| Physiologic requirements to perform work. | |
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MedLine Citation:
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PMID: 6421217 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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In order to perform, exercising muscle must be provided with an appropriate blood flow, and the composition of the incoming blood must be kept within acceptable limits. The circulatory system maintains flow by increasing cardiac output and reducing supply to many beds (such as the splanchnic circulation), while the lung regulates arterial O2 and CO2 levels by adjusting alveolar ventilation to metabolic needs. In the process, the function of many organs is temporarily sacrificed or depressed, which means that: (1) a hierarchy of functions has to be established, and (2) some compromises among the numerous needs of the exercising muscle must be made. As a result of these readjustments, the heart and lungs of the normal subject are able to provide all the support that the exercising muscle requires. It is the peripheral machinery that fails first, as demonstrated by the switch to anaerobic metabolism while blood pressure is actually increased, and O2 and CO2 levels are maintained. Thus, if the exertion level of a patient is limited by his central circulation or by his respiration, there is a definite decrement in the functional capacity of that system. |
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Authors:
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L E Farhi |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: The American review of respiratory disease Volume: 129 ISSN: 0003-0805 ISO Abbreviation: Am. Rev. Respir. Dis. Publication Date: 1984 Feb |
Date Detail:
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Created Date: 1984-03-22 Completed Date: 1984-03-22 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 0370523 Medline TA: Am Rev Respir Dis Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: S4-5 Citation Subset: AIM; IM; S |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Carbon Dioxide
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blood Cardiac Output Cardiovascular Physiological Phenomena Exercise Test Humans Muscles / blood supply, physiology Oxygen / blood Physical Exertion* Respiration |
| Chemical | |
Reg. No./Substance:
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124-38-9/Carbon Dioxide; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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