NR-283 Pathophysiology - Set 4 - Part 3

Correct Answer: Prolonged hypoperfusion has progressed to tubular necrosis

Sustained low perfusion starves the metabolically busy proximal tubule until its cells die. Once necrosis is established the kidney no longer responds to volume, which is the line separating reversible prerenal injury from intrinsic damage. Option b is incorrect because a stone blocking one ureter leaves the other kidney draining freely, so output rarely collapses. Colicky flank pain and hematuria would also dominate the picture, and neither is described. Option c is incorrect because glomerular inflammation develops over days after an infection or in autoimmune disease, not during an operation. Its hallmarks are red cell casts, proteinuria and hypertension rather than surgical hypotension. Option d is incorrect because blaming bolus size ignores what the first client demonstrated with an identical volume. When tubular cells have already died, no amount of fluid will restore urine flow.

Correct Answer: Rising pressure behind a stone lodged in the ureter

Urine keeps forming above the obstructing stone, so intraluminal pressure climbs and the ureter and renal capsule distend while prostaglandin driven smooth muscle spasm adds to it. Pain shifts toward the groin as the stone descends. Option a is incorrect because scratching of the mucosa is a common misconception about renal colic. Stones do cause bleeding into the urine, but the agony comes from obstruction and distension rather than surface trauma. Option b is incorrect because bladder inflammation produces suprapubic pressure with burning, urgency and frequency. Cystitis pain stays low in the pelvis and does not sweep from the flank down into the genital area. Option c is incorrect because enlarging cysts stretch the capsule slowly, giving a dull constant ache with palpable kidneys. Polycystic disease also brings early hypertension, and its discomfort never waxes and wanes in colicky waves.

Correct Answer: Autodigestion of the pancreas by activated trypsin

A stone lodged at the ampulla raises ductal pressure and triggers trypsinogen activation inside the acinar cells. Trypsin then unleashes the remaining enzymes, and the gland digests itself and the surrounding fat. Option a is incorrect because gastric contents entering the peritoneum follow a perforated ulcer, producing sudden rigidity, silence and free air under the diaphragm. Positional relief by leaning forward does not belong to that event. Option b is incorrect because a gangrenous gallbladder causes right upper quadrant pain radiating to the shoulder blade with a positive Murphy sign. Radiation straight to the back with forward relief marks the pancreas. Option d is incorrect because simple ductal stretching yields intermittent biliary colic that resolves once the stone falls back. Pain lasting for hours with unrelenting vomiting signals that enzymes have already escaped their granules.

Correct Answer: The collecting duct cannot respond to vasopressin

Failure to concentrate urine after synthetic hormone is given proves the hormone is present but useless. Lithium damages the collecting duct response, so this is the nephrogenic form, a receptor and post receptor problem rather than a supply problem. Option b is incorrect because a client short of the hormone concentrates urine sharply once it is supplied. The flat osmolality response rules out simple deficiency and shifts attention downstream to the kidney. Option c is incorrect because injury to the storage and release site produces the central form, which also improves dramatically with replacement. Nothing in this history involves head injury or neurosurgery, and the drug exposure points elsewhere. Option d is incorrect because habitual overdrinking dilutes the blood and drives serum sodium low or low normal, and water restriction alone corrects the polyuria. Lithium exposure with an unresponsive kidney makes that explanation unlikely.

Correct Answer: Insulin binds its receptor but intracellular reactions are diminished

Insulin resistance means decreased tissue sensitivity. The hormone still attaches to its surface receptor, but the reactions inside the cell are blunted, so glucose uptake lags and the liver keeps releasing glucose. Option a is incorrect because antibodies in diabetes target islet tissue rather than the hormone itself, and that pattern belongs to the type one process. Destroying insulin would leave the measured level low, not high. Option c is incorrect because total loss of beta cells would abolish endogenous insulin, giving an undetectable level and a ketosis prone course. This client still secretes generously, which rules that picture out. Option d is incorrect because rapid renal clearance would lower the measured concentration, yet this level runs high. Reduced kidney function actually prolongs insulin action and tends to cause hypoglycemia rather than sustained hyperglycemia.

