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An eye web is a noncancerous, triangular growth that may occur on one or both eyes. It's more common in people who spend a lot of time in the sun, such as those who work outdoors. The painless growth may be slightly raised and contain obvious blood vessels. It may cause irritation and possibly affect vision. Treatment usually isn't necessary. Eyedrops or surgery may help in severe cases.
Normal Heart Sounds With the aid of a stethoscope you can hear the characteristic sounds of the normal heartbeat, typically described as a "lub-dub." These sounds are produced by the closure of the heart valves. The first heart sound or "lub" results from closure of the tricuspid and mitral valves. It is a rather low-pitched and a relatively long sound which, as indicated in, represents the beginning of ventricular systole. The second heart sound, or "dub," marks the beginning of ventricular diastole. It is produced by closure of the aortic and pulmonary (pulmonic) semilunar vanes when the intraventricular pressure begins to fall. This "dub" sound is typically heard as a sharp snap because the semilunar valves tend to close much more rapidly than the AV valves. Because diastole occupies more time than systole, a brief pause occurs after the second heart sound when the heart is beating at a normal rate. Therefore, the pattern that one hears is one of: "lub-dub" pause, "lub-dub" pause, and so on. Sometimes, especially in young normal individuals, a third heart sound can be heard. This sound is produced by the very rapid influx of blood into the partially filled ventricle. It is typically very faint and as such difficult to hear.
The colonoscope is slowly withdrawn during this screening colonoscopy down from the transverse colon, back around the splenic flexure, and down the descending colon, and reveals this finding a colonic diverticula. Diverticulosis is a common, acquired, age-related occurrence affecting over 50% of the... western adult population over the age of 50. It is seen rarely in Africa and Asia where the dietary fiber content is traditionally higher. Thus most investigators feel that low fiber diets are related to the development of this condition. Ironically, colonic diverticula are not true diverticula but rather pseudodiverticula in that the sac includes layers of the mucosa and submucosa that push through rather than include the outer muscular layer. As with the small bowel the colon has an inner circular muscular layer, but the outer longitudinal layer is composed of three bands of muscle that run the length of the colon known as teniae. Diverticula occur in rows between the mesenteric and two antimesenteric teniae where the colonic wall is further weakened by the defect caused by the perforating vasa recti artery which supplies the colonic mucosa. Occasionally, the anatomic propensity of diverticula to form in rows is quite apparent as seen when this clip is replayed in slow motion. Most often, however, the arrangement of the diverticula appears random due to the angulation of the bowel and thickening of the semi lunar folds. The conditions that cause these pulsion diverticula are not know with certainty but may include high intrahaustral pressures, muscular hypertrophy, and age related alterations in collagen cross linking. Diverticula can bleed or can abscess and perforate. The incidence of diverticulitis or diverticular bleeding is in the range of 1:1,000 patients with diverticulosis.