Renal and Urinary System Disorders

Comprehensive practice flashcards covering renal anatomy, physiological functions, diagnostic laboratory studies, urinary tract infections, pyelonephritis, and renal calculi.

Calcitriol

An active hormone produced by the kidneys that regulates calcium homeostasis.

Erythropoietin

A hormone produced by the kidneys that stimulates the bone marrow to produce red blood cells.

Blood Urea Nitrogen (BUN)

A blood test measuring urea, an end-product of protein metabolism excreted by the kidneys.

BUN Reference Range

$$5-25\,mg/dL$$

Cause of Elevated BUN

Dehydration or reduced renal clearance of urea.

Cause of Decreased BUN

Over-hydration, which is a rare clinical finding.

Serum Creatinine

A waste product byproduct of muscle activity and creatinine phosphate that the kidneys filter and remove from the blood.

Serum Creatinine Reference Range

$$0.5-1.2\,mg/dL$$

Renal Cortex

The outer region of the kidney parenchyma containing glomeruli and convoluted tubules.

Renal Medulla

The inner region of the kidney composed of renal pyramids and tubular structures.

Renal Pyramids

Triangular tissues located in the renal medulla that contain tubular segments and nephron collecting ducts.

Renal Columns

Extensions of cortical tissue that project inward between adjacent renal pyramids.

Renal Calyces

Minor and major cup-like cavities in the kidney through which urine flows from the renal papillae into the pelvis.

Renal Pelvis

The funnel-shaped basin of the kidney that collects urine from the major calyces and conveys it into the ureter.

Nephron

The microscopic structural and functional filtering unit of the kidney.

Glomerulus

A tuft of microscopic capillaries within the renal corpuscle where plasma is filtered.

Bowman's Capsule

The double-walled epithelial cup that surrounds the glomerulus to receive initial filtrate.

Proximal Convoluted Tubule

The segment of the renal tubule originating from Bowman's capsule responsible for extensive fluid and solute reabsorption.

Loop of Henle

A U-shaped portion of the renal tubule consisting of descending and ascending limbs that functions in concentrating urine.

Distal Convoluted Tubule

The convoluted portion of the nephron between the loop of Henle and the collecting system that regulates electrolytes.

Collecting Duct

A tubular channel that collects processed fluid from multiple nephrons and drains urine toward the renal calyces.

Afferent Arteriole

The small artery branch that delivers unfiltered blood directly to the glomerulus.

Efferent Arteriole

The small blood vessel that conveys filtered blood away from the glomerular capillaries.

Juxtaglomerular Apparatus

A specialized microscopic complex located near the vascular pole of the glomerulus that assists in blood pressure regulation.

Peritubular Capillaries (Vasa Recta)

The capillary network surrounding the renal tubular network that allows solute exchange and reabsorption.

Urinary Tract Infection (UTI)

The presence and proliferation of microorganisms within the urinary tract causing inflammation.

Escherichia coli

The most common bacterial pathogen responsible for urinary tract infections.

Urethritis

A urinary tract infection and inflammation involving the urethra.

Cystitis

A lower urinary tract infection and inflammation involving the urinary bladder.

Pyelonephritis

An upper urinary tract infection and inflammation involving the renal parenchyma, pelvis, and ureters.

Upper UTI

An infection involving upper urinary tract structures including the kidneys (pyelonephritis) and ureters (ureteritis).

Lower UTI

An infection involving lower urinary tract structures including the bladder (cystitis) and urethra (urethritis).

Urosepsis

A life-threatening systemic spread of bacterial infection originating from the urinary tract.

Uncomplicated UTI

A urinary tract infection isolated strictly to the bladder in an otherwise structurally normal urinary tract.

Complicated UTI

A UTI that occurs in the presence of structural or functional urinary tract abnormalities, or during pregnancy.

Ascending Infection

The most common route of UTI pathogenesis where microorganisms travel upward from the urethra to the bladder and kidneys.

Hematogenous Spread

A descending route of renal infection where organisms reach the kidney via the bloodstream from septicemia or infective endocarditis.

Dysuria

Painful, difficult, or burning urination.

Urinary Urgency

A sudden, compelling, and intense urge to urinate that cannot be easily delayed.

Urinary Frequency

The need to urinate more often than usual without an increase in overall urine output.

