Arteries aorta

Haupt-satz, m. fundamental principle or law main theorem axiom, -schalter, m. main (or master) switch, -schlagader, /. main artery aorta, -schluss, m. (Elec.) main circuit. -schliissel, m. master key. -schnitt, m. principal section, -schwlngung, /. principal vibration, -serie, /. principal series, -tlcherung,/. (Elec.) main fuse, main cutout. 

Hugod, C. 1979. Effect of exposure to 0.5 ppm hydrogen cyanide singly or combined with 200 ppm carbon monoxide and/or 5 ppm nitric oxide on coronary arteries, aorta, pulmonary artery, and lungs in the rabbit. Int. Arch. Occup. Environ. Health 44 13-23. 

D Located in brain and arteries (aorta, coronary, mesenteric) Maintain resting BP Vasopressor and hypertensive responses Coronary vasoconstriction... 

Removal of noninfected leads is not indicated (Class III) if patients have a life expectancy of less than 1 year and in patients with known anomalous placement of leads through structures other than normal venous and cardiac structures (e.g., subclavian artery, aorta, pleura, atrial or ventricular wall, or mediastinum) or through a systemic venous atrium or systemic ventricle. Additional techniques including surgical backup may be used if the clinical scenario is compelling. 

In addition to its internal blood flow operation, the heart has its own system of blood vessels to keep the muscle wall of the heart, the myocardium, supphed with oxygenated blood (Fig. 3a). The coronary arteries, which branch from the aorta to the right and left sides of the heart, are vital to maintaining that supply. The heart is an extraordinary electromechanical muscle that can be trained to increase blood flow to the body sixfold. It can range from 5 to 30 L /min during exertion. 

Grafts are also frequently employed in the upper part of the body to reconstmct damaged portions of the aorta and carotid arteries. In addition, grafts are used to access the vascular system, such as in hemodialysis to avoid damage of vessels from repeated needle punctures. Most grafts are synthetic and made from materials such as Dacron or Teflon. Less than 5% of grafts utilized are made from biological materials. 

They also seeded autologous vSMC and ECs obtained from ovine carotid arteries to study autologous tissue-engineering blood vessels in the descending aorta of juvenile sheep. They found that after three months implantation, grafts were fully patent, without dilatation, occlusion, or intimal thickening. A continuous luminal EC layer was formed. However, after six months ... 

FIGURE 4.6 The NeuroFlo device with its dual balloon catheter uniquely designed for partial occlusion of the aorta above and below the origin of the renal arteries. 

Coronary artery bypass graft surgery Thoracic surgery whereby parts of a saphenous vein from a leg or internal mammary artery from the arm are placed as conduits to restore blood flow between the aorta and one or more coronary arteries to bypass the coronary artery stenosis (occlusion). 

Percutaneous coronary intervention A minimally invasive procedure whereby access to the coronary arteries is obtained through the femoral artery up the aorta to the coronary os. Contrast media is used to visualize the coronary artery stenosis using a coronary angiogram. A guidewire is used to cross the stenosis and a small balloon is inflated and/or stent is deployed to break up atherosclerotic plaque and restore coronary artery blood flow. The stent is left in place to prevent acute closure and restenosis of the coronary artery. Newer stents are coated with antiproliferative drugs, such as paclitaxel and sirolimus, which further reduce the risk of restenosis of the coronary artery. 

In Apo E-deficient animals fed a normal chow diet, fatty streaks are first observed in the proximal aorta at 10 to 12 weeks (15). The xanthoma that forms in the intima contains foam cells and is often called the early atherosclerotic lesion and is critically dependent on monocytes. Smooth muscle cells (SMCs) arrive in the intima at approximately 15 weeks and form a fibrous cap around 20 weeks (16). By 36 weeks, lumen narrowing occurs in the external branches of the carotid artery (incidence -75%), but the lumen size is maintained in the aorta. Lumen narrowing, or stenosis, does not correlate with plaque size but... 

The semilunar valves separate the ventricles from their associated arteries. The pulmonary valve is found between the right ventricle and the pulmonary artery and the aortic valve is found between the left ventricle and the aorta. These valves prevent backward flow of blood from the pulmonary artery or the aorta into their preceding ventricles when the ventricles relax. The semilunar valves also have three cusps. There are no valves between the venae cavae or the pulmonary veins and the atria into which they deliver blood. The closure of the valves causes the "lub-dub" associated with the heart beat. Tire first heart sound, or the "lub," occurs when the ventricles contract and the AV valves close. The second heart sound, or the "dub," occurs when the ventricles relax and the semilunar valves close. 

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