NR-283 Pathophysiology - Set 1 - Part 2

Correct Answer: Primary deficiency of B cell maturation

Maternal IgG crossing the placenta protects the newborn for roughly six months, so a congenital block in B cell maturation stays hidden until that borrowed antibody fades. Pyogenic bacterial infections then begin. Option b is incorrect because a drug the mother took would not produce an inherited pattern running through male relatives. Acquired deficiency in infancy also lacks the clean six month delay seen here. Option c is incorrect because missing terminal complement proteins produce recurrent Neisseria disease, chiefly meningococcal, not the ear and sinus infections of antibody failure. The pattern described points at immunoglobulin, not at complement. Option d is incorrect because malnutrition severe enough to cripple immunity leaves growth failure, low albumin and obvious wasting. This infant grew normally, and diet cannot explain an uncle with the same illness.

Correct Answer: The prodromal period

The prodromal stage is when the host response first produces symptoms, and those symptoms are vague and shared by many illnesses. Clients often describe it exactly this way, and they are frequently highly contagious. Option a is incorrect because incubation runs from exposure until the very first sign appears, and the person feels entirely well throughout. Once fatigue and headache begin, that silent multiplication phase has already ended. Option b is incorrect because the acute stage brings manifestations to their peak, including the signs specific to that organism. Vague tiredness without fever, rash, cough or localized pain has not yet reached that point. Option d is incorrect because convalescence follows the illness, when tissue repairs and strength slowly returns. This client is heading into disease rather than climbing out of it, so recovery cannot describe the timing.

Correct Answer: Interleukin one, interleukin six, and tumor necrosis factor

Macrophages secrete these three cytokines, and they act as endogenous pyrogens, drive malaise through central effects, and instruct the liver to pour out acute phase proteins such as C reactive protein. Option b is incorrect because those vasoactive mediators work locally at the injured site, widening vessels and opening junctions within seconds. None of them reaches the hypothalamus to reset temperature or signals hepatocytes to build new proteins. Option c is incorrect because the kinin system produces pain and vasodilation at the wound, not a systemic fever curve. Hageman factor also launches clotting, yet none of these plasma proteins is a pyrogen. Option d is incorrect because this grouping belongs to eosinophil biology, recruiting and arming cells against helminths and allergens. A client with bacterial pneumonia mounts a neutrophil driven response, and eosinophil mediators do not raise C reactive protein.

Correct Answer: Sharing needles used for injecting drugs

Blood carries a high concentration of virus, so shared injection equipment delivers it straight into the next person's circulation. Semen, vaginal secretions and breast milk are the other fluids that transmit. Option a is incorrect because saliva contains too little virus to infect anyone, and dishes and cups have never spread this infection. Teaching families otherwise deepens stigma without protecting a single person. Option b is incorrect because intact skin is an excellent barrier and no exchange of blood or sexual fluid occurs during ordinary affection. Touch remains safe and is often exactly what the client needs. Option c is incorrect because this enveloped virus dies quickly outside the body and cannot survive on a dry surface. Toilet seats, doorknobs and telephones have never been documented as a source of infection.

Correct Answer: Late incubation and prodrome are highly contagious

Organisms are usually shed near the end of incubation and through the vague prodrome, so a child looks well or merely tired while spreading virus freely. Diagnosis arrives after transmission has occurred. Option a is incorrect because prolonged shedding during recovery does happen with some organisms, salmonella in stool for one, but that occurs after the illness rather than before anyone becomes ill. Option c is incorrect because the order is reversed. Incubation comes first, then the prodrome with its nonspecific complaints, and only afterward does the acute stage bring manifestations to their peak. Option d is incorrect because latency means the organism sits dormant without replicating, as varicella does in dorsal root ganglia for decades. Measles produces no such dormant reservoir, and latency spreads nothing while it lasts.

Correct Answer: Type three, immune complexes trapped in glomeruli

Streptococcal antigen and antibody form soluble complexes that circulate and lodge in the glomerular capillaries. Complement is consumed there, neutrophils arrive and damage the filter, so blood and protein escape into urine. Option a is incorrect because histamine release causes sneezing, hives and bronchospasm within minutes of contact with an allergen. Nothing about a two week interval or a falling complement level fits allergy. Option b is incorrect because antibody fixed directly to basement membrane describes Goodpasture syndrome, which brings hemoptysis alongside hematuria. Here the antigen came from streptococci and was floating in blood before deposition. Option d is incorrect because T cell reactions build granulomas or contact rashes and consume no complement. A dropping C3 level is the fingerprint of antibody driven complement activation instead.

Correct Answer: An unpaired electron propagates a chain reaction

A radical carries an unpaired electron, so it steals one from a neighbor and converts that molecule into a radical too. Damage becomes autocatalytic and races through membrane lipids. Option a is incorrect because receptor binding is a controlled, saturable signaling event that stops when the ligand leaves. Radicals attack whatever molecule is nearest, with no receptor and no off switch. Option c is incorrect because these species live for microseconds and react where they form, so the kidney never gets a chance to filter them. Antioxidant enzymes, not urine, are the real defense. Option d is incorrect because halted protein synthesis is a downstream result of injury rather than the reason radical damage keeps expanding. Ribosome detachment follows energy failure and does not explain propagation.

