NR-283 Pathophysiology - Set 1 - Part 1

Correct Answer: Histamine stored in mast cell granules

Histamine sits preformed in mast cell granules and spills out within seconds of the sting. It dilates arterioles, opens venular junctions, and irritates sensory nerve endings, producing the wheal and the itch. Option b is incorrect because prostaglandins must be synthesized from membrane arachidonic acid after phospholipase is activated. That manufacturing step takes longer, so these mediators shape the later phase of pain, fever and sustained swelling. Option c is incorrect because interleukin one is a cytokine that macrophages release over hours to drive fever, malaise and hepatic acute phase proteins. Its work is systemic, not a one-minute skin wheal. Option d is incorrect because bradykinin arises when Hageman factor activates the plasma kinin cascade, and its signature effect is firing pain receptors. A wasp sting itches more than it burns at this moment.

Correct Answer: Body temperature lags below a raised set point

Pyrogens have pushed the hypothalamic set point upward, and actual body temperature has not caught up yet. The hypothalamus reads the body as too cold and orders shivering, vasoconstriction and piloerection to generate heat. Option a is incorrect because a temperature sitting above the set point triggers heat loss, so the client would flush, vasodilate and sweat. Cool pale skin and chattering teeth say the opposite is happening. Option b is incorrect because falling prostaglandin E two is what lets the set point drop back, which brings on diaphoresis as the fever breaks. This client is still climbing rather than defervescing. Option c is incorrect because that describes hyperthermia, seen in heat stroke or malignant hyperthermia, where thermostat settings never change. Antipyretics fail in those states, whereas an infected client with a reset thermostat responds to them.

Correct Answer: Chronic inflammation with simultaneous destruction and repair

Mononuclear cells and fibroblasts are the signature of prolonged inflammation, where tissue destruction and attempted repair run at the same time. Fibrosis and progressive loss of joint function follow from that ongoing struggle. Option b is incorrect because neutrophils dominate the opening days of an inflammatory response and are conspicuously absent from this specimen. Marked exudate and swelling would also be expected in a truly acute joint. Option c is incorrect because worms and other parasites summon eosinophils, and no eosinophils were reported here. Rheumatoid disease is autoimmune, so the persistent stimulus is the client's own tissue rather than an organism. Option d is incorrect because resolution means the infiltrate clears and the tissue returns to normal architecture. A joint packed with immune cells and proliferating fibroblasts is doing anything but settling down.

Correct Answer: The reservoir where the organism multiplies

A reservoir is the place where an organism lives and multiplies before reaching anyone. Warm stagnant water in cooling towers and plumbing supports Legionella growth, making the system the environmental source of the outbreak. Option a is incorrect because a portal of exit is the route organisms use to leave a reservoir, such as respiratory droplets or wound drainage. Water is the dwelling place, not the escape route. Option b is incorrect because transmission here happens through the aerosol generated by showers and fountains, which carries organisms into the lungs. The plumbing supplies the bacteria; the mist moves them. Option d is incorrect because the susceptible host is the guest whose defenses allow infection to take hold, often an older smoker with lung disease. Naming the plumbing as the host confuses source with victim.

Correct Answer: The globulin covers the lag before vaccine immunity

Injected antibody works the moment it is given but fades within weeks and leaves no memory. The vaccine takes one to two weeks to generate the client's own durable response, so the two overlap. Option a is incorrect because ready made antibody does not teach B cells anything or amplify their output. It simply occupies the days before the vaccine has produced a protective titre. Option b is incorrect because a vaccine contains antigen, not antibody, so it cannot bind virus at the bite. Weeks pass before the client's plasma cells produce anything capable of neutralizing rabies. Option c is incorrect because only the globulin is preformed antibody. Calling both products passive misses the entire reason for the pairing, since the vaccine exists to build lasting active protection.

Correct Answer: Lipase digestion with calcium soap formation

Escaped pancreatic lipase splits triglycerides into free fatty acids, which combine with calcium in a reaction called saponification. The resulting soaps appear as the firm chalky plaques the surgeon described. Option b is incorrect because denaturation with retained ghost outlines is the coagulative pattern found in an infarcted heart or kidney. It yields a firm pale wedge, not white deposits within fat. Option c is incorrect because enzymes from dying neutrophils turn tissue into thick pus, the hallmark of an abscess. Liquid material would run rather than form the solid nodules described here. Option d is incorrect because walled off collections of macrophages develop in chronic infections such as tuberculosis and certain fungal disease. Acute pancreatitis is a chemical injury, and no organism is being contained.

Correct Answer: It can resolve if the client stops drinking

Fatty change follows impaired triglyceride export and altered fatty acid handling, and the hepatocytes are injured rather than dead. Removing alcohol lets the liver clear the stored lipid over time. Option a is incorrect because dead cells would show a fading or fragmented nucleus and an intensely pink cytoplasm. These hepatocytes still hold their nuclei and continue to function, though poorly. Option b is incorrect because iron pigment appears golden brown and granular, and it collects in hemochromatosis or after repeated transfusion. Clear fat vacuoles look nothing like that, and alcohol drives lipid, not iron. Option d is incorrect because calcium salts deposit in tissue that has already died or scarred, such as old granulomas and damaged valves. Lipid vacuoles inside living cells are a different problem entirely.

