D236 Pathophysiology - Set 4 - Part 1

Correct Answer: Massive hemorrhage

Esophageal varices from portal hypertension can rupture causing life-threatening upper gastrointestinal bleeding requiring emergency intervention immediately.
Option a is incorrect because pulmonary embolism involves blood clots in lungs, not bleeding from dilated esophageal veins.
Option c is incorrect because while blood loss can cause cardiac problems, the primary complication is hemorrhage itself.
Option d is incorrect because respiratory failure isn't the direct result of variceal rupture; bleeding is the complication.

Correct Answer: Calcium signaling

Calcium signaling involves calcium release from stores or influx triggering cellular responses including gene transcription changes.
Option a is incorrect because cAMP is a different second messenger system, though calcium can interact with it.
Option c is incorrect because lipid messengers like IP3 work differently, though they can trigger calcium release secondarily.
Option d is incorrect because gas signaling uses nitric oxide or carbon monoxide, not calcium as messenger.

Correct Answer: Cortisol deficiency

Cortisol synthesis blockade causes precursor shunting to androgen production, causing virilization and ambiguous genitalia in females.
Option a is incorrect because insulin problems cause diabetes, not the adrenal hormone imbalance causing genital ambiguity.
Option c is incorrect because thyroid hormone affects metabolism and development but not genital differentiation described here.
Option d is incorrect because growth hormone affects stature and growth, not adrenal steroid synthesis pathways.

Correct Answer: Phagolysosome escape

Some bacteria escape phagolysosomes or prevent fusion, surviving intracellularly within macrophages causing chronic infections like tuberculosis.
Option a is incorrect because capsules prevent phagocytosis initially but don't help survival once bacteria are engulfed.
Option c is incorrect because spores resist environmental stress but this isn't the intracellular survival mechanism described.
Option d is incorrect because biofilms form on surfaces, not the intracellular macrophage survival mechanism described here.

Correct Answer: Vasodilation widespread

Septic shock causes massive vasodilation from inflammatory mediators, dropping vascular resistance and blood pressure dangerously despite cardiac compensation.
Option a is incorrect because septic shock involves vascular tone loss, not actual blood volume depletion initially.
Option c is incorrect because cardiac output typically increases initially in septic shock, not heart failure.
Option d is incorrect because respiratory problems are secondary; the primary issue is vascular tone loss described.

Correct Answer: Lactase enzyme

Lactase deficiency prevents lactose breakdown into glucose and galactose, causing osmotic diarrhea and fermentation symptoms.
Option a is incorrect because amylase digests starches, not the milk sugar lactose causing symptoms described here.
Option c is incorrect because lipase digests fats; lactose is a carbohydrate requiring specific lactase enzyme activity.
Option d is incorrect because proteases digest proteins, not the lactose sugar causing intolerance symptoms described.

Correct Answer: IgM antibody

IgM antibodies appear first during primary immune responses, indicating acute or recent infection before IgG develops.
Option a is incorrect because IgG appears later providing long-term immunity, not the initial acute response marker.
Option c is incorrect because IgA provides mucosal immunity but isn't the first systemic antibody during infections.
Option d is incorrect because IgD functions in B cell activation, not as primary marker of acute infection.

Correct Answer: Vasospasm episodes

Raynaud phenomenon involves episodic vasospasm of digital arteries causing characteristic white-blue-red color changes with temperature.
Option a is incorrect because thrombosis causes persistent ischemia, not the reversible episodic changes of Raynaud phenomenon.
Option c is incorrect because atherosclerosis causes chronic narrowing, not the acute reversible spasms described here.
Option d is incorrect because aneurysms are vessel dilations, not the vasospastic episodes causing Raynaud symptoms.

Correct Answer: Pulmonary hypertension

Chronic lung disease causes pulmonary hypertension, forcing the right ventricle to hypertrophy and potentially fail.
Option a is incorrect because left heart failure causes different patterns; cor pulmonale specifically involves right heart changes.
Option c is incorrect because systemic hypertension affects left ventricle primarily, not the right heart changes described.
Option d is incorrect because coronary disease affects heart muscle blood supply, not the pressure overload causing cor pulmonale.

Correct Answer: Helper T cells

Helper T cells release cytokines coordinating immune responses, essential for B cell antibody production and cytotoxic T cell activation.
Option a is incorrect because natural killer cells provide innate immunity against viruses and tumors, not adaptive coordination.
Option c is incorrect because suppressor cells regulate immune responses but don't primarily coordinate adaptive immunity described.
Option d is incorrect because memory B cells provide rapid secondary responses but don't coordinate overall adaptive immunity.

