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 vena cavae are two very large-diameter veins. As with the other veins throughout the body (with the exception of the pulmonary vein), the venae cavae both carry oxygen-depleted (deoxygenated) blood from the tissues of the body to the right atrium of the heart.
In humans, because we stand upright, one vena cava is located above the other. The upper vena cava is referred to as the superior vena cava; the lower vena cava is referred to as the inferior vena cava. In other mammals, however, these same vessels are referred to as the anterior and posterior venae cavae.
The superior vena cava receives blood from the upper part of the body, including the head, neck, arms, and chest. The inferior vena cava receives blood from the legs, pelvis, and all of the structures and organs within the abdomen. Because the venae cavae carry such a large volume of blood, the diameter of each tube is the largest of any blood vessel within the body. For example, the average internal diameter of other veins is about 0.39 in (1.0 cm); the diameter of the venae cavae is about 2.39 in (6 cm). This is larger, even, than the radius of the body's largest artery, the aorta, which measures about 0.98 in (2.50 cm) in radius. The walls of the venae cavae are comparatively thin, and quite flexible.