How the heart develops : a visual approach /
| Main Author: | |
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| Format: | eBook |
| Language: | English |
| Published: |
San Rafael, Calif. (1537 Fourth Street, San Rafael, CA 94901 USA) :
Morgan and Claypool,
[2009]
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| Series: | Colloquium digital library of life sciences.
Colloquium series on the cell biology of medicine. # 1. |
| Subjects: | |
| Online Access: | Connect to the full text of this electronic book |
| Abstract: | With possible exception of the atomic clock, the heart may be the most perfect machine ever devised. How it develops from a simple embryonic tube is a fascinating story of biology and lends a great deal of insight into the source of heart defects that affect children and adults alike. Central to this entire lecture is the fact that the fetus resides in an aquatic environment. Oxygenated blood arrives from the placenta and deoxygenated returns to the placenta (Figure 1). The lungs play no role in delivering oxygen or removing carbon dioxide to or from the circulation. Thus, the fetus mainly (but not exclusively) requires a three-chambered heart rather than the four-chambered heart that we are all familiar with. This resembles fish circulation in which blood leaves the heart into an aortic sac from which emanate the aortic arches that deliver blood to the gills, where it is oxygenated and CO2 is removed. Blood then goes to the dorsal aortae for nourishing the body tissues. In a fish there is no need for a four-chambered heart, since fish do not use lungs to aerate the blood or remove CO2 (Movie 1). Although the fetus lacks gills and still develops a four-chambered heart, much of fetal circulatory physiology depends on a "quasi-three-chambered circulation" that bypasses the pulmonary circulation. Upon birth, this "aquatic" circulation must change within minutes to permit lung function. The topics to follow trace how this circulation develops and how it changes upon birth. |
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| Item Description: | Electronic resource. Part of: Colloquium digital library of life sciences. Series from website. Title from PDF title page (viewed on March 16, 2010). |
| Physical Description: | 1 online resource (ix, 68 pages) : illustrations Also available in printing. |
| Format: | Mode of access: World Wide Web. System requirements: Adobe Acrobat reader. |
| Bibliography: | Includes bibliographical references (pages 53) and index. |
| ISBN: | 9781615040018 (electronic bk.) |
| ISSN: | 2153-0521 ; |
| DOI: | 10.4199/C00001ED1V01Y200904CBM001 |
| Access: | Abstract freely available; full-text restricted to subscribers or individual document purchasers. |