RECENT investigations of the conjunctival and nail-bed microcirculation indicate that certain changes in the small blood vessels and the circulating blood are frequently associated with disease. Straight, unkinked arterioles, tortuous veins, and micropools have been observed by Landau and Davis' in subjects with arteriosclerosis. Congestion of the venules and capillaries are seen in diabetes me...

Surface wave dynamics of vertical falling films under monochromatic-frequency flowrate-forcing perturbations is computed by the direct simulation of Navier–Stokes equations using the Volume of Fluid (VOF) method to track free surfaces and the Continuum Surface Force (CSF) model to account for dynamic boundary conditions at free surfaces. The numerical VOF–CSF model is completely formulated, and...

The present work numerically simulates the flow of a single isolated liquid plug (of glycerine and water, respectively) flowing in a round capillary tube (ID = 2.0 mm), to understand its local thermal transport behavior. When an isolated liquid plug moves in a capillary tube there is a difference in the advancing and receding dynamic contact angles of the two menisci, respectively. This has bee...

Factors regulating pressure and flow in the lungs are reviewed with particular emphasis on their role in regulating blood flow velocity and distribution within the lung capillaries. The behaviour of the pulmonary arterial, system, alveolar capillaries, and pulmonary venous system are considered individually. The effect of heart disease on lung capillary blood flow is examined.

The extraction of O-labeled water by the brain during a single capillary transit was studied in vivo in 20 adult rhesus monkeys by external detection of the time course of the tracer subsequent to the internal carotid injection of 0.2 ml of whole blood labeled with H,O. The data showed that labeled water does not freely equilibrate with the exchangeable water in the brain when the mean cerebral...

The PO2 at this site where erythropoietin release is regulated should vary only when the hemoglobin concentration changes in capillary blood. The kidney cortex is an ideal location for this O2 sensor for four reasons. First, it extracts a small proportion of the oxygen that is delivered in each liter of blood; this makes the PO2 signal easier to recognize. Second, there is a constant ratio of t...

Lungs harvested from cadaveric circulation-arrested donors may increase the donor pool for lung transplantation. To determine the degree and time course of ischemia-reperfusion injury, we evaluated the effect of O2 ventilation on capillary permeability [capillary filtration coefficient (Kfc)], cell viability, and total adenine nucleotide (TAN) levels in in situ circulation-arrested rat lungs. K...

Leptin is secreted into the gastric juice by epithelial Chief cells and reaches the duodenum in a biologically intact active form. We assessed the possibility that this gastric leptin crosses the intestinal mucosa by transcytosis through enterocytes to reach blood circulation. Endogenous gastric leptin secretion was triggered by cholinergic stimulation. In another set of experiments, recombinan...

In quantitative functional neuroimaging with positron emission tomography (PET) and magnetic resonance imaging (MRI), cerebral blood volume (CBV) and its three components, arterial, capillary, and venous blood volumes are important factors. The arterial fraction for systemic circulation of the whole body has been reported to be 20-30%, but there is no report of this fraction in the brain. In th...

The amount of tissue perfused, as determined from the difference in volume of distribution between a diffusible indicator (125I-antipyrine) and an intravascular indicator (131 I-albumin) was measured at different values of coronary flow, perfusion pressure, and vasomotor tone in the working left ventricle of an open-chest dog. Coronary pressure and flow were regulated independently from the sys...