Correct Answer: Vasodilation with capillary leak emptying the vessels

Cytokines and nitric oxide dilate arterioles while damaged endothelium lets plasma escape into tissue. The client swells and the vascular space empties at the same time, which is why fluid resuscitation continues. Option a is incorrect because a failing heart produces cool clammy skin, distended neck veins and crackles as pressure backs up behind the ventricle. Warm dry skin with a bounding pulse points the other way. Option b is incorrect because hemorrhage empties the circulation without producing widespread swelling, and the skin turns pale and cool. Hemoglobin would fall steadily, and no bleeding source is described in this client. Option d is incorrect because blocked lymphatic drainage causes localized firm swelling in one limb or region, with normal blood pressure. Nothing in that mechanism dilates arterioles or drops systemic vascular resistance.

Correct Answer: High morbidity with low mortality

Morbidity captures the disease rate and the functional impairment a condition leaves behind, while mortality counts deaths. Lasting disability with few deaths is exactly the high morbidity, low mortality pattern. Option a is incorrect because the two labels have been switched. Death rate is low in this report, and it is the residual impairment among living survivors that runs high. Option b is incorrect because incidence counts new cases arising in a period while prevalence counts everyone currently living with the condition. Neither measure speaks to disability, which is what the report emphasizes. Option c is incorrect because a high death rate contradicts the statement that few clients die. Prevalence would indeed be high for a long lasting condition, yet pairing it with heavy mortality misreads the data.

Correct Answer: A sequela of the original stroke

A sequela is the residual abnormality left behind once an acute illness has run its course. The stroke itself is over, and the persistent hemiparesis is its permanent aftermath. Option b is incorrect because a complication is a new problem arising while the original disease is still active, such as aspiration pneumonia during the admission. Timing is what separates the two terms. Option c is incorrect because flares describe chronic conditions that persist and periodically worsen, like lupus or asthma. Nothing here is relapsing; the neurologic deficit has been stable since rehabilitation ended. Option d is incorrect because comorbidity means two conditions coexisting right now and influencing each other, such as diabetes alongside hypertension. Only one disease process is in play, and it has already finished.

Correct Answer: An abnormally folded protein with no nucleic acid

A prion carries no genetic material and simply forces normal brain protein to misfold, spreading the change from molecule to molecule. Because it is a self protein, no inflammation, fever or antibody appears. Option a is incorrect because mycobacterial disease of the nervous system produces fever, elevated inflammatory markers and cerebrospinal fluid changes. A bacterium would also be killed by antibiotics, while this illness runs steadily to death. Option c is incorrect because a reactivating herpesvirus provokes a brisk immune response with fever, cerebrospinal pleocytosis and rising titers. Silence in every inflammatory marker argues strongly against any organism carrying nucleic acid. Option d is incorrect because fungal meningitis such as cryptococcal disease brings headache, fever and organisms visible in spinal fluid. Fungi are living cells that provoke immune reaction, unlike the agent responsible here.

Correct Answer: Sodium potassium pump failure drew water inward

ATP loss stops the pump that exports sodium, so sodium accumulates and water follows osmotically. Hydropic swelling is the earliest change in injured cells, and intact membranes mark it as reversible. Option a is incorrect because programmed death makes cells shrink, condense their chromatin and break into tidy membrane bound fragments. Swelling with vacuoles is the opposite morphology and points toward accidental injury. Option b is incorrect because autolysis would leave a digested, structureless cell rather than recognizable organelles. Intact membranes in this specimen show the hydrolases are still safely contained inside their vesicles. Option d is incorrect because mineral deposits form in tissue that is already dead or scarred, not in cells that are merely swollen. Calcification is a late consequence, and these tubular cells remain alive.

Correct Answer: An overwhelming infection outpacing marrow production

A pronounced left shift with a low or normal total count means the marrow is dumping immature cells and still losing ground. That pattern is more ominous than frank leukocytosis and often signals sepsis. Option a is incorrect because viral illness raises the lymphocyte percentage rather than the band count. Bands are immature neutrophils, so their surge points squarely at bacterial demand and not at a virus clearing up. Option b is incorrect because allergy elevates eosinophils, which are a separate line on the differential entirely. Nothing in an allergic response causes the marrow to release half formed neutrophils into the circulation. Option c is incorrect because dismissing the result as an error would delay treatment in a client who may already be septic. The finding is internally consistent and fits a well described presentation in older adults.

