Thoracic cavity

The thoracic cavity (or chest cavity) is the chamber of the human body (and other animal bodies) that is protected by the thoracic wall (thoracic cage and associated skin, muscle, and fascia).

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Components

Structures within the thoracic cavity include:

• structures of the cardiovascular system, including the heart and great vessels, which include the thoracic aorta, the pulmonary artery and its branches, the superior and inferior vena cava, the pulmonary veins, and the azygos vein
• structures of the respiratory system, including the trachea, bronchi and lungs
• structures of the digestive system, including the esophagus,
• endocrine glands, including the thymus gland,
• structures of the nervous system including the paired vagus nerves, and the paired sympathetic chains,
• lymphatics including the thoracic duct.

It contains three potential spaces lined with mesothelium: the paired pleural cavities and the pericardial cavity. The mediastinum comprises those organs which lie in the centre of the chest between the lungs.

Boundaries

The thoracic cavity is separated from the abdominal cavity by the diaphragm. The thoracic inlet is the upper limit of the thoracic cavity, formed by the manubrium in front, the first ribs laterally, and the spine posteriorly.

Clinical significance

If the pleural cavity is breached from the outside, as by a bullet wound or knife wound, a pneumothorax, or air in the cavity, may result. If the volume of air is significant, one or both lungs may collapse, which requires immediate medical attention.

anterior abdominal wall (Arcuate line, Linea alba, Tendinous intersection, Linea semilunaris, McBurney's point, Traube's space, Inguinal triangle) • Inguinal canal (Deep inguinal ring, Superficial inguinal ring, Intercrural fibers, Crura of superficial inguinal ring) • Lumbar triangle • regions (Epigastrium, Hypochondrium, Umbilical region, Latus, Hypogastrium, Inguinal region) • planes (Transpyloric plane, Intertubercular plane, Midclavicular line)

Urogenital triangle (Superficial perineal pouch, Deep perineal pouch)

Perineal body