Suprapubic Pain

Discomfort or pain located in the lower abdomen directly overlying the bladder, typical of cystitis.

Hematuria

The presence of red blood cells in the urine, giving it a pink, red, or brownish hue.

Atypical Presentation of UTI in Older Adults

The sudden onset of confusion, altered mental status, and general malaise rather than localized dysuria.

Costovertebral Angle (CVA) Tenderness

Pain or tenderness elicited by percussion over the costovertebral angle, indicative of kidney inflammation or pyelonephritis.

CVA Percussion Technique

Placing one hand flat on the client's back over the costovertebral angle and striking it with the ulnar surface of the opposite fist.

Leukocyte Esterase

An enzyme produced by white blood cells that indicates pyuria and active urinary infection when positive on a dipstick test.

Nitrite Dipstick Test

A urine test that turns positive when gram-negative bacteria (such as E. coli) reduce dietary nitrates to nitrites.

Turbid Urine

Cloudy, opaque urine caused by the presence of bacteria, leukocytes, and epithelial debris.

Pyuria

The presence of white blood cells or pus in the urine, typically defined as greater than $5$ WBCs per high-power field.

White Blood Cell (WBC) Casts

Cylindrical aggregates of leukocytes formed within the renal tubules that indicate upper urinary tract (kidney) involvement.

Urine Culture and Sensitivity (C&S)

A microbiological test that identifies the causative microorganism of a UTI and determines effective antibiotic therapies.

Clean-Catch Midstream Specimen

A voided urine sample collected after perineal cleansing and initial voiding to prevent skin and urethral flora contamination.

Bactrim (Sulfamethoxazole/Trimethoprim)

A combined antimicrobial medication used as first-line empirical therapy for uncomplicated UTIs.

Standard Bactrim Formulation

A tablet formulation containing $400\,mg$ sulfamethoxazole and $80\,mg$ trimethoprim.

Empirical Treatment for Uncomplicated Cystitis

A $3$-day regimen of trimethoprim-sulfamethoxazole (Bactrim) initiated based on clinical symptoms and urinalysis.

Phenazopyridine (Pyridium)

An azo dye urinary analgesic that provides topical pain relief to the urinary tract mucosa to treat burning and urgency.

Phenazopyridine Urine Discoloration

A harmless, expected pharmacological effect where the patient's urine turns a distinctive red or bright orange.

Side Effects of Phenazopyridine

Headache and skin rash; requires medical notification if symptoms do not subside.

Ciprofloxacin

A broad-spectrum fluoroquinolone antibiotic formulated for IV infusion ($200\,mg/100\,mL$) or oral use in complicated UTIs and pyelonephritis.

Catheter-Associated Urinary Tract Infection (CAUTI)

A healthcare-associated urinary tract infection occurring in a patient with an indwelling urinary catheter.

Primary CAUTI Prevention Measures

Avoiding unnecessary catheterizations, early removal of indwelling lines, hand hygiene, and strict aseptic catheter care.

SureStep Foley Care Protocol

A post-insertion catheter cleansing protocol using dedicated wipes per step: Step 1 for Foley tubing, Step 2 for labia/glans, Step 3 for labia/shaft, and Steps 4 & 5 for groin.

Front-to-Back Wiping

A perineal cleansing technique for females that prevents the transfer of fecal bacteria from the perianal area to the urethra.

Fluid Intake Goal for Cystitis Prevention

Drinking $8\text{ to }10\text{ glasses}$ of fluid per day to maintain frequent urinary tract flushing.

Post-Coital Voiding

Urinating immediately after sexual intercourse to mechanically eliminate microorganisms introduced into the urethra.

Perineal Irritants to Avoid

Bubble baths, vaginal deodorants, and scented toilet paper that cause local mucosal irritation.

Vesicoureteral Reflux (VUR)

The retrograde backward flow of urine from the bladder into the ureters and renal pelvis, predisposing to recurrent pyelonephritis.

Urinary Stasis

Stagnant or incomplete evacuation of urine within the urinary tract that fosters bacterial overgrowth and stone formation.

Female UTI Predisposition

A shorter anatomical urethra and its close physical proximity to the rectum and anus.

FF Chills DUF

A clinical mnemonic for pyelonephritis: Flank pain, Fever, chills, Dysuria, Urgency, and Frequency.

Acute Pyelonephritis

An active, sudden bacterial infection of the kidney causing enlarged parenchyma, microabscesses, fever, chills, and flank pain.

