Quick Facts
Location: Thoracic cage.
Bone Type: Flat bone.
Key Features: Head, neck, tubercle, body, angle, and costal groove.
Articulates With: Sixth and seventh thoracic vertebrae, seventh costal cartilage.
Arterial Supply: Posterior intercostal, anterior intercostal branch of internal thoracic, musculophrenic arteries.
Related parts of the anatomy
Key Features & Anatomical Relations
The seventh 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 seventh 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 seventh rib is located:
- superior to the eighth rib;
- inferior to sixth rib;
- lateral to the seventh costal cartilage and sixth and seventh thoracic vertebrae.
It articulates with the:
- seventh costal cartilage at the seventh costochondral joint;
- sixth and seventh thoracic vertebrae at the seventh costovertebral joint.
Ossification
Ossification of the seventh 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 seventh rib within the fourteenth to twentieth years (Cunningham, Scheuer and Black, 2016).
Variations
In some individuals:
- the seventh rib may be fused with adjacent ribs;
- the costal end of the seventh rib may be bifid in appearance (Tubbs, Shoja and Loukas, 2016).
Surface Anatomy
The seventh rib is easily palpated and is located by palpating five ribs down from the second rib. Counting the seventh to tenth ribs is best done from the lateral aspect of the thoracic cage.
List of Clinical Correlates
- Fracture of seventh rib
- Flail chest
- 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.
