Inflow artery

One source of calcium ions, which cause contraction of smooth muscle in arterial walls, is inflow through ion-specific channels. So, the calcium blockers block the channels, limiting inflow of calcium and keeping muscle cells in relaxed states for a longer time. 

Papaverine (Pavabid) is a nonspecihc phosphodiesterase inhibitor that increases cAMP and cGMP levels in penile erectile tissue. Papaverine is particularly known as a smooth muscle relaxant and vasodilator. Its principal pharmacological action is as a nonspecihc vasodilator of smooth muscles of the arterioles and capillaries. Various vascular beds and smooth muscle respond differently to papaverine administration both in intensity and duration. Papaverine decreases the resistance to arterial inflow and increases the resistance to venous outflow. 

Calcitonin gene-related peptide (CGRP) induces a dose-related increase in penile arterial inflow, cavernous smooth muscle relaxation, cavernous outflow occlusion, and an erectile response. CGRP plus PGEj may be an alternative to penile implants in selected patients. 

These forms relate the dependence on the system characteristics. Equation (8.13) describes the concentration c(z, t) of a solute in a tree-like structure that corresponds to the arterial tree of a mammal. Considering also the corresponding venular tree situated next to the arterial tree and appropriate inflow and outflow boundary conditions, we are able to derive an expression for the spatiotemporal distribution of a tracer inside a tree-like transport network. We also make the assumption that the arterial and venular trees are symmetric, that is, have the same volume V then, the total length is L = V/Ag The initial condition is c(z, 0) = 0 and the boundary conditions are ... 

Erectile dysfunction Alprostadil injected into the corpus caver-nosum of the penis provides effective treatment of some forms of male impotence. The drug increases arterial inflow through vasodilation and decreases venous outflow by causing relaxation of the corporal smooth muscle that occludes draining venules. Possible side effects include pain at the site of injection and, rarely, prolonged erection. 

Tc-DTPA Arterial perfusion accounts for 20%-40% of the circulation in portal hypertension, cirrhosis causes arterial perfusion to increase to over 60%. In portal vein thrombosis, only an arterial curve is visible. Liver metastasis usually displays relatively high arterial perfusion. In (rare) occlusions of the hepatic artery, only a portal venous curve is visible. When a bolus injection of 400 MBq "Tc-diethylenetriamine pentaacetic acid (DTPA) is applied, scintigraphy is able to reveal a bi-phasic time-activity curve. The initial increase of activity is produced by the arterial influence and the second peak by the portal venous inflow. Both curves can be evaluated quantitatively. (36) Perfusion scintigraphy may be useful in the case of liver trauma, TIPS, hyper-vascularized hepatic tumours and partial liver resection as well as after liver transplantation. 

Disturbed inflow hypoperfusion due to arterial, por-tovenous or combined oligaemia results in centrilobular necrosis or even anaemic liver infarction. 

Alprostadil. Alprostadil is chemically identical to the naturally occurring form of prostaglandin E and acts similar to the endogenous PGE. It induces erection by relaxation of the cavernosal smooth muscle and dilation of cavernosal arteries, which leads to increased arterial inflow and decreased venous outflow. Alprostadil has various systemic... 

Detumescence, or the progression of an erect penis to a flaccid state, results from the actions of norepinephrine, which contracts vascular smooth muscle to decrease arterial inflow to the corpora and contracts sinusoidal tissue in the corpora. As a result, venous outflow from the corpora increases. 

The residual (after all losses) inflow to the Sea gauged on the main water arteries of the delta which reach the sea edge, for the period from 1932 to 1950 was assessed by the authors of this work and by Uzbek Hydrometeorologic Service for 1951-... 

Figure 21. Relation of Ot transfer rate to inflowing (umbilical arterial) p02 in five sheep cotyledons. Small changes in p0 are seen to be associated with relatively large changes in Og transfer in any given animal.

Role of Various Factors in Placental O2 Transfer. These experiments characterize the dependence of 02 transfer and umbilical venous po2 on maternal arterial p02> fetal placental flow rate, and fetal inflowing po2 on O2 exchange in a single cotyledon of the sheep placenta and on fetal placental flow in the rabbit placenta. Each factor was studied individually while the fetal placental circulation was isolated and perfused in situ. The present findings do not apply for an intact fetus whose blood recirculates between peripheral tissues and the placenta because compensations would tend to maintain 02 transfer equal to fetal 02 consumption in this latter instance. The present data take account of changes in only a single variable. 

In the experiments described here, the maternal and fetal sides of the placenta were perfused simultaneously by an apparatus in which maternal arterial inflow and maternal venous return occur through the base of the placenta, as they do in vivo (20). 

When applied to infants, both disk and bubble oxygenators have the disadvantage of having an open or variable prime so that the venous inflow and the arterial outflow need to be precisely matched to avoid fatal shifts of fluid into or out of the patient. 

Mean transit time (MTT) is defined as the average of the transit time of blood through a given brain region. The transit time of blood through the brain parenchyma varies depending on the distance traveled between arterial inflow and venous outflow, and is measnred in seconds. Mathematically, mean transit time is related to both CBV and CBF according to the central volnme principle, which states that MTT = CBV/CBF[110, 111]. 

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