WGU D115 OA 2026 Exam Preparation Guide: High-Yield Concepts and Practice Questions

Which part of the colon is primarily affected in ulcerative colitis? A) Entire digestive tract B) Sigmoid colon and rectum C) Jejunum and ileum D) Stomach and duodenum Rationale: Ulcerative colitis is limited to the colon, primarily the sigmoid colon and rectum. Crohn’s disease, in contrast, can affect any part of the GI tract from mouth to anus. Options A, C, and D are more characteristic of Crohn’s or other GI conditions. Which type of inflammation is characteristic of Crohn’s disease? A) Continuous mucosal inflammation B) Transmural inflammation with skipped lesions C) Limited to the rectum only D) Superficial inflammation without granulomas Rationale: Crohn’s disease causes transmural inflammation and often shows skipped lesions. Ulcerative colitis is continuous and limited to the mucosa. Option D describes minimal change patterns not seen in Crohn’s. A patient with a recent streptococcal infection is most likely to develop which type of kidney syndrome? A) Nephrotic syndrome B) Nephritic syndrome C) Minimal change disease D) Chronic kidney disease Rationale: Nephritic syndrome often follows post-streptococcal infections and presents with hematuria, hypertension, and reduced GFR. Nephrotic syndrome (A) is associated with heavy proteinuria, not recent strep. Options C and D are chronic or unrelated. Which of the following defines a struvite kidney stone? A) Small, round, and asymptomatic B) Grows large and branches into a staghorn configuration C) Caused by hypercalcemia D) Only occurs in men Rationale: Struvite stones are associated with UTIs, especially in women, and can grow into large staghorn formations. Options A and C describe other types of stones (e.g., calcium oxalate). D is incorrect because struvite stones are more common in women. What is the primary function of stomach acid? A) Neutralizes food B) Converts pepsinogen into pepsin C) Absorbs nutrients D) Stimulates colon motility Rationale: Stomach acid (HCl) activates pepsinogen into pepsin for protein digestion. It also acts as a bactericide. Options A, C, and D are incorrect functions of HCl. Which is true regarding colorectal cancer? A) Most arise from inflammatory bowel disease B) Most arise from hyperplastic polyps C) Most arise from adenomatous polyps D) It never arises from polyps Rationale: Adenomatous polyps are precancerous lesions that commonly progress to colorectal cancer. Options A and B are incorrect associations; D is false. In the distal tubule, which cells reabsorb sodium and water and secrete potassium? A) Macula densa B) Juxtaglomerular cells C) Principal cells D) Intercalated cells Rationale: Principal cells in the distal tubule manage sodium and water reabsorption and potassium secretion. Intercalated cells regulate acid-base balance, while A and B have other functions. Which muscle lies between the two openings of the ureter and urethra? A) Detrusor B) External sphincter C) Trigone D) Internal sphincter Rationale: The trigone is a triangular smooth muscle region between ureteric and urethral openings. Detrusor contracts the bladder, and sphincters control urine outflow. A posterior pituitary tumor producing excess ADH leads to elevated blood volume and BP. Which hormone would also be increased? A) Renin B) Aldosterone C) Cortisol D) Atrial natriuretic peptide (ANP) Rationale: ANP is released in response to increased blood volume to promote natriuresis. Options A–C do not directly respond to volume expansion in this context. Which finding is normal in a urinalysis? A) Protein 200 mg/dL B) Glucose present C) Specific gravity 1.016–1.022 D) Ketones present Rationale: Normal urine has specific gravity between 1.016 and 1.022. Proteinuria, glucosuria, or ketonuria indicate pathology. Which term refers to the filtration of plasma per unit of time in the glomeruli? A) Tubular reabsorption B) Renal plasma flow C) Glomerular filtration rate (GFR) D) Creatinine clearance Rationale: GFR quantifies plasma filtration by the glomeruli per time unit. Tubular reabsorption is a different process, and renal plasma flow measures overall renal perfusion. Which substance controls