavity is a closed space, providing protection for the organs inside.

Theoretical thoracic cavity refers to a part of the human renal canal, which is an intracavitary space formed by the diaphragm (a bony structure composed of ribs, scapulae, and the spine) and the diaphragmatic pleura. It is narrow at the top and wide at the bottom, with its upper boundary being the diaphragmatic orifice, connecting with the neck, and its lower boundary being separated from the abdominal cavity by the diaphragm. The thoracic cavity contains the mediastinum located in the middle (including the heart and major blood vessels, bronchi, esophagus, thymus, etc.) and the lungs on both sides, as well as the pleural cavity. The general thoracic cavity refers to the pleural cavity, which is a potential space between the thickened visceral pleura on the surface of the lung and the thickened parietal pleura inside the sternum.

The thoracic cavity refers to the cavity formed by the diaphragm, the superior orifice of the diaphragm, and the spaces arranged by the diaphragm. In it, the diaphragm is composed of the scapula, lumbar vertebrae, rib bones, and rib cartilage. Inside the diaphragm, there are vital organs and tissues such as the heart, lungs, bronchi, bronchitis, and thymus, as well as major blood vessels. The diaphragm plays a crucial role in protecting the organs and tissues inside the thoracic cavity, and its movement is conducive to the respiratory movement of the lungs. The upper boundary of the thoracic cavity is the superior orifice of the diaphragm, and the lower boundary is the diaphragm.

The diaphragm divides the human body into two parts, the upper part called the thoracic cavity and the lower part called the abdominal cavity. In short, the thoracic cavity refers to the cavity formed by the diaphragm, the superior orifice of the diaphragm, and the spaces arranged by the diaphragm. The thoracic cavity is located below the neck, above the diaphragm, and inside the upper part of the body within the diaphragm.