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Duplicated ureter or duplex collecting system is a congenital condition in which the ureteric bud, the embryological origin of the ureter, splits (or arises twice), resulting in two ureters draining a single kidney. It is the most common renal abnormality, occurring in approximately 1% of the population.
The signs and symptoms of hydronephrosis depend upon whether the obstruction is acute or chronic, partial or complete, unilateral or bilateral.Hydronephrosis that occurs acutely with sudden onset (as caused by a kidney stone) can cause intense pain in the flank area (between the hips and ribs) known as a renal colic.
The renal calyces (sg. calyx) are conduits in the kidney through which urine passes. The minor calyces form a cup-shaped drain around the apex of the renal pyramids.Urine formed in the kidney passes through a renal papilla at the apex into the minor calyx; four or five minor calyces converge to form a major calyx through which urine passes into the renal pelvis (which in turn drains urine out ...
The unipapillary kidney with a single renal pyramid is the simplest type of kidney in mammals, from which the more structurally complex kidneys are believed to have evolved. [17] [6] [18] Differences in kidney structure are the result of adaptations during evolution to variations in body mass and habitats (in particular, aridity) between species.
The kidney is surrounded by tough fibrous tissue, the renal capsule, which is itself surrounded by perirenal fat, renal fascia, and pararenal fat. The anterior (front) surface of these tissues is the peritoneum, while the posterior (rear) surface is the transversalis fascia. The superior pole of the right kidney is adjacent to the liver.
The urinary system refers to the structures that produce and transport urine to the point of excretion. In the human urinary system there are two kidneys that are located between the dorsal body wall and parietal peritoneum on both the left and right sides. The formation of urine begins within the functional unit of the kidney, the nephrons.
[citation needed] A large "staghorn" kidney stone may block all or part of the renal pelvis. The size of the renal pelvis plays a major role in the grading of hydronephrosis . Normally, the anteroposterior diameter of the renal pelvis is less than 4 mm in fetuses up to 32 weeks of gestational age and 7 mm afterwards. [ 2 ]
Changes in renin ultimately alter the output of this system, principally the hormones angiotensin II and aldosterone. Each hormone acts via multiple mechanisms, but both increase the kidney's absorption of sodium chloride, thereby expanding the extracellular fluid compartment and raising blood pressure. When renin levels are elevated, the ...