Eighth rib

Costa spuria VIII

SkeletalSkeletonThoraxLeft and right

View left in 3D View right in 3D

What it is
The eighth rib, a false (vertebrochondral) rib: a curved flattened bar whose head articulates with T8 and the vertebra above, its tubercle with the T8 transverse process, sloping down and forward to its costal cartilage.
Function
Protects the thoracic organs and moves up and out with the intercostal muscles during breathing (bucket-handle motion).
Size
Cross-section ≈ 6 × 11 mm; arc length ≈ 27 cm
Clinical note
Rib fractures are most common at the angle of the rib, the weakest point of the curve.

Nearby skeletal structures Eighth costal cartilage, Eleventh rib, Fifth rib, Intervertebral disc T8–T9, Intervertebral disc T9–T10, Ninth costal cartilage, Ninth rib, Seventh rib, Sixth rib, Tenth rib