Thoracic inlet

Thoracic inlet, also known as the superior thoracic aperture, refers to the upper opening of the thoracic cavity. It is bordered by the manubrium of the sternum, the first pair of ribs and their costal cartilages, and the first thoracic vertebra (T1). The thoracic inlet serves as a pathway for structures that move between the neck and the thorax.

Anatomy[edit | edit source]

The thoracic inlet is an oval-shaped opening with its long axis running from front to back. It measures approximately 5 cm in width and 4 cm in depth. The anterior border is formed by the manubrium of the sternum, the lateral borders by the first pair of ribs and their costal cartilages, and the posterior border by the first thoracic vertebra.

Structures passing through[edit | edit source]

Several important structures pass through the thoracic inlet, including the trachea, esophagus, and major blood vessels such as the common carotid arteries, subclavian arteries, and internal jugular veins. The vagus nerve, phrenic nerve, and sympathetic trunk also pass through this opening.

Clinical significance[edit | edit source]

Due to its location and the vital structures that pass through it, the thoracic inlet can be involved in several medical conditions. For example, thoracic outlet syndrome (TOS) is a group of disorders that occur when the blood vessels or nerves in the space between the collarbone and the first rib (thoracic outlet) become compressed. This can cause pain in the shoulders and neck and numbness in the fingers.