final urine concentration? A) Aldosterone B) Renin C) ADH D) ANP Rationale: ADH regulates water reabsorption in collecting ducts, concentrating urine. Aldosterone affects sodium reabsorption, while renin and ANP have indirect effects. Where do the renal arteries emerge from? A) Third branches of the abdominal aorta B) Celiac trunk C) Fifth branches of the abdominal aorta D) Superior mesenteric artery Rationale: Renal arteries branch directly from the abdominal aorta, typically around the level of L1–L2, which corresponds to the fifth branch. Other options supply different organs. Movement of fluids and solutes from the tubular lumen to the peritubular capillaries is called: A) Filtration B) Secretion C) Tubular reabsorption D) Excretion Rationale: Tubular reabsorption returns substances from the nephron to the blood. Filtration is the opposite, secretion adds substances to the nephron, and excretion is removal via urine. Which is NOT a complication of horseshoe kidney? A) Hydronephrosis B) Kidney stones C) Hypospadias D) Urinary tract infections Rationale: Hypospadias is a urethral malformation, unrelated to horseshoe kidney. Options A, B, and D are common complications due to anatomical obstruction. Which term describes a urethral opening on the dorsal surface of the penis? A) Hypospadias B) Epispadias C) Phimosis D) Epispadias Rationale: Epispadias is dorsal urethral opening; hypospadias is ventral. Phimosis is prepuce narrowing. Which term describes abnormal differentiation of renal tissues? A) Renal agenesis B) Renal hypoplasia C) Renal dysplasia D) Polycystic kidney Rationale: Renal dysplasia refers to abnormal tissue differentiation. Hypoplasia is underdeveloped but normal tissue, agenesis is absent kidney, and polycystic kidney is cystic disease. Which statement is true regarding acute post-streptococcal glomerulonephritis? A) Caused by viral infection B) Exact mechanism of immune complex formation is unknown C) Always progresses to CKD D) Only affects children under 5 Rationale: The exact immune mechanisms are not fully understood. Options A, C, and D are incorrect; it affects a wider age range and does not always cause CKD. Which renal manifestation is associated with wide-set eyes, “parrot beak” nose, low-set ears, and receding chin? A) Renal dysplasia B) Nephrotic syndrome C) Potter syndrome D) Wilms tumor Rationale: Potter syndrome arises from renal agenesis leading to oligohydramnios and characteristic facial features. Other options do not present with these facial findings. A patient presents with hematuria, mild proteinuria, abdominal pain, and skin lesions. Which disease is likely? A) IgA nephropathy B) Henoch-Schonlein purpura C) Minimal change disease D) Acute tubular necrosis Rationale: HSP presents with palpable purpura, hematuria, and abdominal pain. IgA nephropathy may cause hematuria but without systemic symptoms; minimal change disease causes nephrotic syndrome without skin lesions. What is the cause of minimal change nephropathy? A) Immune complex deposition B) Fusion of glomerular foot processes C) Granuloma formation D) Tubular obstruction Rationale: Minimal change disease shows podocyte foot process effacement, causing proteinuria. Immune complexes and granulomas are not features. A child with enlarged kidneys, fever, and abdominal pain likely has: A) Chronic kidney disease B) Acute pyelonephritis C) Minimal change disease D) Nephrolithiasis Rationale: Fever, chills, abdominal pain, and kidney enlargement indicate bacterial infection— pyelonephritis. CKD and minimal change are chronic; stones do not cause systemic infection. Which electrolyte imbalances are seen in chronic renal failure? A) Hypernatremia, hypokalemia, hypercalcemia B) Hyponatremia, hypophosphatemia, alkalosis C) Hypernatremia, hypocalcemia, hyperkalemia, hyperphosphatemia, bicarbonate deficiency D) Hypokalemia, hypocalcemia, hypernatremia Rationale: CKD causes sodium retention, potassium and phosphate accumulation, hypocalcemia, and metabolic acidosis. Other options misrepresent common CKD imbalances. A 78-year-old patient with distended bladder, BUN 88 mg/dL, creatinine 2.8 mg/dL most likely has: A) Prerenal azotemia B) Postrenal azotemia