autoregulation


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Related to autoregulation: heterometric autoregulation

autoregulation

 [aw″to-reg″u-la´shun]
control of certain phenomena by factors inherent in a situation; specifically, (1) maintenance by an organ or tissue of a constant blood flow despite changes in arterial pressure, and (2) adjustment of blood flow through an organ in accordance with its metabolic needs.
heterometric autoregulation those intrinsic mechanisms controlling the strength of ventricular contractions that depend on the length of myocardial fibers at the end of diastole.
homeometric autoregulation those intrinsic mechanisms controlling the strength of ventricular contractions that are independent of the length of myocardial fibers at the end of diastole.

au·to·reg·u·la·tion

(aw'tō-reg'yū-lā'shŭn),
1. The tendency of the blood flow to an organ or part to remain at or return to the same level despite changes in the pressure in the artery that conveys blood to it.
2. In general, any biologic system equipped with inhibitory feedback systems such that a given change tends to be largely or completely counteracted; for example, baroreceptor reflexes form a basis for autoregulation of the systemic arterial blood pressure.

autoregulation

A general term for a locally controlled feedback process—e.g., the regulation of a gene encoding a transcription factor by its own gene product.

au·to·reg·u·la·tion

(aw'tō-reg-yū-lā'shŭn)
1. The tendency of the blood flow to an organ or part to remain at or return to the same level despite changes in the pressure in the artery which conveys blood to it.
2. In general, any biologic system equipped with inhibitory feedback systems such that a given change tends to be largely or completely counteracted; e.g., baroreceptor reflexes form a basis for autoregulation of the systemic arterial blood pressure.
References in periodicals archive ?
Relationship between autoregulation and nitrate inhibition of nodulation in soybeans.
Given that the autoregulation capability of the brain is important for maintaining optimal cerebral perfusion, it can be suggested that the autoregulation mechanism in different patient groups with different GCS scores should be evaluated and different positions should be investigated in future studies.
In pathological conditions, cerebral autoregulation may become impaired.
Increase in cerebral blood flow following revascularisation, without reactive cerebral vasoconstriction, can lead to vasogenic cerebral oedema in Moyamoya disease due to impaired cerebral autoregulation and blood brain barrier.
This patient had hypertension that could not be controlled because of renal disease, so adequate cerebral perfusion was achieved with higher arterial blood pressures; the cerebral autoregulation curve was cosidered to have shifted to the right.
(22,23) Findings from the current study, as well as those from others, suggest that further study with larger samples into these seemingly disparate effects of vasopressors on cerebral and peripheral microcirculation is warranted, as well as examination of a mechanistic explanation, including the role of intact or impaired autoregulation, the ability of vasopressors to cross the blood-brain barrier, and the integrity of this barrier after aSAH.
Transcranial Doppler (TCD) provides data on cerebral circulation and cerebral autoregulation [8, 21].
This concept of building a model allows to check the validity of previously made assumptions about the relationship of the main parameters in the operation of the circuit without using models of specific power modules and building a complex system of their control and autoregulation.
Currently, autoregulation of blood vessels is considered to play a critical role in the neuronal protection after ischemia during the hypercapnia and hypotension condition (5,6).
(2) A recent report summarizes small, nonhomogenous studies of near-infrared spectroscopy for frontal lobe oxygenation during liver transplantation, identifying impaired cerebral autoregulation, cerebral deoxygenation during the anhepatic phase, and cerebral hyperoxygenation with graft reperfusion.
Cytotoxic cerebral oedema causes impaired cerebral autoregulation and an increase in cerebral blood flow that results in diffusion restricted stroke-like white matter, insular and perirolandic region lesions (4,5).
In addition, recent studies have investigated the effect of head impact on dynamic cerebral autoregulation, the regulator of CBF (8, 17, 18).

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