Correct Answer: A secondary response driven by memory B cells

Memory B cells from the childhood series survive for decades and activate almost at once on re-exposure. They class switch to IgG, so the titre climbs within days and reaches a far higher peak. Option a is incorrect because a first encounter needs five to fourteen days of clonal expansion before antibody appears, and IgM dominates that slower rise. This client answered in two days. Option b is incorrect because complement proteins circulate ready made and produce no rising titre of any kind. Innate defense lacks memory, so a booster could never make it respond more forcefully. Option c is incorrect because T cell reactions of the delayed type produce local induration over one to three days rather than circulating antitoxin. Toxoid vaccines work by generating neutralizing antibody.

Correct Answer: Fibrous adhesions binding the two surfaces

Fibrinous exudate is rich in fibrinogen that polymerizes into fibrin strands across the inflamed membrane. When those strands are not fully digested, they organize into fibrous bands that tether the surfaces together. Option b is incorrect because fibrin actually does the opposite, meshing around the injured area to wall it off and slow dissemination. Systemic spread reflects a failure to contain infection, not the presence of this exudate. Option c is incorrect because bleeding into a body cavity produces frankly red hemorrhagic fluid from ruptured vessels. The material described here is protein and fibrin, so erythrocytes are not the dominant component. Option d is incorrect because inflammation of a serous membrane thickens and scars it rather than dissolving it away. Chronic fibrinous pericarditis leaves a stiff, constrictive sac, which is a very different outcome from disappearance.

Correct Answer: Cover the viscera with saline moistened sterile gauze

Exposed bowel dries and necroses quickly, so the tissue must be kept moist with sterile normal saline gauze while the surgeon is notified. The client stays flat with knees flexed and nothing by mouth. Option a is incorrect because pushing organs back through a separated wound risks perforating bowel and seeding the peritoneum with contamination. Reduction belongs in the operating room under sterile surgical conditions. Option b is incorrect because dry gauze pulls moisture out of exposed serosa and lets the tissue desiccate. Pressing firmly adds injury to bowel that is already compromised, so both parts of this action are wrong. Option d is incorrect because sitting the client upright increases abdominal tension and pulls the wound further open. Oral intake is also contraindicated, since emergency surgery is coming and the stomach must stay empty.

Correct Answer: The body walled off an agent it cannot eliminate

A caseating granuloma is the classic tuberculous response. Activated macrophages flatten into epithelioid cells, fuse into giant cells, and are ringed by lymphocytes and fibrosis, containing organisms the body cannot clear. Option a is incorrect because a granuloma is itself persistent residual tissue, complete with a fibrous rim and necrotic center. True resolution restores normal architecture and leaves no organized nodule behind on biopsy. Option b is incorrect because primary intention describes a surgical wound whose clean edges are pulled together and closed. That term belongs to skin repair and has no application to an inflammatory nodule inside lung tissue. Option c is incorrect because granuloma formation depends on intact T cell immunity directing macrophage activation. Antibody alone cannot build one, which is why clients with advanced HIV disease may fail to wall off tuberculosis.

Correct Answer: Opsonization marking the organism for phagocytosis

C3b coats the microbe and gives the phagocyte a handle its surface receptors can grip. Opsonization is what makes ingestion efficient, which is why encapsulated organisms that block this coating resist phagocytosis. Option a is incorrect because chemotaxis is the gradient that guides a neutrophil across tissue toward the injury, a job handled largely by C5a. Guidance happens before contact and involves no surface coating. Option c is incorrect because anaphylatoxins act on the host's own mast cells, prompting degranulation with vasodilation and leaking capillaries. Nothing in that description involves attaching a molecule to the bacterial surface. Option d is incorrect because the terminal fragments assemble a pore that lyses the organism outright, destroying it without any phagocyte. This client's neutrophils are still doing the ingesting, so lysis is not the mechanism.

Correct Answer: Anaerobic metabolism from poor tissue perfusion

Microthrombi and maldistributed flow keep oxygen from reaching cells, and mitochondria cannot use what does arrive. Cells switch to anaerobic pathways, and lactate accumulates as the earliest chemical sign of tissue hypoperfusion. Option b is incorrect because lactate is cleared mainly by the liver, and kidney injury is not what drives the level upward in sepsis. Creatinine and urine output track renal function, and neither is described here. Option c is incorrect because fever raises metabolic demand modestly and does not by itself flood the blood with lactate. Without an oxygen supply problem the liver keeps clearing what muscle produces during a temperature spike. Option d is incorrect because blowing off carbon dioxide lowers acid rather than generating it, and the early respiratory alkalosis of sepsis is a compensation. Lactate is produced by cells, not by a change in breathing.

