Second rib

Bones · Latin: Costa secunda

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The second rib is the second uppermost rib in humans or second most frontal in animals that walk on four limbs.

In humans, the second rib is defined as a true rib since it connects with the sternum through the intervention of the costal cartilage anteriorly (at the front).

Posteriorly, the second rib is connected with the vertebral column by the second thoracic vertebra.

The second rib is much longer than the first rib, but has a very similar curvature.

The non-articular portion of the tubercle is occasionally only feebly marked.

The angle is slight and situated close to the tubercle.

The body is not twisted so that both ends touch any plane surface upon which it may be laid; but there is a bend, with its convexity upward, similar to, though smaller than that found in the first rib.

The body is not flattened horizontally like that of the first rib.

Its external surface is convex, and looks upward and a little outward; near the middle of it is a rough eminence for the origin of the lower part of the first and the whole of the second digitation of the serratus anterior; behind and above this is attached the posterior scalene.

The internal surface, smooth, and concave, is directed downward and a little inward: on its posterior part there is a short costal groove between the ridge of the internal surface of the rib and the inferior border.

It protects the intercostal space containing the intercostal veins, intercostal arteries, and intercostal nerves.