Correct Answer: Donor T cells attacking recipient skin, gut and liver

In graft versus host disease the transplanted immune cells treat the recipient as foreign. Donor cytotoxic lymphocytes attack skin, intestinal lining and bile ducts, which is exactly the triad described. Option b is incorrect because antibody aimed at the graft would show up as failed engraftment with falling blood counts. It would not pick out three specific organs of the host in this pattern. Option c is incorrect because rejection runs in the opposite direction, with host lymphocytes turning on the graft. That failure appears as loss of the new marrow, not as damage to the client's own tissues. Option d is incorrect because complex deposition favors glomeruli, joints and small vessels and brings arthralgia with proteinuria. Palms, bowel and bile ducts are the signature targets of a donor cell attack.

Correct Answer: Kaposi sarcoma of the small vessels

Kaposi sarcoma arises from the endothelium of small blood vessels under the drive of human herpesvirus eight. The purplish painless nonpruritic macules that thicken into nodules are the classic marker of advanced disease. Option a is incorrect because zoster erupts as grouped vesicles on an inflamed base and is intensely painful, following nerve distributions. Flat painless pigmented patches that slowly become nodular do not describe a viral vesicular rash. Option b is incorrect because candidal skin disease looks beefy red and moist in warm folds, with scalloped edges and small satellite spots. Itching and burning dominate, and the color is never purple. Option d is incorrect because pigment left behind by healed inflammation fades over time and stays flat. A lesion that enlarges and rises into a nodule signals a growing tumor rather than residual staining.

Correct Answer: Reperfusion injury from oxygen radicals and calcium

Returning oxygen meets accumulated hypoxanthine and xanthine oxidase, so a burst of radicals forms while calcium floods damaged cells. Recruited neutrophils add more injury, killing myocytes that were still viable. Option a is incorrect because the stem states that blood flow returned, so oxygen delivery has resumed. The paradox here is that restored oxygen itself fuels the damage rather than continuing deprivation. Option b is incorrect because shrinkage of cells is a slow adaptation to reduced workload or lost stimulation, measured in weeks. Infarct expansion over hours reflects active killing, not gradual downsizing of muscle. Option c is incorrect because rejection requires transplanted tissue and preformed antibodies against a donor organ. This client's own heart is involved, and no graft exists for an immune attack to target.

Correct Answer: The fibrous capsule limits drug penetration inside

An abscess is pus sealed inside a fibrous wall with a poor blood supply. Drug delivery depends on perfusion, so antibiotics reach the cavity poorly and the collection usually needs surgical drainage. Option a is incorrect because resistance is a property of the organism itself and would be shown by culture and sensitivity results. Nothing in this presentation identifies a resistant strain, and the anatomy alone explains the failure. Option c is incorrect because creamy yellow drainage is purulent, packed with dead neutrophils, liquefied tissue and organisms. Serous fluid is clear and watery, so calling this collection sterile misreads what the drainage contains. Option d is incorrect because a rising white count is a genuine marrow response to bacterial invasion, not a laboratory artifact. Even a perfectly accurate differential would not change how well a drug crosses an avascular wall.

Correct Answer: Shivering intensifies, raising heat and oxygen demand

Surface cooling while the set point is still high drives harder shivering, and shivering can multiply metabolic rate and oxygen consumption. The temperature climbs faster and the client works harder to get there. Option b is incorrect because a blanket on the skin never touches the thermostat itself. Only an antipyretic that lowers hypothalamic prostaglandin E two can move the set point, and it does so gradually. Option c is incorrect because vasodilation with falling pressure belongs to defervescence, when the set point drops and the client sweats. During the chill the skin vessels are clamped tight, which is why the skin looks pale. Option d is incorrect because interleukin one, interleukin six and tumor necrosis factor keep pouring out as long as the infection persists. External cooling has no effect on macrophage cytokine output at all.

Correct Answer: An altered penicillin binding protein target

The mecA gene gives Staphylococcus aureus a penicillin binding protein with almost no affinity for beta lactams, so every drug in that family loses its binding site. Vancomycin acts at a different target. Option a is incorrect because those enzymes belong to gram negative rods such as Escherichia coli and Klebsiella, and they spare carbapenems. Staphylococci are gram positive, so this laboratory report points to a different route. Option b is incorrect because gram positive organisms have no outer membrane and therefore no porins to lose. Reduced permeability of that kind limits drug entry in Pseudomonas and other enteric organisms instead. Option c is incorrect because pumping a drug back out tends to affect tetracyclines and fluoroquinolones rather than knocking out an entire beta lactam family at once. Efflux also lowers susceptibility gradually rather than abolishing a whole structural class.

Correct Answer: Passive antibody leaves the mother no memory cells

Rh immune globulin is donated anti-D antibody given to clear fetal red cells before the mother can react to them. Because she never mounts a response, nothing is remembered and each pregnancy needs coverage. Option a is incorrect because the placenta moves antibody toward the fetus rather than removing it from the mother. The dose disappears simply through normal protein breakdown over several weeks. Option b is incorrect because passive protection generates no memory cells at all, not merely weak ones. Preventing sensitization is precisely the point, since memory would commit her to attacking every later Rh positive fetus. Option d is incorrect because a rising maternal titre is exactly what the therapy prevents. Detectable anti-D of her own would mean sensitization has already happened, and the globulin would no longer help.