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Clinical Effects of Pollution
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 5, 2017
William J. Rea, Kalpana D. Patel
Part of the cardiovascular system, the vasa vasorum are a network of small blood vessels, that help supply larger vessels with blood. The vasa vasorum provide blood and oxygen to large arteries and veins, and returns that supply blood depleted of oxygen through the VVV eventually going to the lungs. Toxins are also delivered to the largest blood vessels in the body. The aorta depends on this support network of vasa vascular to maintain healthy function. All vessels with a wall less than 500 μm thick (or 29 cell layers) do not have vasa vasorum.357 Vasa vasorum are found in vessels 0.5 mm in diameter or greater and an arterial wall media more than 29 lamellar thick.358,359 The vasa vasorum are needed to supply large arteries and veins because of their large size. In order to effectively receive oxygen from the bloodstream, cells must be very close to a small blood vessel or capillary so that oxygen can pass into each individual cell. Most blood vessels and veins absorb oxygen from the blood flowing inside them. However, because the large pressure big arteries are by necessity so thick, their outer and middle cell layers cannot be adequately be nourished without this additional network of blood vessels to support them by providing oxygenated blood and nutrients and carrying away deoxygenated blood and toxic waste materials. This vasa vasorum network stretches from the carotid to the femoral arteries possibly beyond (Figure 2.17).
Intravascular Radiation Detectors to Detect Vulnerable Atheroma in the Coronary Arteries
Published in Robert J. Gropler, David K. Glover, Albert J. Sinusas, Heinrich Taegtmeyer, Cardiovascular Molecular Imaging, 2007
Daniel Pryma, Bradley E. Patt, H. William Strauss
In patients experiencing a major acute cardiac event (MACE), urgent catheterization defines the location and extent of the problem and delivers local therapy. Although the event is usually caused by a culprit lesion, where an occlusive thrombus formed on a ruptured plaque, coronary angioscopy has demonstrated there are typically a large number of lesions at other sites in the coronary tree (9) that have characteristics similar to the culprit lesion prior its acute rupture. This observation suggests a pancoronary arteritis (10). These lesions remain clinically silent, unless the thrombus propagates, leading to occlusion of the vessel. Since these lesions are difficult or impossible to identify angiographically, other approaches are under development. The metabolic rate of atheroma varies, but lesions with large amounts of lipid, especially oxidized low density lipoprotein, have a high metabolic rate. The high metabolic rate leads to increased vasa vasorum. The vasa vasorum are thin walled, and can rupture into the plaque, markedly increasing intralesional pressure, with subsequent loss of integrity of the cap of the plaque, and rupture of the lesion. Alternatively, some lesions erode (lose their endothelium, most likely due to apoptosis of the overlying endothelial cells), exposing the underlying thrombogenic collagen to blood, resulting in formation of thrombus with subsequent progression of stenosis or complete occlusion of the vessel.
Attenuation of streptozotocin induced high fat diet exacerbated dyslipidemia mediated hepatic and aortic injuries in male pigs by camel milk
Published in Egyptian Journal of Basic and Applied Sciences, 2023
Hadiza Bello Rilwan, Sunday Samuel Adebisi, James Abrak Timbuak, Sunday Blessing Oladele, Aliyu Muhammad, Wusa Makena, Adamu Abubakar Sadeeq
A Photomicrograph section of an aorta tissue from the control group (NC) showed normal tunica intima, tunica media, tunica adventitia, and Vasa vasorum characteristics (Figure 6a). A histological section of the aorta in the D-HFD group showed marked tunica intima ulceration, medial cystic necrosis, and some fibrinoid necrosis in the aortic medium (Figure 6b). Photomicrographs of the aorta in the D-HFD + 250 CM group displayed typical tunica intima characteristics, some calcification of the tunica media, and medial cystic necrosis (Figure 6c). Sections from the D-HFD + 500 CM group revealed normal tunica intima, tunica media, and minor disruption of the tunica adventitia (Figure 6d), while D-HFD + MET showed minor tunica intima ulceration, medial cystic necrosis, and tunica adventitia disruption (Figure 6e). For Masson’s trichrome stain, aorta from NC sections showed a normal distribution of reticular fibers in the parenchyma collagen fiber (Figure 7a). The D-HFD section revealed marked disruption/depletion of collagen fiber and extensive ulcers at the tunica intima (Figure 7b). D-HFD + 250 section exhibited remarkable collagen fiber restoration with tunica media ulceration (Figure 7c). D-HFD + 500 section demonstrated marked collagen fiber repair (Figure 7d), while D-HFD + MET aorta showed a slight improvement in collagen fiber distribution with medium ulceration (Figure 7e).
Oxygen transport in a permeable model of abdominal aortic aneurysm
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Rana Zakerzadeh, Tanja Cupac, Michael Durka
The prescribed conditions over the boundaries are summarized in this section as follows. At the inlet of the artery, we considered a fully developed and unidirectional velocity profile The flowrate was chosen to match physiological Reynolds numbers of the flow in the abdominal aorta under the resting condition (Fraser et al. 2008). At the model outlet, the reference pressure value was prescribed, which can be arbitrarily set for incompressible flow. The exterior of the arterial wall surface was modelled as an opening. This enables oxygen to either exit through the wall or to enter into the tissue. Moreover, the influence of the vasa vasorum on this boundary is modelled by imposing the partial pressure of oxygen. Experimental studies showed that the level of adventitial oxygen tension is about one half of the oxygen tension in blood (Buerk and Goldstick 1982, 1986); therefore the abluminal wall partial pressure was fixed at 50 mmHg to model the oxygen supplied by the vasa vasorum (Kemmerling and Peattie 2018). At the cross-sectional areas of the wall representing the ends of the vascular domain a zero-flux condition on the surface normal direction denoted by was prescribed.