Quick Facts
Location: Thoracic cage.
Bone Type: Flat bone.
Key Features: Head, neck, tubercle, body, angle, and costal groove.
Articulates With: Second and third thoracic vertebrae, third costal cartilage.
Arterial Supply: Anterior intercostal branches of internal thoracic and posterior intercostal arteries.
Related parts of the anatomy
Key Features & Anatomical Relations
The third 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. It does not have any extra bony features.
The third 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 third rib is located:
- superior to the fourth rib;
- inferior to second rib;
- lateral to the third costal cartilage and second and third thoracic vertebrae.
It articulates with the:
- third costal cartilage at the third costochondral joint;
- second and third thoracic vertebrae at the third costovertebral joint.
Ossification
Ossification of the third rib occurs at 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 third rib within the fourteenth to twentieth years (Cunningham, Scheuer and Black, 2016).
Variations
In some individuals:
- the second rib may be fused with adjacent ribs;
- the costal end of the second rib may be bifid in appearance (Tubbs, Shoja and Loukas, 2016).
Surface Anatomy
The third rib is easily palpated and is located by palpating one rib down from the second rib.
List of Clinical Correlates
- Fracture of third 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
PIRCM after age 3 is abnormal and can be reliably used as a sign of abnormal physiology (e.g., increased upper airway resistance).
