pyelo

Pyelo is a combining form used in medical terminology to denote the renal pelvis, the funnel-shaped proximal part of the ureter within the kidney. The term derives from Greek pyelos meaning pelvis and is used to form terms related to the pelvicalyceal system of the kidney. It is distinct from pelv- which can refer more broadly to pelvic structures.

Common terms incorporating pyelo include pyelonephritis, which is an infection of the kidney that typically involves the renal pelvis and surrounding tissue; pyelitis, inflammation confined to the renal pelvis; pyelogram, a radiographic image of the renal pelvis; and intravenous pyelography (IVP), an imaging study once widely used to evaluate the urinary tract. Surgical and surgical-tract terms include pyeloplasty (reconstruction of the renal pelvis and ureteropelvic junction) and pyelolithotomy (removal of stones from the renal pelvis). The adjective form pyelo- appears in terms such as pyelocaliceal, relating to the renal pelvis and calyces, or combined in phrases like pyeloureterostomy.

Anatomically, the renal pelvis collects urine from the calyces and funnels it into the ureter at the renal hilum. It forms part of the pelvicaliceal system, which collects urine within the kidney before drainage.

Clinically, conditions affecting the renal pelvis can arise from infection, stone obstruction, or inflammatory processes. Pyelonephritis is typically an ascending infection that may cause flank pain, fever, and urinary symptoms. Obstruction or stones can lead to hydronephrosis or pyonephrosis. Diagnosis relies on imaging such as ultrasound or CT urography, with historical use of IVP; treatment ranges from antibiotics to urological procedures to relieve obstruction or remove stones.

Usage of pyelo is specialized to nephrology and urology and appears as a root in terms describing the renal pelvis.

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