UAMS Department of Neurobiology and Developmental Sciences Bones of the Thorax

Gross Anatomy

Bones of the Thorax

Bone Structure Description Notes
rib the bone forming the lateral thoracic wall 12 pairs; several types are described: typical or "true" ribs, "false" ribs, "floating" ribs; all three types of ribs have many features in common: head, neck, tubercle, angle, body, costal groove
head posteromedial end of the rib it articulates with demifacets of two adjacent vertebral bodies
neck the constricted region lateral to the head of the rib the neck of the rib is located between the head and the tubercle
tubercle a projection located posteroinferior and lateral to the neck of the rib it articulates with the transverse process of a vertebra
body the shaft of the rib the body is the longest part of a typical rib
angle the marked angulation of the body located just lateral to the tubercle the angle of the rib is its most posterior part
costal groove the groove on the inner surface of the inferior border of the body of the rib it accommodates the intercostal neurovascular bundle; the costal groove provides a protective function for the intercostal neurovascular bundle,
ribs 1-7 "true" ribs - those which attach directly to the sternum true ribs actually attach to the sternum by means of a costal cartilage and a true synovial joint
rib 1 the most cephalic rib it is the broadest, shortest and widest of the ribs; the scalene tubercle marks its superior surface and is an elevation between grooves for the subclavian vein & artery; the scalene tubercle is the attachment site of the scalenus anterior m.
rib 2 the rib attached to the 1st and 2nd thoracic vertebrae it articulates via a costal cartilage with the sternum at the level of the sternal angle; its superior surface is roughened by the attachments of the scalene mm.
rib 8-10 "false" ribs they articulate via costal cartilages with the costal cartilage of rib 7
rib 11-12 "floating" ribs the anterior ends of these ribs do not articulate with the sternum or the costal cartilage of the rib above; their costal cartilages are short and end in the muscle of the posterolateral abdominal wall
sternum the broad flat bone forming the anterior thoracic wall it is formed by three parts: manubrium, body, xiphoid process
manubrium the superior part of the sternum manubrium means "handle", as in the handle of a sword
jugular (suprasternal) notch a notch on the superior border of the manubrium it is located between the clavicular notches which articulate with the sternal ends of the clavicles
clavicular notch a notch on the superolateral border of the manubrium it articulate with the sternal end of the clavicle
sternal angle the junction of the manubrium and body of the sternum it is an anterior projection located at the level of the costal cartilage of rib 2; an important landmark for internal thoracic anatomy
body the middle part of the sternum it articulates with the manubrium superiorly and the xiphoid process inferiorly; laterally it articulates with the costal cartilages of ribs 2-7
xiphoid process the inferior part of the sternum xiphoid means "sword shaped"; it is variable in size, shape & ossification; it articulates with the body of the sternum superiorly

Some of the material presented in these tables is contained in the book:
MedCharts Anatomy by Thomas R. Gest and Jaye Schlesinger
Published by ILOC, Inc., New York. Copyright 1995.

The content of these tables has been edited for use in this course by Patrick W. Tank, Ph.D.
Copyright 2009, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences.
Unauthorized use is prohibited.

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