Head Of The First Rib, Superior View

Description

First rib head occupies the posterior, medial end of the rib and, in superior view, its wedge-shaped articular surface faces medially toward the body of the first thoracic vertebra (T1). The single costal facet is oriented to meet the T1 vertebral body and adjacent intervertebral disc, while the neck extends laterally from the head toward the tubercle and shaft. Posterior to the neck, the region where the costotransverse articulation occurs with the transverse process of T1 lies just lateral to the head, defining the transition from the rounded vertebral end to the flatter superior surface of the rib. Orientation is everything. This perspective matters when you need to teach or document the first costovertebral joint, where joint congruency and ligament attachments, including the radiate ligament of the head of the rib and the costotransverse ligaments across the neck and tubercle, stabilize the thoracic cage during respiration. Clinically, the first rib is a key landmark in thoracic outlet syndrome and in trauma, but proximal fixation at T1 also influences how fractures and osteophytes can irritate adjacent structures, including the T1 spinal nerve near the intervertebral foramen. The superior lighting and isolation of the articular surface make facet shape and orientation easy to compare with the typical ribs (2 to 9), which more often carry demifacets rather than a single facet. Use this illustration in gross anatomy and osteology teaching to differentiate rib 1 from other thoracic ribs, and in spine or thoracic surgery publications when labeling the costovertebral and costotransverse joints at the cervicothoracic junction. It also fits radiology teaching files that correlate bony landmarks with CT assessment of the thoracic inlet and upper thorax. Anatomical accuracy verified by SciePro's Medical Advisory Board.