vascular resistance


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Related to vascular resistance: Peripheral vascular resistance

resistance

 [re-zis´tans]
1. opposition, or counteracting force, as opposition of a conductor to passage of electricity or other energy or substance.
2. the natural ability of a normal organism to remain unaffected by noxious agents in its environment; see also immunity.
3. in psychology or psychiatry, conscious or unconscious defenses against change, preventing repressed material from coming into awareness; they can take such forms as forgetfulness, evasions, embarrassment, mental blocks, denial, anger, superficial talk, intellectualization, or intensification of symptoms. It occurs because the blocked association or understanding would be too threatening to face at this point in the therapy; identification of what point the resistance comes at can be an important indicator of the patient's unconscious patterns.
airway resistance the opposition of the tissues of the air passages to air flow: the mouth-to-alveoli pressure difference divided by the rate of air flow. Symbol RA or RAW.
androgen resistance resistance of target organs to the action of androgens, resulting in any of a spectrum of defects from a normal male phenotype in which men have normal genitalia but infertility to complete androgen resistance in which the individual has a female phenotype. Complete androgen resistance is an extreme form of male pseudohermaphroditism in which the individual is phenotypically female but is of XY chromosomal sex; there may be rudimentary uterus and tubes, but the gonads are typically testes, which may be abdominal or inguinal in position. Called also testicular feminization and testicular feminization syndrome. Incomplete androgen resistance is any of various forms less than the complete type, manifested by a male phenotype with various degrees of ambiguous genitalia such as hypospadias and a small vaginal pouch, a hooded phallus, or a bifid scrotum that may or may not contain gonads.
drug resistance the ability of a microorganism to withstand the effects of a drug that are lethal to most members of its species.
insulin resistance see insulin resistance.
multidrug resistance (multiple drug resistance) a phenomenon seen in some malignant cell lines: cells that have developed natural resistance to a single cytotoxic compound are also resistant to structurally unrelated chemotherapy agents. Called also cross-resistance.
peripheral resistance resistance to the passage of blood through the small blood vessels, especially the arterioles.
pulmonary vascular resistance the vascular resistance of the pulmonary circulation; the difference between the mean pulmonary arterial pressure and the left atrial filling pressure divided by the cardiac output. Called also total pulmonary vascular resistance.
total peripheral resistance the vascular resistance of the systemic circulation: the difference between the mean arterial pressure and central venous pressure divided by the cardiac output.
total pulmonary resistance (total pulmonary vascular resistance) pulmonary vascular resistance.
vascular resistance the opposition to blood flow in a vascular bed; the pressure drop across the bed divided by the blood flow, conventionally expressed in peripheral resistance units. Symbol R or R.

vas·cu·lar re·sis·tance

(vas'kyū-lăr rē-zis'tăns)
Resistance to flow within the smaller vessels, which is also determined by blood viscosity and the length of the vessels.

vascular resistance,

n the degree to which the blood vessels impede the flow of blood. High resistance causes an increase in blood pressure, which increases the workload of the heart.
References in periodicals archive ?
Flap valve double patch closure of ventricular septal defects in children with increased pulmonary vascular resistance.
Rezk et al [10] assessed some mechanisms of BP control after a resistance exercise session and observed decrease in the systolic volume and cardiac output, no change of the peripheral vascular resistance and, consequently, a reduction in BP.
Volatile agents may unfortunately lead to a dose-dependent depression of cardiac contractility and reduction in systemic vascular resistance (SVR), which may reduce systemic blood pressure and precipitate right ventricular ischaemia and failure.
1) In hypoglycemia, the total peripheral vascular resistance falls by as much as 20%, and there is a rise in splanchnic blood flow.
They are likely to get an increase in cardiac performance and a decrease in vascular resistance.
Arterial blood pressure (BP) and heart rate (HR) were also measured, and an index of coronary vascular resistance (CVR) was calculated as diastolic BP/CBV.
They then address the fluid mechanics of blood flow at the arterial level, discussing the rheological behavior of blood, steady flow models of vascular resistance, models of unsteady and pulsatile flow, the relationship between flow-induced stresses and the initiation and growth of athersclerosis, and flow through native heart valves and cardiac chambers, among other topics.
These animals manifest increased DDAH activity, decreased plasma ADMA concentrations, increased plasma and urinary nitrogen oxides, and decreased vascular resistance, presumably attributable to increased NO (4).
The clinical characteristics of PAH include persistently elevated pulmonary arterial pressure, in combination with normal PCWP and increased pulmonary vascular resistance.
The constancy of diastolic blood pressure during the fifties together with an increase in systolic pressure points to a combined effect of increased peripheral vascular resistance and large artery stiffness.
Triiodothyronine also decreases systemic vascular resistance by dilating the resistance arterioles.