Correct Answer: Residual insulin still restrains lipolysis and ketone production

Type two diabetes leaves enough endogenous insulin to block fat breakdown and the ketogenesis that follows, even when the amount is too small to control glucose. Hyperosmolar hyperglycemic state develops instead. Option a is incorrect because renal excretion never keeps pace with the ketoacid load once fat breakdown runs unchecked. Severe dehydration in this client reduces filtration, which would let any ketones accumulate faster. Option b is incorrect because water loss does not switch off hepatic ketogenesis. Clients in ketoacidosis are profoundly dry and still generate large amounts of acetoacetate and beta hydroxybutyrate throughout the illness. Option c is incorrect because glucagon, cortisol and catecholamines rise sharply during any hyperglycemic crisis, driving hepatic glucose output higher. Their suppression would lower glucose instead of allowing it to climb past six hundred.

Correct Answer: Glucose in the tubule acting as an osmotic diuretic

Once blood glucose passes the renal threshold near one hundred eighty milligrams per deciliter, sugar stays in the tubular fluid and drags water out with it. The resulting water loss triggers intense thirst. Option a is incorrect because holding sodium would expand extracellular volume and reduce urine output rather than increase it. Diabetes actually wastes sodium alongside water during the sugar driven diuresis. Option c is incorrect because protein leaking through injured glomeruli describes established nephropathy, which shows up as foamy urine and edema. It appears after years of disease, not at the first thirst. Option d is incorrect because impaired sodium handling by the tubule is a renal tubular disorder unrelated to sugar. Here the tubule works normally; it simply cannot reabsorb the flood of filtered glucose.

Correct Answer: Sustained tropic stimulation driving cellular hyperplasia

Without iodine the gland cannot build hormone, so negative feedback never switches off. Thyroid stimulating hormone stays high, and because it also makes thyroid cells multiply, the increased cell number enlarges the tissue mass into a goiter. Option a is incorrect because cancer usually shows as a firm fixed solitary nodule with hoarseness or neck nodes, not a diffusely swollen gland in someone whose iodine supply is inadequate and whose tropic hormone is high. Option b is incorrect because autoimmune attack eventually shrinks the gland into fibrous scar once follicles are destroyed. Substrate shortage, not lymphocytic destruction, is what drives this enlargement, and the history points squarely at dietary iodine. Option d is incorrect because colloid is stored inside follicles and does not escape into the neck. Even if it did, spilled protein would cause inflammation rather than the smooth symmetrical growth of a hyperplastic gland.

Correct Answer: Posthepatic jaundice from blocked bile flow

Conjugated bilirubin is water soluble, so when bile cannot reach the duodenum it backs into blood and spills into urine. No pigment reaches the colon, leaving pale stool, and retained bile salts itch. Option b is incorrect because hemolysis raises the unconjugated fraction, which travels bound to albumin and cannot pass the glomerulus. Urine stays clear of bilirubin and stool color deepens rather than fading. Option c is incorrect because hepatocellular injury sends transaminases soaring while alkaline phosphatase climbs only modestly. Here the enzyme pattern is reversed, and stools would not turn uniformly clay colored in simple hepatitis. Option d is incorrect because newborn jaundice reflects immature conjugating enzymes and a high red cell turnover, producing an unconjugated rise. An adult with pale stools and itching does not fit that category at all.

Correct Answer: Metabolic fatty liver improved by weight loss

Fat accumulates in the liver alongside obesity, insulin resistance and dyslipidemia. Losing seven to ten percent of body weight, controlling glucose and exercising are the treatment, since no single drug reverses the process. Option a is incorrect because alcohol is specifically denied here, and its signature is a ratio of aspartate to alanine aminotransferase above two with a raised gamma glutamyl transferase. Neither feature is present. Option b is incorrect because an immune attack on hepatocytes shows high gamma globulins with antinuclear and smooth muscle antibodies, mostly in women. Steroids would not address fat driven by metabolic syndrome. Option c is incorrect because viral infection would be identified by serology rather than by a bright echo pattern on imaging. Direct acting agents clear the virus, yet they do nothing about hepatic fat.