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Staghorn Calculi
Kidney stone disease (known as nephrolithiasis, renal calculus disease, or urolithiasis) is a crystallopathy and occurs when there are too many minerals in the urine and not enough liquid or hydration. This imbalance causes tiny pieces of crystal to aggregate and form hard masses, or calculi (stones) in the upper urinary tract. Because renal calculi typically form in the kidney, if small enough, they are able to leave the urinary tract via the urine stream. A small calculus may pass without causing symptoms. However, if a stone grows to more than , it can cause blockage of the ureter, resulting in extremely sharp and severe pain (renal colic) in the lower back that often radiates downward to the groin. A calculus may also result in blood in the urine, vomiting (due to severe pain), or painful urination. About half of all people who have had a kidney stone are likely to develop another within ten years. ''Renal'' is Latin for "kidney", while "nephro" is the Greek equivalent. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the centre of the circle and whose endpoints lie on the circle. It can also be defined as the longest Chord (geometry), chord of the circle. Both definitions are also valid for the diameter of a sphere. In more modern usage, the length d of a diameter is also called the diameter. In this sense one speaks of diameter rather than diameter (which refers to the line segment itself), because all diameters of a circle or sphere have the same length, this being twice the radius r. :d = 2r \qquad\text\qquad r = \frac. The word "diameter" is derived from (), "diameter of a circle", from (), "across, through" and (), "measure". It is often abbreviated \text, \text, d, or \varnothing. Constructions With straightedge and compass, a diameter of a given circle can be constructed as the perpendicular bisector of an arbitrary chord. Drawing two diameters in this way can be used to locate the center of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
