Item Type: | Article |
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Title: | Autonomic cardiovascular control.Lessons from autonomic disorders |
Creators Name: | Lu, C.C., Tung, C.S., Jordan, J., Diedrich, A. and Biaggioni, I. |
Abstract: | Disorders of the autonomic nervous system may arise in afferent or efferent pathways, and in central nuclei involved in autonomic integration. Whereas these disorders are relatively rare medical conditions, they can be extremely useful in illustrating the regulatory role of the autonomic nervous system in cardiovascular function. Here we review defects in the afferent limb of the sympathetic nervous system (baroreflex failure), in central autonomic nuclei (multiple system atrophy) and in efferent pathways (pure autonomic failure). Hypertension is observed in each of these conditions, highlighting the role of the autonomic nervous system in long term regulation of blood pressure. Patients with autonomic failure are also characterized by the absence of baroreflex function. In these patients, responses normally obscured by autonomic reflexes are amplified. There are several examples of physiological phenomena first revealed in autonomic failure patients, e.g., food ingestion induces a profound decrease in blood pressure in these patients, due to splanchnic blood pooling. Conversely, commonly used medications such as phenylpropanolamine, and evenly seemingly innocuous interventions such as water drinking, can produce dramatic increases in blood pressure in these patients. Autonomic disorders, therefore, provide a unique opportunity to understand more common abnormalities in cardiovascular regulation. |
Keywords: | Autonomic nervous system, Baroreflex, Hypertension, Shy-Drager syndrome |
Source: | Journal of Medical Science |
ISSN: | 0255-6472 |
Volume: | 23 |
Page Range: | 243-248 |
Date: | 1 January 2003 |
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