Thoracic aperture

Thoracic aperture

The thoracic aperture refers to the openings at the top and bottom of the thoracic cavity, which allow for the passage of structures between the thorax and other regions of the body. There are two thoracic apertures: the superior thoracic aperture and the inferior thoracic aperture.

Superior Thoracic Aperture

The superior thoracic aperture, also known as the thoracic inlet, is the opening at the top of the thoracic cavity. It is bounded by:

• The first thoracic vertebra (T1 vertebra)
• The first pair of ribs and their costal cartilages
• The superior border of the manubrium of the sternum

This aperture allows for the passage of several important structures, including the trachea, esophagus, major blood vessels such as the brachiocephalic artery, left common carotid artery, and the left subclavian artery, as well as nerves like the vagus nerve and the phrenic nerve.

Inferior Thoracic Aperture

The inferior thoracic aperture, also known as the thoracic outlet, is the opening at the bottom of the thoracic cavity. It is bounded by:

• The twelfth thoracic vertebra (T12 vertebra)
• The twelfth pair of ribs and the costal margins formed by the cartilages of ribs 7-10
• The xiphisternal joint, where the xiphoid process meets the body of the sternum

The inferior thoracic aperture is closed off by the diaphragm, a major muscle involved in respiration. Structures passing through this aperture include the aorta, the inferior vena cava, and the esophagus.

Clinical Significance

The thoracic apertures are clinically significant as they are potential sites for various medical conditions. For instance, the superior thoracic aperture can be involved in thoracic outlet syndrome, a condition where nerves or blood vessels are compressed, leading to pain and other symptoms. The inferior thoracic aperture is important in procedures involving the diaphragm and in understanding the spread of diseases such as diaphragmatic hernia.

Related Pages

• Thoracic cavity
• Diaphragm (anatomy)
• Thoracic outlet syndrome
• Respiratory system
• Sternum
• Rib cage