C) Intrinsic renal failure D) Minimal change disease Rationale: Postrenal azotemia is due to obstruction, which fits distended bladder. Prerenal azotemia is due to low perfusion; intrinsic damage is within the kidney. A 68-year-old woman with heart failure, tachycardia, S3, low BP, BUN 58 mg/dL, creatinine 2.4 mg/dL most likely has: A) Postrenal azotemia B) Intrinsic renal failure C) Prerenal azotemia D) Chronic kidney disease Rationale: Prerenal azotemia results from decreased perfusion, often due to heart failure. Postrenal requires obstruction. CKD is chronic, and intrinsic damage is usually acute tubular necrosis or glomerulonephritis. Which patient is most likely to require dialysis due to chronic kidney disease? A) 64-year-old with GFR 55 mL/min B) 70-year-old with GFR 45 mL/min C) 64-year-old with type 2 diabetes and GFR 28 mL/min D) 60-year-old with mild proteinuria Rationale: Dialysis is considered when GFR <30 mL/min with symptoms or comorbidities. Options A, B, D have higher GFRs not warranting dialysis. What is the primary mechanism of damage in diabetic nephropathy? A) Podocyte apoptosis B) Elevated transforming growth factor-beta causing inflammation C) Bacterial infection D) Hyperfiltration alone Rationale: TGF-β mediates fibrosis and inflammation in diabetic nephropathy. Hyperfiltration contributes but is secondary. Options A and C are not primary mechanisms. A patient with acute blood loss and hypotension controls renal blood flow by: A) Increased ANP B) Decreased renin C) Increased sympathetic vasoconstrictor activity D) Tubuloglomerular feedback Rationale: Sympathetic activation constricts renal arteries to maintain perfusion. ANP decreases volume, renin would increase, and tubuloglomerular feedback adjusts GFR locally, not systemic perfusion. In a septic patient with rising serum creatinine, which is most likely? A) Postrenal damage B) Chronic kidney disease C) Prerenal kidney damage D) Minimal change disease Rationale: Sepsis causes hypotension and decreased perfusion, leading to prerenal injury. Postrenal requires obstruction; minimal change disease is unrelated. Which patient is at greatest risk for nephrolithiasis? A) Female, underweight, no comorbidities B) Male, DM, obesity C) Elderly female, normal weight D) Child with UTIs Rationale: Kidney stones are more common in males, diabetics, and obese patients. Options A, C, D have lower risk. A patient with fracture, high serum phosphate, and eGFR 18 mL/min likely has: A) Acute kidney injury B) Hyperparathyroidism C) CKD mineral and bone disorder (CKD-MBD) D) Osteoporosis Rationale: CKD-MBD arises from phosphate retention and secondary bone metabolism changes. Acute kidney injury is sudden; osteoporosis does not involve renal phosphate retention. How does hypertension cause nephropathy? A) Direct infection B) Immune complex deposition C) Hyperfiltration causing slow nephron deterioration D) Trauma Rationale: Chronic high BP increases glomerular pressure, slowly damaging nephrons. Options A, B, D are unrelated. A 35-year-old man with edema, high BP, dark foamy urine, suspected acute glomerulonephritis would NOT show: A) Hematuria B) Proteinuria C) Elevated glucose D) Hypertension Rationale: Glomerulonephritis causes hematuria, proteinuria, and hypertension but does not elevate glucose. Which sign is most likely in a healthy 27-year-old woman with uncomplicated lower UTI? A) Hematuria B) Urinary frequency C) Delirium D) Weakness Rationale: Lower UTI commonly presents with urinary frequency and urgency. Hematuria and systemic signs are less common. In elderly women, uncomplicated UTI is more likely to present with: A) Dysuria B) Hematuria C) New-onset urinary incontinence, delirium, weakness D) Fever only Rationale: Elderly often have atypical UTI presentations like incontinence, delirium, or general weakness. Hematuria is not typical. The most likely causative organism for community-acquired UTI in reproductive-age women is: A) Staphylococcus aureus B) Pseudomonas aeruginosa C) E. coli from colon contamination D) Klebsiella Rationale: E. coli is the most common pathogen due to fecal contamination. Other organisms are less common in community-acquired infections.