NURS 4435 Unit 10: Renal System and Urinary Tract Focused Review

Vocabulary practice cards focusing on key pathophysiological concepts, diagnostic criteria, and clinical features of the renal system and urinary tract.

Nephron

The working unit of the kidney that begins at Bowman's capsule, where filtering starts, and continues as a long tubule.

Ureteropelvic Junction (UPJ)

The anatomical site where the ureters begin before moving urine downward by peristalsis.

Three-Layer Filtration Membrane

The filtration barrier in the glomerulus consisting of fenestrated endothelium (keeps blood cells out), basement membrane (blocks larger proteins), and podocytes (the outer cells).

Glomerular Filtration Rate (GFR)

The rate of fluid filtration across the glomerulus, with a typical value of $120\text{ to }125\,\text{mL/min}$, regulated by the myogenic mechanism and tubuloglomerular feedback.

Proximal Convoluted Tubule (PCT)

The tubule segment where reabsorption begins, recovering all filtered glucose and amino acids as well as about $65\%$ of filtered sodium and water.

Renal Clearance

A measurement of how much blood the kidneys clear of a specific waste product in a given period of time.

Antidiuretic Hormone (ADH)

A hormone released by the pituitary when hypothalamic osmoreceptors detect concentrated blood or low volume; it causes collecting ducts to reabsorb more water, raising blood volume and blood pressure.

Renin-Angiotensin-Aldosterone System (RAAS)

A neurohormonal pathway triggered when juxtaglomerular cells release renin in response to low blood pressure, low volume, or low sodium, leading to the formation of angiotensin II by ACE.

Aldosterone

A hormone secreted by the adrenal glands that promotes sodium reabsorption (followed by water) and potassium excretion in the distal convoluted tubule and collecting duct.

Calcitriol

The active form of vitamin D converted by the kidneys from calcifediol produced in the liver; failure of this conversion in CKD results in low calcium and high phosphate.

Erythropoietin (EPO)

A hormone produced by the kidneys that stimulates red blood cell production; deficiency in chronic kidney disease leads to anemia.

Hypertrophy vs. Hyperplasia

Adaptive cellular changes where hypertrophy indicates that existing cells increase in size, whereas hyperplasia indicates an increase in the number of cells.

Chronic Kidney Disease (CKD)

Kidney damage or an eGFR below $60\,\text{mL/min}/1.73\,\text{m}^2$ persisting for more than $3\,\text{months}$, commonly caused by diabetes and hypertension.

Acute Kidney Injury (AKI)

A sudden loss of kidney function resulting from illness or injury, categorized into prerenal, intrinsic, and postrenal etiologies.

Prerenal AKI

A form of acute kidney injury caused by reduced blood flow to the kidneys without direct structural damage to the kidney tissue.

Intrinsic AKI

Acute kidney injury resulting from direct damage to renal tissue, caused by toxins, inflammation, sepsis, acute tubular necrosis, glomerulonephritis, or interstitial nephritis.

Postrenal AKI

Acute kidney injury caused by mechanical obstruction of urine flow—such as from stones, tumors, retroperitoneal fibrosis, or an enlarged prostate—which increases retrograde pressure in the kidney.

AKI Diagnostic Criteria

Defined by an increase in serum creatinine of at least $0.3\,\text{mg/dL}$ within $48\,\text{hours}$, an increase of $1.5\,\text{times}$ baseline within $7\,\text{days}$, or urine output under $0.5\,\text{mL/kg/hr}$ for at least $6\,\text{hours}$.

Nephritic Syndrome

Glomerular inflammation often following an infection, characteristically presenting with hematuria (blood in the urine), red blood cell casts, and mild proteinuria.

Nephrotic Syndrome

A condition resulting from podocyte damage that causes large quantities of protein to leak into the urine, producing severe hypoalbuminemia and edema.

Renal Osteodystrophy

A bone disease complication seen in chronic kidney disease resulting from abnormal mineral metabolism, including low calcitriol, hypocalcemia, and hyperphosphatemia.

Nephrolithiasis

The formation of kidney stones when urine becomes supersaturated and minerals precipitate out of solution; most commonly composed of calcium oxalate and calcium phosphate.

Struvite Stones

A specific type of kidney stone associated with ongoing urinary tract infections that requires antibiotics and complete surgical or procedural removal.

Hydronephrosis

Distension and swelling of the renal pelvis and calyces caused by prolonged urinary tract obstruction and elevated retrograde pressure.

Costovertebral Angle (CVA) Tenderness

The key physical examination finding of tenderness over the lower back/kidney region that distinguishes pyelonephritis from lower urinary tract infections like cystitis.

Pyelonephritis Classic Triad

The hallmark clinical presentation of upper urinary tract infection consisting of fever, one-sided flank pain, and nausea or vomiting.

Fimbriae and Pili

Bacterial surface appendages utilized by Escherichia coli to adhere to the bladder lining, resisting flushing by urine flow to colonize and multiply.

Phenazopyridine

A urinary analgesic that provides symptomatic relief of burning and pain during urination but does not treat the underlying bacterial infection.

Painless Gross Hematuria

The most common clinical presenting sign of bladder cancer, which may be intermittent and requires prompt evaluation.

Urothelial Carcinoma

The primary histological type representing more than $90\%$ of all diagnosed bladder cancers.

Transurethral Resection of Bladder Tumor (TURBT)

A surgical procedure used for the definitive biopsy, staging, and initial removal of non-muscle-invasive bladder cancer.

Bacillus Calmette-Guérin (BCG)

An intravesical immunotherapy agent administered into the bladder to treat higher-risk non-muscle-invasive bladder cancer and prevent recurrence.