Rib 1

Rib 1 or the first rib is the most superior and shortest of the twelve pairs of ribs in the human body. It is a true rib, and like other true ribs, it connects to the sternum via the costal cartilage.

Anatomy

The first rib is unique in its shape and size compared to the other ribs. It is broad and flat, curved in a horizontal C-shape, and significantly shorter than the rest of the ribs. It has a single articulation (joint) with the thoracic vertebrae at the T1 vertebra.

The first rib has two surfaces, an upper (superior) and a lower (inferior), and two borders, a front (anterior) and a back (posterior). The superior surface features a groove for the subclavian artery and subclavian vein, which supply blood to and from the upper limb. The inferior surface is smooth and concave, and is in contact with the pleura of the lung.

Clinical significance

Due to its close proximity to vital structures such as the subclavian artery, subclavian vein, and brachial plexus, the first rib can be involved in several medical conditions. One such condition is thoracic outlet syndrome, where compression of these structures can lead to pain, numbness, and weakness in the upper limb.

See also

• Rib cage
• Thoracic vertebrae
• Costal cartilage