Ribs. The Classification of Human Ribs.

The upper seven ribs are so-called "true ribs" as they have their cartilages directly attached to the sternum. Other (from 8th to 12th) are called "false ribs" as they attach to the sternum via other ribs cartilage. The last two (11th & 12th) are not attached to the sternum at all and, therefore, are called "floating ribs."

Other classifications subdivide ribs into typical and atypical. Typical ribs (from the 3rd to 9th) have common features that make it challenging to identify their position (for example, to distinguish between 6th and 7th ribs, etc.). In contrast, atypical could be identified with relative ease.


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Thorax. Anterior view The frontal view of the rib cage with comments
The front view of the thorax. True, false, floating, typical, and atypical ribs.

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Typical ribs and their articulation with vertebra Top view of the typical rib and thoracic vertebra with comments
Top view of the right and left typical rib (7th) with the thoracic vertebra VII.
The list of terms: Costa – Rib
Vertebra thoracica – Thoracic vertebra
Caput costae – Head of rib
Collum costae – Neck of rib
Tuberculum costae – Costal tubercle
Corpus costae – Body (shaft) of the rib

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Typical rib. Oblique view Typical rib and articulating thoracic vertebra with the terminology comments
Oblique view of the typical (7th) rib.

The list of terms: Costa vera – True rib
Vertebra thoracica – Thoracic vertebra
Caput costae – Head of rib
Facies articularis capitis costae – Articular surface on head of rib
Collum costae – Neck of rib
Corpus costae – Body of rib
Angulus costae – Angle of rib
Sulcus costae – Costal groove

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Joints between the rib and thoracic vertebra Costovertebral joints. Articulation surfaces with comments
The relations between a typical rib and thoracic vertebrae. The head of each typical rib articulates with two thoracic vertebrae, and the articular facet of costal tubercle articulates with the transverse process of the lower vertebra.
The list of terms: Fovea costalis inferior – Inferior costal facet
Fovea costalis superior – Superior costal facet
Facies articularis capitis costae – Articular surfaces on head of rib
Crista capitis costae – Interarticular crest on head of rib
Facies articularis tuberculi costae – Articular facet of costal tubercle
Fovea costalis processus transversi – Costal facet of transverse process

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Back view of the typical rib Head and neck of the rib with terminology comments
The back view of the typical rib. Note the two articular surfaces on the rib's head that articulates with two adjacent vertebrae and the interarticular crest facing the vertebral disc.
The list of terms: Caput costae – Head of rib
Facies articulares capitis costae – Articular surfaces on head of rib
Crista capitis costae – Interarticular crest on head of rib
Collum costae – Neck of rib
Crista colli costae – Crest of neck of rib
Facies articularis tuberculi costae – Articular facet of costal tubercle
Tuberculum costae – Costal tubercle
Angulus costae – Angle of rib
Sulcus costae – Costal groove

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First and second rib Anatomical structures of the first and second ribs
The top view of the first and second rib. Both ribs are atypical: the first rib is short and flat, and has no interarticular crest on the head since it articulatee with only one thoracic vertebra. But the second rib has prominent rounded tuberosity for attachment of the serratus anterior muscle.
The list of terms: Costa prima – First rib
Tuberculum musculi scaleni anterioris – Tubercle for anterior scalene muscle
Sulcus arteriae subclaviae – Groove for subclavian artery
Sulcus venae subclaviae – Groove for subclavian vein
Costa secunda – Second rib
Tuberositas musculi serrati anterioris – Rougheness for serratus anterior muscle

Download PNG image Eleven and twelve rib
Dorsal view of the two lowermost ribs. Both are atypical since they lack the neck, the costal tubercle, and the articular facet of the costal tubercle. Also, the head of the 11th and 12th rib has no interarticular crest because of the articulation with the single corresponding vertebra.

360° rotation of the human ribs

First published: 15/Jun/2020
Last update: 26/Aug/2020