AN21.1-11 | Thoracic cage — Glossary

A flat bone in the centre of the anterior chest wall with three parts: manubrium, body, and xiphoid process

The angle of Louis at the manubriosternal junction, marking the 2nd costal cartilage, tracheal bifurcation, aortic arch, and T4/T5 level

The suprasternal notch at the top of the manubrium, palpable between the clavicles, at the level of T2

The small pointed inferior part of the sternum, a danger zone during CPR as fracture can lacerate the liver

A groove on the inferior internal surface of the rib shaft that shelters the intercostal neurovascular bundle (VAN)

The vein, artery, and nerve (VAN order from top) running in the costal groove between internal and innermost intercostal muscles

The outermost intercostal muscle with fibres running downward and forward, active during inspiration

The middle intercostal muscle with fibres running downward and backward, active during forced expiration

Rib elevation increasing the anteroposterior diameter by moving the sternum forward, occurring mainly in upper ribs

Rib elevation increasing the transverse diameter by swinging the lateral shaft outward, occurring mainly in lower ribs

The lateral cutaneous branch of T2 crossing the axilla to supply medial arm skin, explaining referred cardiac pain to the inner arm

A synovial joint where the rib head articulates with vertebral body demifacets and the intervertebral disc

A synovial joint where the rib tubercle articulates with the costal facet on the transverse process

The superior thoracic aperture bounded by T1, first ribs, and manubrium through which structures pass between neck and thorax

The inferior thoracic aperture closed by the diaphragm, bounded by T12, lower ribs, and xiphoid process

The central compartment of the thorax between the two pleural cavities, divided into superior and inferior (anterior, middle, posterior)

A prominence on the 1st rib for scalenus anterior attachment, separating the grooves for subclavian vein (anterior) and artery (posterior)

An extra rib from C7, present in 0.5% of people, can compress the subclavian artery or lower trunk of brachial plexus

A primary cartilaginous joint where bony rib meets costal cartilage with no movement and no joint cavity

A branch of the subclavian artery running behind the costal cartilages, supplying anterior intercostal arteries to spaces 1-6

Performed in the 5th intercostal space mid-axillary line, over the upper border of the rib below to avoid the neurovascular bundle

Three or more adjacent ribs fractured in two places each, creating a segment that moves paradoxically during breathing

Surgical splitting of the sternum for cardiac bypass surgery, the most common approach to the heart