Correct Answer: Integration of viral DNA into host chromosomes

Reverse transcriptase copies the viral RNA into DNA, and integrase splices that DNA into the chromosome of the CD4 cell. The provirus becomes a permanent part of the cell, so therapy suppresses rather than cures. Option a is incorrect because HIV has no affinity for neutrophil granules and does not shelter there. Persistence comes from genetic material written into the host genome, not from a hiding place inside a granulocyte. Option b is incorrect because antibody coating does not shield the virus; antibodies against HIV are plentiful and still fail to clear it. The problem is a genome already written into infected cells. Option d is incorrect because this enveloped virus is fragile outside a host and dies quickly on dry surfaces. Environmental survival plays no part in lifelong infection, which is maintained inside the client's own cells.

Correct Answer: IgA, the antibody of mucosal secretions

Secretory IgA is a dimer released into saliva, tears, mucus and breast milk. It blocks organisms from attaching to the gut epithelium, so pathogens are neutralized at the surface without inflammation. Option b is incorrect because IgD sits on the surface of naive B lymphocytes and works as an antigen receptor. It is present in trace amounts in serum and has no role in milk. Option c is incorrect because IgM appears first when the immune system meets a new antigen and stays largely inside blood vessels. Its bulky pentamer structure keeps it out of mucosal secretions. Option d is incorrect because IgE binds mast cells and triggers histamine release in allergy and in helminth infection. Raising it would produce wheezing and hives, not resistance to intestinal infection.

Correct Answer: The client with measles

Measles spreads in droplet nuclei small enough to hang in the air and drift on currents, so it demands a negative pressure room and a fitted respirator. The other three travel as large droplets. Option a is incorrect because influenza particles are heavy, fall within a short distance and land on nearby mucous membranes. A surgical mask and a private room handle that risk without special ventilation. Option b is incorrect because whooping cough travels on large respiratory particles thrown a short distance during coughing fits. Droplet precautions in an ordinary private room contain it, and no airflow engineering is required. Option c is incorrect because Neisseria meningitidis reaches a new host in large droplets during close contact and stops being infectious soon after effective antibiotics begin. It never requires an airborne isolation room.

Correct Answer: Nosocomial infection and iatrogenic event

The infection was acquired inside the facility, which makes it nosocomial, and it followed directly from a device inserted as treatment, which makes it iatrogenic as well. Both labels fit. Option a is incorrect because idiopathic means the cause cannot be identified, yet the catheter is an obvious source. Congenital problems are present at birth, which a hospital acquired infection clearly is not. Option b is incorrect because those words describe stages in the timeline of an illness rather than its origin. One names vague early symptoms and the other names silent disease found only by testing. Option d is incorrect because endemic refers to a disease steadily present in a geographic population, a population level idea. Multifactorial describes several converging causes, which does not capture a single catheter as the source.

Correct Answer: Loss of cilia halts mucociliary clearance

Squamous cells tolerate smoke better but carry no cilia and secrete no mucus, so the escalator that normally sweeps trapped organisms upward is gone. Secretions pool in the airway and infection follows. Option a is incorrect because the replacement epithelium is actually a tougher, more resistant barrier than the delicate columnar layer it displaced. Thinning is not what happens; the defect lies in lost clearance, not lost strength. Option c is incorrect because surfactant is produced by alveolar type two cells far distal to the bronchial lining described here. Metaplasia of conducting airway epithelium leaves surfactant production entirely untouched. Option d is incorrect because epithelial replacement occurs in the mucosal lining, while the smooth muscle beneath it retains normal contractile protein. Bronchoconstriction still occurs in smokers, so muscle failure cannot explain their infections.

Correct Answer: Ruptured membranes spill contents into tissue

Necrotic cells swell until their membranes give way, and the released enzymes and proteins irritate the surrounding tissue. That spill always draws an acute inflammatory response into the dead zone. Option a is incorrect because caspases are the executioner enzymes of programmed death, and that pathway is deliberately quiet. Necrosis runs on lysosomal hydrolases instead, with no caspase involvement at all. Option b is incorrect because shrinkage describes apoptosis, where a single cell pulls in on itself and vanishes silently. Cells killed by ischemia swell instead, and whole contiguous blocks of them die together. Option c is incorrect because sealed fragments are cleared by neighboring cells and macrophages without summoning neutrophils. Their whole purpose is disposal that leaves no trace, which is why no redness or swelling appears.

Correct Answer: Natural active immunity produced by the infection

Having the disease exposed the adult's own lymphocytes to the virus, and they generated antibody and memory cells. That response came from ordinary life rather than a clinician, and it has lasted for decades. Option a is incorrect because a vaccine would have supplied the antigen deliberately in a clinic. This adult met the wild virus during an ordinary childhood illness, which makes the route natural. Option c is incorrect because maternal antibody crossing the placenta or arriving in milk fades within months of birth. Nothing borrowed in infancy could still be protecting an adult decades later. Option d is incorrect because injected immune globulin protects for weeks at most and teaches the recipient nothing. No product was given here, and the protection has held since childhood.