| Autor: |
Najafi, N., Ashtiyani, S. C., Khamnei, S. |
| Předmět: |
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| Zdroj: |
Arak Medical University Journal; Fall2011, Vol. 14 Issue 3, p106-115, 10p |
| Abstrakt: |
Arterial baroreceptors are located in the carotid and aortic arteries and play a pivotal role in rapid control of cardiovascular system. The purpose of this article is to review the effects of baroreceptors stimulation on heart rate at rest and during exercise and cerebral blood flow rate in young and middle aged male and female individuals. There is ample evidence indicating that the arterial baroreflex remains functional during exercise by readjustment which is in direct relation to the intensity of exercise. These adjustments might be done through somatosensory afferents from peripheral regions of the body, pathways obeying central command neurons, or vasopressin and oxytocin pathways that converge into the nucleus tractus solitarii (NTS). Cerebral blood flow autoregulation is a process by which cerebral blood flow is maintained at a fixed rate despite fluctuations in cerebral perfusion pressure. Similar to that in young individuals, this mechanism, despite fluctuations in baroreceptors sensitivity, stabilizes cerebral blood flow rate in a certain range in middleaged individuals, although with aging the absolute cerebral blood flow rate decreases in both genders. In addition, it has also been shown that after termination of carotid baroreceptors stimulation, heart rate increases which is known as postvagal tachycardia (PVT). It seems that two components, adrenergic and non-adrenergic, are involved in PVT. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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