This is the prominent projection at the base of the neck on the external surface of the rib. It can be divided into a smooth articular portion and a rough nonarticular part. The smooth articular facet forms a synovial joint with the transverse process of the corresponding thoracic vertebra. The nonarticular aspect of the tubercle provides attachment to costotransverse ligaments.

Tubercle comes from the Latin tuber for a lump, combined with the diminutive ending denoting a small lump.

Tuberculum

Tubercule

Tuberkel

Tubérculo