Kidneys, surgically removed due to carcinoma, were subjected to perfusion in vitro. The perfusion distribution was studied by means of labeled microspheres injected during maximal vascular dilation and during two different norepinephrine concentrations. The perfusion concluded with injection of barium sulfate. Two-mm-thick slices of tissue were autoradiographed and microangiographed for visuali...

The effect of the heart rate and myocardial contractile force on the extravascular resistance to blood flow of the left anterior descending coronary artery (LAD) was evaluated in 15 mongrel dogs anesthetized with sodium pentobarbital. The LAD was maximally dilated by intracoronary infusion of adenosine, which precluded the influence of vasomotor tone. Increases in the heart rate and myocardial ...

The nature of the arteriolar resistance and its distribution in the body remain the fundamental problem in the study of arterial hypertension in man. Since the cardiac output is normal in this state (1), the " average arteriolar resistance " at rest must be increased. The extent to which the peripheral resistance is increased in various tissues can be determined by comparing the blood flow in t...

Vegetation growing in the water along rivers plays an important role on the hydrodynamic behavior, on the ecological equilibrium and on the characteristics of the river. It has effects on the flow resistance and, as a result, has a large impact on water levels. The influence of non-submerged vegetation on flow is not so clear as yet; it needs to be further studied. The Acorus Calmus L is a kind...

Microvascular blood flow resistance has a strong impact on cardiovascular function and tissue perfusion. The flow resistance in microcirculation is governed by flow behavior of blood through a complex network of vessels, where the distribution of red blood cells across vessel cross-sections may be significantly distorted at vessel bifurcations and junctions. In this paper, the development of bl...

Part 1. The problem and the experiments. General statement-_________________________________ Flow in irregular open channels__________________. Design of experiment_____________._...______ Experimental conditions. ______________________ Experimental results._________________________ Character of the flow; deformation of the free surface. _ _ Conditions below threshold____________________ Condit...

The quantification of flow resistance in complex natural channels continues to be a key source of uncertainty in basic research, engineering, and environmental management. This paper describes a meta-analysis of data compiled from a wide range of sources and flow conditions in mountain streams that compares the accuracy of equations developed by Jarrett (1984), Hey (1979), Bathurst (1985) and B...

We measured the flow-resistance of five commercially available 10 cm H2O expiratory positive-pressure (EPP) valves (n = five per valve type) at bias flows of between 0 and 2,000 ml/s. We found that individual valves of each type and manufacturer functioned similarly. Different valve types, however, functioned differently: with one type, system pressure was higher than rated (p less than 0.05), ...

The purpose of this study was to determine whether the acute hormone response to exercise differed between low intensity blood flow restricted resistance exercise and traditional high-intensity resistance exercise in college-aged women. A total of 13 healthy women (aged 18-25 yrs), who were taking oral contraceptives, volunteered for this randomized crossover study. Subjects performed a session...