The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
The sternum is a long bony plate located in the anterior (front) region of the chest. Three distinct bones can be seen. The superior or uppermost plate is the manubrium, followed by the body or gladiolus. At the end of this series is a tiny triangular shaped bone named the xiphoid. Both muscles of the chest and costal cartilage articulate with these bones. They help anchor the ribcage for protection of the lungs and upper body organs.
The manubrium is triangular and thicker at its top than bottom. It is somewhat convex. On the anterior side, the pectoralis and sterno portion of the sterno-cleido-mastoid muscle originate. The site of attachment can be identified by the sternal notch. On the posterior surface the heads of the sterno-hyoid and sterno-thyroid muscles find their origin.
The thickest portion of the manubrium, the superior border, the pre-sternal notch, indicates the position where the sternal end of the clavicle (collar bone) articulates. On either side of this flat bone there are facets for the costal cartilage of the first pair of ribs. These lie just under the clavicle.
The long body of the gladiolus joins the manubrium at the sternal angle. It is possible to feel this ridge with the hands, which makes it useful as a locator for cardio-pulmonary resuscitation (CPR). In some people, however, this region is concave and very distinctive. Facets occur along the lateral ridges of this flat bone for articulation with costal cartilage and ribs two, three, four, and five. The inferior margin of the gladiolus supports two costal cartilage heads that then differentiate to support ribs 6-10. Ribs 11 and 12 do not articulate with the sternum.
The xiphoid process terminates the sternum. It is small and somewhat elongate. In adolescence it is cartilaginous, but ossifies in adulthood. Although tiny in size, the bone offers an attachment site for part of the seventh rib, the chondro-xiphoid ligament, and the linea alba. This bone has a highly diversified appearance from one body to another.