Adventitia

Factor VII. This is a vitamin K-dependent serine protease that functions in the extrinsic coagulation pathway and catalyzes the activation of Factors IX and X. Factor VII is present constitutively in the surface membrane of pericytes and fibroblasts in the adventitia of blood vessels, vascular endothehum, and monocytes. It is a single-chain glycoprotein of approximately 50,000 daltons. 

Meticulous care needs to be used in the application of this tissue adhesive. Only a very thin layer of adhesive should be used to assist with reapproximation of the intima and adventitia. It is important to remember that the material should not be allowed to drip into or onto critical areas such as the ostium of the coronary arteries. Inadvertent placement of this agent in such areas can result in blockage of a critical artery and a potentially fatal myocardial infarction. In addition. 

Mast cells are present in the normal human heart and even more abundant in diseased hearts [ 16-18,25,47]. Within heart tissue, mast cells he between myocytes and are in close contact with blood vessels. They are also found in the coronary adventitia and in the shoulder regions of coronary atheroma [20, 21], The density of cardiac mast cells is higher in patients with dilated and ischemic cardiomyopathy than in accident victims without cardiovascular diseases [25], Importantly, in some of these conditions there is in situ evidence of mast cell activation [16,34],... 

It has been pointed out that some of the histopatholog-ical changes in rheumatoid synovitis are similar to those noted adjacent to atherosclerotic plaques. For example, accumulation of mononuclear cells at the extraluminal surface of endothelial cells in the adventitia and the deposition of immune complexes have been reported in both diseases (Rothschild and Masi, 1982). 

The normal arterial wall consists of the intima, media, and adventitia, as illustrated in Fig. 4—3A. The endothelium is located in the intima and consists of a layer of endothelial cells that line the lumen of the artery and form a selective barrier between the vessel wall and blood contents. The internal elastic lamina separates the intima and media, where vascular smooth muscle cells are found. The vascular adventitia comprises the artery s outer layer. Atherosclerotic lesions form in the subendothelial space between the endothelial cells and internal elastic lamina. 

We carefully dissected rat tail arteries and loaded them with a Ca2+ indicator, Fluo-3. After a rectangular glass capillary was inserted into the lumen of the excised arteries, [Ca2+] in smooth muscle cells within the arterial wall was visualized using a confocal microscope. Brief electrical shocks were delivered at 5 Hz to the preparations to stimulate the sympathetic nerve network present in the adventitia. We found Ca2+ signals with diverse spatiotemporal patterns, Ca2+ waves and oscillations in individual smooth muscle cells during the sympathetic nerve stimulation (lino et al 1994). 

Tl Tumor invades lamina propria or submucosa T2 Tumor invades muscularis propria T3 Tumor invades adventitia T4 Tumor invades adjacent structures Regional lymph nodes (N)... 

See color plate.) Microscopy with 405 nm excitation reveals red fluorescence from talaporfin (LSI l/NPe6) in macrophages within atheromatous plaque on abdominal aorta in hyper- cholesterolemic rabbit, 24 hours after 5mg/kg intra- venous administration. Note green autofluorescence from elastic fibers in adventitia with no detected LS11. Source Courtesy of Prof. K Aizawa, Tokyo Medical University, Tokyo, Japan. 

Pig aortas were stripped of adventitia, snap frozen in liquid nitrogen, crushed into a fine powder, resuspended in 0.05 M Tris buffer (pH 7.5) (1 4, w v) and... 

Blood vessels Intima, media, adventitia Transports blood... 

Bronchiole Mucosa, smooth muscle, adventitia Distributes air... 

The bronchus is a tubular structure that brings air into the alveoli. It is lined with pseudostratified columnar epithelium surrounded by a thin lamina propria containing fine collagen and elastic fibers. A thin layer of smooth muscle surrounds the lamina propria. Glands are found in the submucosa and hyaline cartilage and the pulmonary arteries are found in the outer layer (adventitia). 

Blood vessels include capillaries, arterioles, arteries, and veins. Each of these structures is composed of three layers the intima, media, and adventitia (Figure 3.12). For example, in elastic arteries the wall consists of an intimal layer containing endothelial cells and connective tissue a media containing smooth muscle cells, collagen, and elastic fibers and an adventitia containing collagen fibers, nerves, and blood vessels. In cross-section,... 

Adventitia Fibroblasts Connective tissue Anchors vessel... 

Figure 3.12. Structure of vessels. All vessels contain three layers the intima, media, and adventitia. In large elastic arteries, the intima is found beneath the internal elastic membrane and interfaces with the lumen. The media is found between the internal and external elastic membranes, and the adventitia is found outside the external elastic membrane. The media is less prominent in the other types of vessles.

The arterial wall of animals contains three layers the intima, media, and adventitia however, the wall structure of different vessels varies somewhat. The intima extends from the blood vessel lumen to the internal elastic... 

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