Aorta tube

Plastics have made many major contributions to the contemporary scene. Health-care professionals depend on plastics for everything from intravenous bags to wheelchairs, disposable labware to silicone body parts, etc. The diversity of plastics allows them to serve in many ways, improving and prolonging lives, such as a braided, corrugated Dacron (Du Pont s polyester) aorta tube (24). 

Blaustein A question is the aorta an artery It is a big tube that doesn t have to do much a lot of the time. It might have less SR than smaller arteries. 

Human P450 8A1 was cloned from aorta endothelial cells by Tanabe s group . The mRNA is widely expressed in human tissues, including ovary, heart, skeletal muscle, lung, prostate , and umbilical vein °. More recent work has shown some localization in the brain, including neuronsAnother site of expression is fallopian tubes, with expression in luminal epithelia, tubal smooth muscle, vascular endothelial cells, and vascular smooth muscle cells ". ... 

Figure 28, Duration of patency of metal tubes implanted in canine thoracic aorta or vena cava as a function of the standard electrode potential of the metal. ...

Materials such as polyvinyl alcohol, polyamide, polyacrylonitrile, polyethylene terephthalate, and polytetrafluorethylene were all tried. As long as these textile tubes were implanted in the aorta, there was little clinical difference among the materials. Most of the differences in results were due to the different textile structures used. However, biostability and availability of commercial yams did depend on the polymer chosen. 

Stephen Hales, an English clergyman and physicist, carried out a classic experiment in 1732 to determine blood pressure. He connected a U tube to the carotid artery of a mare and observed the height that blood rose in the tube. Then, using fluid dynamic principles, he calculated the velocity of blood in the aorta, force of contraction, and stroke volume. This work has been the foundation of modem hemodynamics and was used by Bernoulli in his quite accurate calculation of cardiac output in 1737. 

The circulatory fluid is ejected by an electropneumatically driven ventricular pump. Downstream of the pump, an aortic valve assembly is located two different models have been built in order to offer lateral or frontal view of the prosthesis movements. Suitable stent adapters allow to test prostheses of different type and size. The aorta is a variable compliance rubber tube. Through a rigid conduit the fluid is conveyed to the laminar flow assembly which controls peripheral resistances. Aortic compliance and peripheral resistances are hydropneumatically controlled. The fluid, passing through a venous reservoir open to atmospheric pressure, reaches the left atrium. This is a rigid wall chamber in which a hydropneumatic system relates cardiac output to venous return, reproducing Frank--Starling s Law. Between atrium and ventricle there is another valve test assembly which allows to test mitral valves. 

Fig. A Cross section of the middle thoracic region of a control embryo showing the closed neural tube (top) with the paired dorsal aortae. The foregut overlies the pericardial coelom and heart. Cross section of the middle thoracic region of a hamster embryo recovered 10 hr after a teratogenic dose of sodium arsenate. The region shows retardation in approximation and fusion of the neural folds and shows flattening and exposure of the neuroectoderm. (x 350).

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