Helsinki Committee for Human Rights

 

 

 

 

 

 

 

 

Compliance (physiology)

Compliance is the ability of a hollow organ (vessel) to distend and increase volume with increasing transmural pressure or the tendency of a hollow organ to resist recoil toward its original dimensions on application of a distending or compressing force. It is the reciprocal of "elastance", hence elastance is a measure of the tendency of a hollow organ to recoil toward its original dimensions upon removal of a distending or compressing force.

Veins have a much higher compliance than arteries (largely due to their thinner walls.) Veins which are abnormally compliant can be associated with edema. Pressure stockings are sometimes used to externally reduce compliance, and thus keep blood from pooling in the legs.

Vasodilation and vasoconstriction are complex phenomena; they are functions not merely of the fluid mechanics of pressure and tissue elasticity but also of active homeostatic regulation with hormones and cell signaling, in which the body produces endogenous vasodilators and vasoconstrictors to modify its vessels' compliance. For example, the muscle tone of the smooth muscle tissue of the tunica media can be adjusted by the renin¥angiotensin system. In patients whose endogenous homeostatic regulation is not working well, dozens of pharmaceutical drugs that are also vasoactive can be added. The response of vessels to such vasoactive substances is called vasoactivity (or sometimes vasoreactivity). Vasoactivity can vary between persons because of genetic and epigenetic differences, and it can be impaired by pathosis and by age. This makes the topic of haemodynamic response (including vascular compliance and vascular resistance) a matter of medical and pharmacologic complexity beyond mere hydraulic considerations (which are complex enough by themselves).

Arterial compliance is an index of the elasticity of large arteries such as the thoracic aorta. Arterial compliance is an important cardiovascular risk factor. Compliance diminishes with age and menopause. Arterial compliance is measured by ultrasound as a pressure (carotid artery) and volume (outflow into aorta) relationship.

Compliance, in simple terms, is the degree to which a container experiences pressure or force without disruption. It is used as an indication of arterial stiffness. An increase in the age and also in the systolic blood pressure (SBP) is accompanied with decrease on arterial compliance.

Endothelial dysfunction results in reduced compliance (increased arterial stiffness), especially in the smaller arteries. This is characteristic of patients with hypertension. However, it may be seen in normotensive patients (with normal blood pressure) before the appearance of clinical hypertension. Reduced arterial compliance is also seen in patients with diabetes and also in smokers. It is actually a part of a vicious cycle that further elevates blood pressure, aggravates atherosclerosis (hardening of the arteries), and leads to increased cardiovascular risk. Arterial compliance can be measured by several techniques. Most of them are invasive and are not clinically appropriate. Pulse contour analysis is a non-invasive method that allows easy measurement of arterial elasticity to identify patients at risk for cardiovascular events.

A study concluded that arterial compliance, which diminishes with menopause, was significantly improved with red clover isoflavones. The results of another study support the hypothesis that fish oil alters vascular reactivity and favorably influences arterial wall characteristics in patients with non-insulin dependent diabetes mellitus. These direct vascular effects, expressed at the level of the vessel wall, may contribute to the cardioprotective(protective for the heart) actions of fish oil in humans. Another study concluded that one important measure of arterial health, systemic arterial compliance, was significantly improved in perimenopausal and menopausal women taking soy isoflavones to about the same extent as is achieved with conventional hormone replacement therapy.

 

 

 

 

 

 

 

 

www.helsinski.org.rs | biserkos@eunet.rs

 

 

 

 

 

 

 

 

U.S. HELSINKI COMMISSION TO HOLD HEARING ON HUMAN TRAFFICKING AND TRANSNATIONAL ORGANIZED CRIME

November 2, 2011

10:00 a.m. - 11:30 a.m.

Please join the Commission on Security and Cooperation in Europe for a hearing that explores the nexus between Transnational Organized Crime and Human Trafficking.

Organized Crime has evolved to meet the challenges of globalization and modern technology. In this evolution major international criminal organizations and smaller highly specialized groups of criminal entrepreneurs have found new ways to expand their operations and exploit human beings into slavery. To meet these challenges new national and international strategies have been placed into action, but their results remain to be seen. This continues the Helsinki Commission’s hearing series on new fronts in human trafficking. This hearing will focus on: (1) the evolving nature of Transnational Organized Crime, (2) the role of major international organized crime groups and smaller organized criminal syndicates in human trafficking, (3) identified trends, and (4) strategies to combat these organizations and prevent the trafficking of human beings.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Copyright * Helsinki Committee for Human Rights 2011