Quick Facts
Location: Thoracic cage.
Bone Type: Flat bone.
Key Features: Head, neck, tubercle, body, angle, and costal groove.
Articulates With: Fourth and fifth thoracic vertebrae, fifth costal cartilage.
Arterial Supply: Anterior intercostal branches of internal thoracic and posterior intercostal arteries.
Related parts of the anatomy
Key Features & Anatomical Relations
The fifth rib is one of the seven true ribs of the thoracic cage. It is considered a typical rib because it consists of a head with two articular facets, a neck, a tubercle, and a body.
The fifth rib is classified as a flat bone and includes the following bony features:
- parts: head, neck, tubercle, body, and costal end;
- surfaces: internal and external surfaces, and superior and inferior borders;
- landmarks: angle, costal groove, crests on the head and neck, and articular facets on the head and tubercle.
More information regarding these and other bony features can be found in the Parts, Surfaces, and Landmarks tabs for this bone.
The fifth rib is located:
- superior to the sixth rib;
- inferior to fourth rib;
- lateral to the fifth costal cartilage and fourth and fifth thoracic vertebrae.
It articulates with the:
- fifth costal cartilage at the fifth costochondral joint;
- fourth and fifth thoracic vertebrae at the fifth costovertebral joint.
Ossification
Ossification of the fifth rib occurs ossification centers found in the:
- body, which appears in utero during the second month;
- head, which appears during puberty;
- tubercle, which appears during puberty.
The ossification centers for the head and tubercle fuse with the body of the fifth rib within the fourteenth to twentieth years (Cunningham, Scheuer and Black, 2016).
Variations
In some individuals:
- the fifth rib may be fused with adjacent ribs;
- the costal end of the fifth rib may be bifid in appearance (Tubbs, Shoja and Loukas, 2016).
Surface Anatomy
The fifth rib is easily palpated and is located by palpating three ribs down from the second rib.
List of Clinical Correlates
- Fracture of fifth rib
- Flail chest
- Poland syndrome
- Asphyxiating thoracic dysplasia/Jeune syndrome
References
Cunningham, C., Scheuer, L. and Black, S. (2016) Developmental Juvenile Osteology. Elsevier Science.
Tubbs, R. S., Shoja, M. M. and Loukas, M. (2016) Bergman's Comprehensive Encyclopedia of Human Anatomic Variation. Wiley.
Learn more about this topic from other Elsevier products
Rib Cage
The rib cage forms the bony margins of the chest wall and is composed of the ribs, costal cartilages, sternum and thoracic vertebrae.
