Bone: First rib
First rib.
Latin	costa prima
Gray's	subject #28 125

The first rib is the most curved and usually the shortest of all the ribs; it is broad and flat, its surfaces looking upward and downward, and its borders inward and outward.

The head is small, rounded, and possesses only a single articular facet, for articulation with the body of the first thoracic vertebra.

The neck is narrow and rounded.

The tubercle, thick and prominent, is placed on the outer border.

There is no angle, but at the tubercle the rib is slightly bent, with the convexity upward, so that the head of the bone is directed downward.

The upper surface of the body is marked by two shallow grooves, separated from each other by a slight ridge prolonged internally into a tubercle, the scalene tubercle, for the attachment of the Scalenus anterior; the anterior groove transmits the subclavian vein, the posterior the subclavian artery and the lowest trunk of the brachial plexus. Behind the posterior groove is a rough area for the attachment of the Scalenus medius.

The under surface is smooth, and destitute of a costal groove.

The outer border is convex, thick, and rounded, and at its posterior part gives attachment to the first digitation of the Serratus anterior.

The inner border is concave, thin, and sharp, and marked about its center by the scalene tubercle.

The anterior extremity is larger and thicker than that of any of the other ribs.

[edit] See also

• Subclavius muscle

[edit] Additional images

Anterior surface of sternum and costal cartilages.	Sternoclavicular articulation. Anterior view.	The anterior vertebral muscles.	The internal carotid and vertebral arteries. Right side.
Thoracic portion of the sympathetic trunk.	Transverse section through the upper margin of the second thoracic vertebra.

[edit] External links

• first+rib at eMedicine Dictionary

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.

v • d • e Bones of torso (TA A02.2,3, GA 2.96-128) Sternum Suprasternal notch, Manubrium, Sternal angle, Body of sternum, Xiphisternal joint, Xiphoid process Rib specific ribs (1, 2, 9, 10, 11, 12, true – 1–7, false – 8–12, floating – 11–12) · parts (Angle, Tubercle, Costal groove, Neck, Head) Superior thoracic aperture · Inferior thoracic aperture · Intercostal space · Thoracic wall/Thoracic cage Vertebra General structures body of vertebra, vertebral arch (pedicle, lamina, vertebral notch), foramina (vertebral, intervertebral), processes (transverse, articular/zygapophysis, spinous), spinal canal Cervical vertebrae C1 (anterior arch, posterior arch, lateral mass), C2 (dens), C3, C4, C5, C6, C7 anterior tubercle, posterior tubercle, foramen transversarium Thoracic vertebrae T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12 costal facets (superior, inferior, transverse) Lumbar vertebrae accessory process, mammillary process, L5 Sacrum pelvic surface (anterior sacral foramina), dorsal surface (posterior sacral foramina, median sacral crest, medial sacral crest, lateral sacral crest), lateral surface (sacral tuberosity), base, sacral hiatus · presacral space · sacral promontory · sacral canal  · ala of sacrum · sacrovertebral angle Coccyx

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