Correct Answer: Beta amyloid

Beta amyloid peptides aggregate forming extracellular plaques in Alzheimer disease, disrupting neural function and triggering inflammation.
Option b is incorrect because alpha synuclein forms Lewy bodies in Parkinson disease, not Alzheimer amyloid plaques.
Option c is incorrect because huntingtin protein mutations cause Huntington disease, not the amyloid plaques described.
Option d is incorrect because tau forms intracellular tangles in Alzheimer's, not the extracellular amyloid plaques.

Correct Answer: Massive mediator release

Anaphylaxis involves massive simultaneous mast cell degranulation releasing histamine and mediators causing systemic symptoms rapidly.
Option a is incorrect because anaphylaxis involves rapid massive release, not slow histamine release over time.
Option c is incorrect because sensitization occurs before anaphylaxis; the acute reaction involves rapid mediator release.
Option d is incorrect because anaphylaxis is immediate Type I hypersensitivity, not delayed reaction described.

Correct Answer: ACTH hormone

ACTH elevation in Addison disease stimulates melanocytes causing hyperpigmentation, as ACTH shares structure with melanocyte-stimulating hormone.
Option a is incorrect because cortisol is deficient in Addison disease, not elevated to cause pigmentation changes.
Option c is incorrect because insulin regulates glucose metabolism, not the skin pigmentation seen in Addison disease.
Option d is incorrect because thyroid hormone affects metabolism broadly but doesn't cause the bronze pigmentation described.

Correct Answer: Alpha-1 antitrypsin

Alpha-1 antitrypsin deficiency allows neutrophil elastase to destroy lung elastic tissue unchecked, causing early emphysema development.
Option a is incorrect because surfactant deficiency causes respiratory distress syndrome, not the emphysema pattern described here.
Option c is incorrect because fibrinogen is a clotting protein; its deficiency doesn't cause lung tissue destruction.
Option d is incorrect because albumin maintains oncotic pressure; its deficiency doesn't cause emphysema development described.

Correct Answer: Receptor dysfunction

Insulin resistance involves defective receptor signaling preventing normal glucose uptake despite adequate or elevated insulin levels.
Option a is incorrect because type 2 diabetes initially has normal or high insulin; the problem is cellular resistance.
Option c is incorrect because glucose excess is the result of insulin resistance, not the cause of resistance.
Option d is incorrect because pancreas destruction causes type 1 diabetes; type 2 involves resistance, not destruction.

Correct Answer: Carboxyhemoglobin color

Carboxyhemoglobin has bright cherry-red color giving pink appearance despite preventing oxygen delivery to tissues effectively.
Option a is incorrect because circulation changes don't explain the specific pink coloration despite hypoxia present.
Option c is incorrect because vasodilation might contribute but the carboxyhemoglobin color is the primary factor.
Option d is incorrect because skin thickness doesn't change; the hemoglobin-CO complex creates the pink appearance.

Correct Answer: Endothelial dysfunction

Eclampsia involves widespread endothelial dysfunction causing vasospasm, organ hypoperfusion, and seizures from cerebral involvement occurring.
Option a is incorrect because while glucose issues can occur in pregnancy, eclampsia specifically involves vascular dysfunction.
Option c is incorrect because hormone imbalances don't directly cause the endothelial damage and seizures of eclampsia.
Option d is incorrect because eclampsia results from placental and vascular factors, not infectious causes primarily.

Correct Answer: Trisomy 21

Trisomy 21 causes Down syndrome with characteristic features including intellectual disability, facial dysmorphism, and cardiac defects.
Option a is incorrect because trisomy 13 causes Patau syndrome with different severe abnormalities than Down syndrome.
Option c is incorrect because trisomy 18 causes Edwards syndrome with different features than Down syndrome described.
Option d is incorrect because monosomy X causes Turner syndrome affecting females, not Down syndrome characteristics.

Correct Answer: Indirect bilirubin

Unconjugated or indirect bilirubin accumulates when immature liver cannot conjugate it efficiently, causing neonatal jaundice.
Option a is incorrect because direct bilirubin is already conjugated; the problem is with unconjugated bilirubin processing.
Option c is incorrect because bile acids cause different problems; jaundice results from bilirubin accumulation specifically.
Option d is incorrect because hemoglobin breaks down to bilirubin; it's the bilirubin that causes jaundice.

Correct Answer: Antibody stimulation

Thyroid-stimulating antibodies cross-react with orbital tissues causing inflammation, fat expansion, and eye protrusion in Graves disease.
Option a is incorrect because Graves involves thyroid stimulation, not destruction which would cause hypothyroidism instead.
Option c is incorrect because iodine deficiency causes goiter, not the autoimmune exophthalmos of Graves disease.
Option d is incorrect because exophthalmos in Graves results from inflammatory expansion, not tumor growth behind eyes.