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The human urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, control levels of electrolytes and metabolites , and regulate blood pH .
The ureters can be affected by a number of diseases, including urinary tract infections and kidney stone. Stenosis is when a ureter is narrowed, due to for example chronic inflammation. Congenital abnormalities that affect the ureters can include the development of two ureters on the same side or abnormally placed ureters. Additionally, reflux ...
In the human adult, the ureters are usually 25–30 cm (10–12 in) long. In humans, the ureters arise from the renal pelvis on the medial aspect of each kidney before descending towards the bladder on the front of the psoas major muscle. The ureters cross the pelvic brim near the bifurcation of the iliac arteries (which they run over).
Metanephros is the most complex form of kidney. [44] Each metanephric kidney is characterized by a large number of nephrons and a highly branched system of collecting tubules and ducts, [28] that open into the ureter. [48] Such branching in the metanephros is unique in relation to the pronephros and mesonephros. [44]
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 mesoderm around the tubules becomes condensed to form the connective tissue of the kidney. The ureter opens at first into the hind-end of the Wolffian duct; after the sixth week it separates from the Wolffian duct, and opens independently into the part of the cloaca which ultimately becomes the urinary bladder.
[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 ]
Facet cells (also known as umbrella cells, [1] capping cells, superficial urotheliocytes) are a type of cells located in the renal pelvis, the ureters, and the urethra. Umbrella cells form the outermost layer of the urothelium, which is a special type of epithelium found in the renal pelvis, the ureters, and the urethra.