Chronic Pyelonephritis

A recurring or persistent kidney infection leading to scarring, cortical atrophy, fibrous contraction, and loss of renal function.

Preferred Imaging for Pyelonephritis

An abdominal and pelvic CT scan to evaluate renal swelling, abscesses, and urinary obstruction.

Pyelonephritis: Acute vs. Chronic Morphology

Acute pyelonephritis features swollen tissue with small pus spots/abscesses, whereas chronic pyelonephritis exhibits a contracted, shrunken, fibrotic, bumpy kidney.

Gram-Negative Pyelonephritis Pathogens

Escherichia coli, Proteus, Klebsiella, and Enterobacter species.

Renal Calculi

Hard mineral or salt crystal deposits formed inside the kidneys, also known as nephrolithiasis or kidney stones.

Renal Colic

Severe, agonizing flank pain caused by the passage and spasm of a calculus through the ureter, often radiating to the groin or testicles.

Intrinsic Ureteral Obstruction

Urinary tract blockage originating from inside the ureteral lumen, such as calculi, tumors, blood clots, or inflammation.

Extrinsic Ureteral Obstruction

Urinary tract blockage caused by external compression on the ureter, such as pregnancy, cervical tumors, or strictures.

Ureteropelvic Junction (UPJ) Obstruction

A blockage at the junction connecting the renal pelvis to the upper ureter.

Ureterovesical Junction (UVJ)

The narrow anatomical entry point where the ureter connects to the urinary bladder, a common site for stone lodgment.

Calcium Oxalate Stones

The most common form of kidney stone, associated with dehydration, high oxalate intake, and obesity.

Calcium Phosphate Stones

Renal calculi formed in alkaline urine associated with high mineral excretion of calcium, phosphate, and uric acid.

Uric Acid Stones

Kidney stones formed in persistently acidic urine in individuals with elevated serum or urinary uric acid levels.

Struvite Stones

Magnesium ammonium phosphate stones (often staghorn calculi) formed secondary to chronic urinary tract infections by urease-producing bacteria.

Cystine Stones

Rare hereditary calculi resulting from an autosomal recessive defect in renal tubular amino acid reabsorption.

Kidney Stone Types

The four distinct mineral types of urinary stones: calcium stone, uric acid stone, struvite stone, and cystine stone.

Noncontrast Helical (Spiral) CT

The gold-standard diagnostic imaging modality for quickly confirming the size, shape, and anatomical location of urinary calculi without dye.

KUB (Kidneys, Ureters, Bladder) X-Ray

A plain abdominal radiograph used to identify the presence, size, shape, and position of radiopaque urinary stones.

Intravenous Pyelogram (IVP)

An intravenous radiographic contrast study used to delineate renal structures and detect urinary obstruction.

24-Hour Urine Collection for Calculi

A quantitative timed urine collection used to evaluate the metabolic output of calcium, oxalate, uric acid, and citrate.

Stone Composition Analysis

Laboratory examination of a retrieved or passed calculus to identify its mineral components and guide preventive therapy.

Extracorporeal Shock Wave Lithotripsy (ESWL)

A noninvasive medical procedure that shatters kidney calculi into small, passable sand-like fragments using focused shock waves.

Flomax (Tamsulosin) in Calculi Management

An alpha-1 adrenergic antagonist administered to relax ureteral smooth muscle and promote spontaneous stone passage.

Post-Lithotripsy Urine Straining

A critical nursing intervention requiring all voided urine to be filtered through gauze or a stone strainer to recover fragments for analysis.

Post-Lithotripsy Fluid Intake Goal

Maintaining a fluid intake of approximately $3\,L/day$ to facilitate fragment expulsion.

Post-Lithotripsy Hematuria

An expected finding of blood in the urine following shock wave treatment that should resolve gradually.

Dietary Oxalate Restriction

A dietary modification strategy for calcium oxalate stone formers that eliminates foods rich in oxalates to reduce urinary excretion.

High-Oxalate Foods to Avoid

Foods including spinach, rhubarb, beets, potatoes and yams, seeds and nuts, wheat bran, legumes, and chocolate.

Low-Oxalate Foods to Enjoy

Foods including broccoli, iceberg lettuce, bok choy, peppers, low-fat dairy, bananas, cantaloupes, and papaya.