Dual blood supply

At the crossroads between the digestive tract and the rest of the body resides the largest solid organ of the body the hver. Because of its interposition, the hver has a dual blood supply. 

Bogousslavsky et al. 1988). Posterior choroidal artery infarcts result in visual field defects, variable sensory loss, hemiparesis, dystonia, hand tremor and occasionally amnesia and aphasia. Visual field defects, commonly quadrantanopia or hemianopia, are found if the lateral posterior choroidal arteries branches are involved in isolation. Unusual field defects such as homonymous horizontal sec-toranopia or wedge shaped homonymous hemianopia, may also be found and may be explained by the dual blood supply to the lateral geniculate body by... 

The liver plays many crucial roles in metabolism and elimination. These functions are facilitated by its anatomy and location, and its generous dual blood supply (as covered in Chapter 1). The liver is composed of a variety of cells, each contributing to overall function, which can be generally described as the regulation of the concentration of solutes in blood that affect the functions of all the other organs of the body. This regulation is achieved by the uptake, metabolism. 

As mentioned above, the liver has a dual blood supply. The hepatic artery delivers material from the systemic circulation and the portal blood flow delivers directly from the gastrointestinal system. The portal system is involved in the first pass effect , where the nutrients and xenobiotics that are absorbed from the stomach and intestines are filtered through the liver before reaching the systemic circulation (Treinen-Moslen, 2001). The space of Disse allows close contact between circulating plasma, plasma proteins, and hepatocytes, allowing for rapid diffusion of lipophilic compounds across the hepatocyte membrane. Some compounds are specifically taken up by sinusoidal transporters, including... 

The liver has a dual blood supply. Its principal afferent (incoming) blood vessel is the portal vein, which drains the capillary beds of the intestine and spleen at a rate of 1100 ml min ( 75% of the... 

The dual blood supply to the lungs is from the pulmonary artery and the bronchial arteries. 

Due to the dual blood supply to the liver, patients withblunthepaticinjuries (BHI) are ideal candidates for TAE, with success percentages of TAE reported to be as high as 98%. Complication rates of hepatic TAE are low, although one must keep in mind that necrosis can occur if portal venous supply is also disrupted due to trauma. In a retrospective study of 21 paediatric trauma patients with BHI, 18 patients could be managed conservatively, two of whom successfully underwent TAE in order to stop haemorrhage (Ohtsuka et al. 2003). 

Background. Biliary complications both intra- and extrahepatic following administration are due to the embolic and radiation induced necrosis of the biliary ducts [29]. In contrast to the normal liver parenchyma, the intrahepatic bile ducts do not have a dual blood supply and are fed exclusively from the hepatic arterial branches that give off a vascular plexus (peribiliary capillary plexus) around the bile ducts. This microscopic peribiliary arterial plexus has a similar diameter to that of the microspheres (10-60 pm, mean 35 pm). Therefore, ischaemia of the intrahepatic bile ducts can occur after radioembolization [25]. 

Differences in segmental arterial supply probably also impact on the risk of infarction. The rectum is likely to tolerate embolization better than other regions since it has a dual blood supply with the superior hemorrhoidal artery off of the inferior mesenteric artery and middle hemorrhoidal arteries arising from the internal iliac circulation. This translates into increased potential for collateral blood flow and thus decreased risk of ischemia. The cecum may be more prone to ischemia since there is not a well developed arcade along the mesenteric border of the cecum and instead there are separate anterior and posterior cecal branches. The tissue supplied by these individual branches may be more susceptible to ischemia and in fact infarction of the cecum (even after microcatheter embolization) has been reported [13]. 

The Kver is a unique organ with dual blood supply. It derives 70%-80% of its supply from the portal vein and the remaining 20%-30% from the hepatic artery. Malignant tumors in the liver receive nearly all their nourishment from the hepatic arterial supply, while the normal hepatocytes are predominantly nourished by the portal venous supply. These observations are the basis for the development of transarte-rial therapy for hepatic neoplasm while preserving normal hepatic function. 

The liver receives a dual blood supply fromboth the hepatic arteries and the portal vein. Although good collateral flow exists, necrosis can occur if enough arterial supply is occluded at the time of embolization. Therefore, it is wise to assess the direction of blood flow in the portal vein because hepatofugal flow may increase the risk of infarction. One should be cautious and superselective when embolizing in the presence of portal vein thrombosis. 

The vesicles play a dual role they maintain a ready supply of catecholamines at the nerve terminal that is available for immediate release, and they mediate the process of release. When an action potential reaches the nerve terminal, Ca channels open, allowing an influx of Ca, which promotes the fusion of vesicles with the neuronal membrane. The vesicles then discharge their soluble contents, including the neurotransmitters, ATP, chromogranins, and DBH, into the extraneuronal space by the process of exocytosis. In some cases, the catecholamines affect other neurons. In other cases, they circulate in the blood and initiate responses in peripheral tissues. 

Thermooptical detection has been combined with CE and used for protein and peptide Edman degradation sequencing detection, native protein detection, as well as the analysis of derivatized amino acid mixtures. " Frequency-doubled argon-ion lasers have been employed to supply an UV (257 nm) pump beam for the analysis of dansylated amino acids as well as the analysis of etopside and etopside phosphate in human blood plasma. In addition, two-color thermooptical absorbance detectors have been constructed, where each laser serves a dual role of pump and probe this system can be used to detect analytes that absorb in differing regions of the electromagnetic spectrum. 

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